Isobutyrylglycine is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acyl glycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13) which is an enzyme that catalyzes the chemical reaction: acyl-CoA + glycine < -- > CoA + N-acylglycine. Isobutyrylglycine is identified in large amount in urine of patients with isobutyryl-CoA dehydrogenase deficiency. Isobutyryl-CoA dehydrogenase deficiency is a disorder caused by the deficiency of isobutyryl-CoA dehydrogenase that is involved in the catabolism of the branched-chain amino acid valine (PMID 15505379). Moreover, Isobutyrylglycine is found to be associated with ethylmalonic encephalopathy and propionic acidemia, which are also inborn errors of metabolism. Isobutyrylglycine is a biomarker for the consumption of cheese.
Isovalerylglycine (IVG) is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acyl glycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13) which is an enzyme that catalyzes the chemical reaction: acyl-CoA + glycine < -- > CoA + N-acylglycine. Isovalerylglycine is a byproduct of the catabolism of the aminoacid leucine. Accumulation of isovalerylglycine occurs in Isovaleric Acidemia (IVA). IVA (OMIM/ McKusick 243500) is an autosomal recessive disorder caused by mutations in the isovaleryl-CoA dehydrogenase (EC 1.3.99.10) gene. The deficiency of this enzyme in the metabolism of leucine leads to the accumulation of a series of isovaleryl-CoA metabolites, such as isovalerylglycine. It is very important to caution for false positive results when screening for isovaleric acidemia by tandem mass spectrometry based on dried blood-spot levels of C5-acylcarnitines, including isovalerylcarnitine and its isomer, pivaloylcarnitine; pivaloylcarnitine is derived from pivalate-generating antibiotics, and has caused many false-positive results (PMID: 17850781). Isovalerylglycine is a biomarker for the consumption of cheese.
N-Methylalanine, also known as (S)-2-methylaminopropanoate or N-methyl-L-alanine, is classified as an alanine or an alanine derivative. Alanines are compounds containing alanine or a derivative thereof resulting from reaction of alanine at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom. N-Methylalanine is considered to be soluble (in water) and acidic. (ChemoSummarizer)
2-(Methylamino)benzoic acid is found in citrus. 2-(Methylamino)benzoic acid is isolated from grapefruit peel oi
N-Methyl-D-aspartic acid is an amino acid derivative acting as a specific agonist at the NMDA receptor, and therefore mimics the action of the neurotransmitter glutamate on that receptor. In contrast to glutamate, NMDA binds to and regulates the above receptor only, but not other glutamate receptors. NMDA is a water-soluble endogenous metabolite that plays an important role in the neuroendocrine system of species across Animalia (PMID:18096065). It was first synthesized in the 1960s (PMID:14056452). NMDA is an excitotoxin; this trait has applications in behavioural neuroscience research. The body of work utilizing this technique falls under the term "lesion studies." Researchers apply NMDA to specific regions of an (animal) subject's brain or spinal cord and subsequently test for the behaviour of interest, such as operant behaviour. If the behaviour is compromised, it suggests that the destroyed tissue was part of a brain region that made an important contribution to the normal expression of that behaviour. Examples of antagonists of the NMDA receptor are ketamine, amantadine, dextromethorphan (DXM), riluzole, and memantine. They are commonly referred to as NMDA receptor antagonists (PMID:28877137).
N-Methyl-L-proline, also known as N-methyl-L-proline, (2S)-1-methylpyrrolidine-2-carboxylic acid, hydric acid, or monomethyl proline, is classified as a proline or a proline derivative. It is not naturally produced by humans and can only be obtained from the diet. In particular, it is a metabolically inert cell protectant found in many plants and is used by plants to protect against extremes in osmolarity and growth temperatures. N-Methyl-L-proline is found in the fruit juices of yellow orange, blood orange, lemon, mandarin, and bitter orange (PMID: 21838291).
N-Acetylhistamine is a 4-(beta-Acetylaminoethyl)imidazole that is an intermediate in Histidine metabolism. It is generated from Histamine via the enzyme Transferases (EC 2.3.1.-). Histamine is an amine derived by enzymatic decarboxylation of histidine. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter.
N2,N2-Dimethylguanosine is an urinary nucleoside, a primary degradation product of tRNA. The mean levels of urinary N2,N2-Dimethylguanosine in the patients with colorectal cancer are significantly higher than those in patients with intestinal villous adenoma or the healthy adults (PMID 15991285). N2,N2-Dimethylguanosine has been identified in the human placenta (PMID: 32033212).
2-Methylguanosine is an endogenous methylated nucleoside found in human fluids; methylated purine bases are present in higher amounts in tumor-bearing patients compared to healthy controls.DNA hypermethylation is a common finding in malignant cells and has been explored as a therapeutic target for hypomethylating agents. When chemical bonds to DNA, the DNA becomes damaged and proper and complete replication cannot occur to make the normal intended cell. A DNA adduct is an abnormal piece of DNA covalently-bonded to a cancer-causing chemical. This has shown to be the start of a cancerous cell, or carcinogenesis. DNA adducts in scientific experiments are used as bio-markers and as such are themselves measured to reflect quantitatively, for comparison, the amount of cancer in the subject. (PMID: 17336316, 17154124, 3506820, 17044778, 17264127).
Riboprine, also known as isopentenyladenosine or ipa, is a member of the class of compounds known as purine nucleosides. Purine nucleosides are compounds comprising a purine base attached to a ribosyl or deoxyribosyl moiety. Riboprine is slightly soluble (in water) and a very weakly acidic compound (based on its pKa). Riboprine can be found in a number of food items such as peppermint, chinese mustard, custard apple, and green bean, which makes riboprine a potential biomarker for the consumption of these food products.
N8-Acetylspermidine is a polyamine. The polyamines, found in virtually all living organisms, are a ubiquitous group of compounds that appear to play a vital role in many cellular processes involving nucleic acids including cell growth and differentiation. Acetylation on the terminal nitrogen adjacent to the 4-carbon chain produces N8-acetylspermidine. This reaction is catalyzed by spermidine N8-acetyltransferase and does not result in the conversion of spermidine to putrescine. Instead, the product undergoes deacetylation. This acetyltransferase appears to be associated with chromatin in the cell nucleus and has been reported to be the same as (or related to) the enzyme(s) responsible for histone acetylation. N8-Acetylspermidine does not accumulate in tissues but rather appears to be rapidly deacetylated back to spermidine by a relatively specific cytosolic deacetylase, N8-acetylspermidine deacetylase. The function of this N8-acetylation/deacetylation pathway in cellular processes is not understood clearly, but several observations have suggested a role in cell growth and differentiation (PMID: 12093478).
Nalbuphine is only found in individuals that have used or taken this drug. It is a narcotic used as a pain medication. It appears to be an agonist at kappa opioid receptors and an antagonist or partial agonist at mu opioid receptors. [PubChem]The exact mechanism of action is unknown, but is believed to interact with an opiate receptor site in the CNS (probably in or associated with the limbic system). The opiate antagonistic effect may result from competitive inhibition at the opiate receptor, but may also be a result of other mechanisms. Nalbuphine is thought primarily to be a kappa agonist. It is also a partial mu antagonist analgesic, with some binding to the delta receptor and minimal agonist activity at the sigma receptor.
Nandrolone is a C18 steroid with androgenic and anabolic properties. It is generally prepared from alkyl ethers of estradiol to resemble testosterone, but it has one less carbon atom at the 19 position (Pubchem). Nandrolone is an anabolic steroid occurring naturally in the human body, albeit in small quantities. Nandrolone is most commonly sold commercially as its decanoate ester (Deca-Durabolin) and less commonly as a phenylpropionate ester (Durabolin). Nandrolone use is indirectly detectable in urine tests by testing for the presence of 19-norandrosterone, a metabolism product of this molecule. The International Olympic Committee has set a limit of 2 ng per ml of urine as the upper limit, beyond which an athlete is suspected of doping (Wikipedia).
Naringin, also known as naringoside or naringin hydrate, is a flavanone-7-O-glycoside between the flavanone naringenin and the disaccharide neohesperidose. Naringin belongs to the flavonoid family. Flavonoids consist of 15 carbon atoms in 3 rings, 2 of which must be benzene rings connected by a 3 carbon chain.  Naringin contains the basic flavonoid structure along with one rhamnose and one glucose unit attached to its aglycone portion, called naringenin, at the 7-carbon position. The steric hindrance provided by the two sugar units makes naringin less potent than its aglycone counterpart, naringenin. Naringin is a bitter tasting compound. Naringin is found, on average, in the highest concentration within a few different foods, such as rosemaries, grapefruit/pummelo hybrids, and grapefruits and in a lower concentration in grape wines, pummelo, and beers. Naringin has also been detected, but not quantified in several different foods, such as citrus, limes, herbs and spices, common oregano, and mandarin orange (clementine, tangerine). Both naringin and hesperetin, which are the aglycones of naringin and hesperidin, occur naturally in citrus fruits. Naringin is the major flavonoid glycoside in grapefruit and gives grapefruit juice its bitter taste. Narinigin exerts a variety of pharmacological effects such as antioxidant activity, blood lipid-lowering, anticarcinogenic activity, and inhibition of selected cytochrome P450 enzymes including CYP3A4 and CYP1A2, which may result in several drug interactions in-vitro.
Nefazodone hydrochloride (trade name Serzone) is an antidepressant drug marketed by Bristol-Myers Squibb. Its sale was discontinued in 2003 in some countries, due to the small possibility of hepatic (liver) injury, which could lead to the need for a liver transplant, or even death. The incidence of severe liver damage is approximately 1 in 250,000 to 300,000 patient-years. On May 20, 2004, Bristol-Myers Squibb discontinued the sale of Serzone in the United States. [Wikipedia]
Nelfinavir is only found in individuals that have used or taken this drug. It is a potent HIV-1 protease inhibitor. It is used in combination with other antiviral drugs in the treatment of HIV in both adults and children. [PubChem]Nelfinavir inhibits the HIV viral proteinase enzyme which prevents cleavage of the gag-pol polyprotein, resulting in noninfectious, immature viral particles.
Niacinamide, also known as nicotinamide (NAM), is a form of vitamin B3 found in food and used as a dietary supplement and medication. Niacinamide belongs to the class of organic compounds known as nicotinamides. These are heterocyclic aromatic compounds containing a pyridine ring substituted at position 3 by a carboxamide group. Its primary significance is in the prevention and/or cure of blacktongue and pellagra. The structure of nicotinamide consists of a pyridine ring to which a primary amide group is attached in the meta position. It is an amide of nicotinic acid. As an aromatic compound, it undergoes electrophilic substitution reactions and transformations of its two functional groups. Niacinamide and phosphoribosyl pyrophosphate can be converted into nicotinic acid mononucleotide and phosphate by the enzyme nicotinamide phosphoribosyltransferase. In humans, niacinamide is involved in the metabolic disorder called the nad+ signalling pathway (cancer). Niacinamide is an odorless tasting compound. Outside of the human body, niacinamide is found, on average, in the highest concentration within a few different foods, such as common sages, cow milk, and cocoa beans and in a lower concentration in common pea. Niacinamide has also been detected, but not quantified in several different foods, such as yardlong beans, roselles, apples, oyster mushrooms, and swiss chards. Niacinamide occurs in trace amounts mainly in meat, fish, nuts, and mushrooms, as well as to a lesser extent in some vegetables. It is commonly added to cereals and other foods. Many multivitamins contain 20–30 mg of vitamin B3 and it is also available in higher doses. Most animals cannot manufacture this compound in amounts sufficient to prevent nutritional deficiency and it therefore must be supplemented through dietary intake.
Nicotinic acid, also known as niacin or vitamin B3, is a water-soluble vitamin whose derivatives such as NADH, NAD, NAD+, and NADP play essential roles in energy metabolism in the living cell and DNA repair. The designation vitamin B3 also includes the amide form, nicotinamide or niacinamide. Severe lack of niacin causes the deficiency disease pellagra, whereas a mild deficiency slows down the metabolism decreasing cold tolerance. The recommended daily allowance of niacin is 2-12 mg a day for children, 14 mg a day for women, 16 mg a day for men, and 18 mg a day for pregnant or breast-feeding women. It is found in various animal and plant tissues and has pellagra-curative, vasodilating, and antilipemic properties. The liver can synthesize niacin from the essential amino acid tryptophan, but the synthesis is extremely slow and requires vitamin B6; 60 mg of tryptophan are required to make one milligram of niacin. Bacteria in the gut may also perform the conversion but are inefficient.
Nicotinuric acid is an acylglycine. Acylglycines are normally minor metabolites of fatty acids. However, the excretion of certain acylglycines is increased in several inborn errors of metabolism. In certain cases, the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acylglycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13) which is an enzyme that catalyzes the chemical reaction acyl-CoA + glycine <-> CoA + N-acylglycine. Nicotinuric acid is the major detoxification product of nicotinic acid. It may serve as a simple quantitative index of hepatic biotransformation of nicotinic acid (PMID:3243933).
Nifedipine has been formulated as both a long- and short-acting 1,4-dihydropyridine calcium channel blocker. It acts primarily on vascular smooth muscle cells by stabilizing voltage-gated L-type calcium channels in their inactive conformation. By inhibiting the influx of calcium in smooth muscle cells, nifedipine prevents calcium-dependent myocyte contraction and vasoconstriction. A second proposed mechanism for the drug's vasodilatory effects involves pH-dependent inhibition of calcium influx via inhibition of smooth muscle carbonic anhydrase. Nifedipine is used to treat hypertension and chronic stable angina.
Nimodipine is a 1,4-dihydropyridine calcium channel blocker. It acts primarily on vascular smooth muscle cells by stabilizing voltage-gated L-type calcium channels in their inactive conformation. By inhibiting the influx of calcium in smooth muscle cells, nimodipine prevents calcium-dependent smooth muscle contraction and subsequent vasoconstriction. Compared to other calcium channel blocking agents, nimodipine exhibits greater effects on cerebral circulation than on peripheral circulation. Nimodipine is used to as an adjunct to improve the neurologic outcome following subarachnoid hemorrhage from ruptured intracranial aneurysm.
Nitazoxanide, also known by the brand name Alinia, is a synthetic nitrothiazolyl-salicylamide derivative and an anti-protozoal agent. It is approved for treatment of infectious diarrhea caused by Cryptosporidium parvum and Giardia lamblia in patients 1 year of age and older. Following oral administration it is rapidly hydrolyzed to its active metabolite, tizoxanide, which is 99% protein bound. Peak concentrations are observed 1-4 hours after administration. It is excreted in the urine, bile and feces. Untoward effects include abdominal pain, vomiting and diarrhea. [Wikipedia]
Nitrazepam is only found in individuals that have used or taken this drug. It is a benzodiazepine derivative used as an anticonvulsant and hypnotic.Nitrazepam belongs to a group of medicines called benzodiazepines. It acts on benzodiazepine receptors in the brain which are associated with the GABA receptors causing an enhanced binding of GABA (gamma amino butyric acid) to GABAA receptors. GABA is a major inhibitory neurotransmitter in the brain, involved in inducing sleepiness, muscular relaxation and control of anxiety and fits, and slows down the central nervous system. The anticonvulsant properties of nitrazepam and other benzodiazepines may be in part or entirely due to binding to voltage-dependent sodium channels rather than benzodiazepine receptors. Sustained repetitive firing seems to be limited by benzodiazepines effect of slowing recovery of sodium channels from inactivation.
Nizatidine is only found in individuals that have used or taken this drug. It is a histamine H2 receptor antagonist with low toxicity that inhibits gastric acid secretion. The drug is used for the treatment of duodenal ulcers. [PubChem]Nizatidine competes with histamine for binding at the H<sub>2</sub>-receptors on the gastric basolateral membrane of parietal cells. Competitive inhibition results in reduction of basal and nocturnal gastric acid secretions. The drug also decreases the gastric acid response to stimuli such as food, caffeine, insulin, betazole, or pentagastrin.
Nobiletin is found in citrus. Nobiletin is isolated from peel of king orange (Citrus nobilis), seville orange (Citrus aurantium) and other Citrus species, and the round kumquat (Fortunella japonica
L-Norleucine, also known as L-aminohexanoate or caprine, belongs to the class of organic compounds known as l-alpha-amino acids. These are alpha amino acids which have the L-configuration of the alpha-carbon atom. Thus, L-norleucine is considered to be a fatty acid lipid molecule. An unnatural amino acid that is used experimentally to study protein structure and function. L-Norleucine is a very hydrophobic molecule, practically insoluble in water, and relatively neutral. L-Norleucine exists in all eukaryotes, ranging from yeast to humans. Outside of the human body, L-Norleucine has been detected, but not quantified in cow milk. This could make L-norleucine a potential biomarker for the consumption of these foods. It binds reversibly to the kringle domain of plasminogen and blocks the binding of plasminogen to fibrin and its activation to plasmin.
Nornicotine is an alkaloid extracted from tobacco and related to nicotine but having a lower toxicity: used as an agricultural and horticultural insecticide.
(-)-alpha-Narcotine is found in opium poppy. (-)-alpha-Narcotine is an alkaloid from Papaver somniferum (opium poppy).Noscapine (also known as Narcotine, Nectodon, Nospen, and Anarcotine) is a benzylisoquinoline alkaloid from plants of the Papaveraceae family, without significant painkilling properties. This agent is primarily used for its antitussive (cough-suppressing) effects. It has also been shown to have anticancer activity. (Wikipedia).
O-Acetylserine is an α-amino acid with the chemical formula HO2CCH(NH2)CH2OC(O)CH3. It is an intermediate in the biosynthesis of the common amino acid cysteine in bacteria and plants. O-Acetylserine is biosynthesized by acetylation of the serine by the enzyme serine transacetylase. The enzyme O-acetylserine (thiol)-lyase, using sulfide sources, converts this ester into cysteine, releasing acetate. O-Acetylserine belongs to the class of organic compounds known as l-alpha-amino acids. These are alpha amino acids which have the L-configuration of the alpha-carbon atom. O-Acetylserine (OASS) is an acylated amino acid derivative. O-Acetylserine exists in all living species, ranging from bacteria to humans. Outside of the human body, O-Acetylserine has been detected, but not quantified in several different foods, such as okra, vaccinium (blueberry, cranberry, huckleberry), rapes, sparkleberries, and lingonberries. This could make O-acetylserine a potential biomarker for the consumption of these foods.
O-Phosphoethanolamine, also known as PEA, phosphorylethanolamine, colamine phosphoric acid or ethanolamine O-phosphate, belongs to the class of organic compounds known as phosphoethanolamines. Phosphoethanolamines are compounds containing a phosphate linked to the second carbon of an ethanolamine. O-Phosphoethanolamine is used in the biosynthesis of two different types of phospholipids: glycerophospholipids and sphingolipids. O-Phosphoethanolamine exists in all living species, ranging from bacteria to plants to humans. Within humans, O-phosphoethanolamine participates in a number of enzymatic reactions. In particular, cytidine triphosphate and O-phosphoethanolamine can be converted into CDP-ethanolamine; which is mediated by the enzyme ethanolamine-phosphate cytidylyltransferase. In addition, O-phosphoethanolamine can be biosynthesized from ethanolamine; which is catalyzed by the enzyme choline/ethanolamine kinase. In humans, O-phosphoethanolamine is involved in phosphatidylcholine biosynthesis. O-phosphoethanolamine is also a product of the metabolism of sphingolipids. In particular, sphinglipids are metabolized in vivo to phosphorylethanolamine and a fatty aldehyde, generally palmitaldehyde. Both metabolites are ultimately converted to glycerophospholipids. The lipids are first phosphorylated by a kinase and then cleaved by the pyridoxal-dependent sphinganine-1-phosphate aldolase. Elevated urine levels of O-Phosphoethanolamine or PEA can be used to help in the diagnosis of Hypophosphatasia (HPP). Reference ranges for urinary PEA vary according to age and somewhat by diet, and follow a circadian rhythm. Outside of the human body, O-phosphoethanolamine has been detected, but not quantified in, several different foods, such as oxheart cabbages, anises, shiitakes, abalones, and teffs.
Phosphoserine is the phosphoric acid ester of the amino acid serine. It is found in essentially all living organisms ranging from microbes to plants to mammals. Phosphoserine is a component of many proteins as the result of posttranslational modifications to the native protein‚Äôs serine residue(s). The phosphorylation of the hydroxyl functional group in serine to produce phosphoserine is catalyzed by various types of kinases. Serine is one of three amino acid residues that are commonly phosphorylated by kinases during cell signalling in eukaryotes. Free phosphoserine is found in many biofluids and likely arises from the proteolysis of proteins containing phosphoserine residues (PMID: 7693088).
Phosphothreonine is a phosphoamino acid. It is the phosphorylated ester of threonine. There are three amino acids that are typically phosphorylated in eukaryotes: serine, threonine, and tyrosine. Threonine residues in endogenous proteins undergo phosphorylation through the action of a threonine kinase. Small amounts of free phosphothreonine can be detected in urine [PMID: 7693088].
Octadecanedioic acid, also known as 1,18-octadecanedioate or octadecane-1,18-dioate, belongs to the class of organic compounds known as long-chain fatty acids. These are fatty acids with an aliphatic tail that contains between 13 and 21 carbon atoms. In the case of octadecanedioic acid, it has carboxyl groups at both ends of the chain, not just one.  Octadecanedioic acid is a very hydrophobic molecule, practically insoluble (in water).  Octadecanedioic acid is a long-chain dicarboxylic acid normally not found in humans that has been identified in the blood serum in Reye's syndrome patients (PMID:¬†3746531).  There may also be an association with colorectal cancer (PMID: 25037050).
Olmesartan is an antihypertensive agent which belongs to the class of medicines called angiotensin II receptor antagonists. It acts rapidly to lower high blood pressure. It is marketed worldwide by Daiichi Sankyo, Ltd. and in the United States by Daiichi Sankyo, Inc. and Forest Laboratories.
Used to treat allergic conjunctivitis (itching eyes), olopatadine inhibits the release of histamine from mast cells. It is a relatively selective histamine H1 antagonist that inhibits the in vivo and in vitro type 1 immediate hypersensitivity reaction including inhibition of histamine induced effects on human conjunctival epithelial cells.
Omeprazole is a highly effective inhibitor of gastric acid secretion used in the therapy of stomach ulcers, dyspepsia, peptic ulcer disease , gastroesophageal reflux disease and Zollinger-Ellison syndrome. The drug inhibits the H(+)-K(+)-ATPase (H(+)-K(+)-exchanging ATPase) in the proton pump of Gastric Parietal Cells.--Pubchem. Omeprazole is one of the most widely prescribed drugs internationally and is available over the counter in some countries.
Ondansetron is a well tolerated drug with few side effects. Headache, constipation, and dizziness are the most commonly reported side effects associated with its use. There have been no significant drug interactions reported with this drugs use. It is broken down by the hepatic cytochrome P450 system and it has little effect on the metabolism of other drugs broken down by this system; Ondansetron is a serotonin 5-HT3 receptor antagonist used mainly to treat nausea and vomiting following chemotherapy. Its effects are thought to be on both peripheral and central nerves. One part is to reduce the activity of the vagus nerve, which is a nerve that activates the vomiting center in the medulla oblongata, the other is a blockage of serotonin receptors in the chemoreceptor trigger zone. It does not have much effect on vomiting due to motion sickness. This drug does not have any effect on dopamine receptors or muscarinic receptors; A competitive serotonin type 3 receptor antagonist. It is effective in the treatment of nausea and vomiting caused by cytotoxic chemotherapy drugs, including cisplatin, and has reported anxiolytic and neuroleptic properties; Ondansetron (INN) is a serotonin 5-HT3 receptor antagonist used mainly to treat nausea and vomiting following chemotherapy. Its effects are thought to be on both peripheral and central nerves. One part is to reduce the activity of the vagus nerve, which is a nerve that activates the vomiting center in the medulla oblongata, the other is a blockage of serotonin receptors in the chemoreceptor trigger zone. It does not have much effect on vomiting due to motion sickness. This drug does not have any effect on dopamine receptors or muscarinic receptors.
Orlistat is a drug designed to treat obesity. Its primary function is preventing the absorption of fats from the human diet, thereby reducing caloric intake. Orlistat works by inhibiting pancreatic lipase, an enzyme that breaks down triglycerides in the intestine. Without this enzyme, triglycerides from the diet are prevented from being hydrolyzed into absorbable free fatty acids and are excreted undigested.
Oxaprozin is only found in individuals that have used or taken this drug. It is a non-narcotic, non-steroidal anti-inflammatory drug (NSAID), used to relieve the inflammation, swelling, stiffness, and joint pain associated with osteoarthritis and rheumatoid arthritis.Anti-inflammatory effects of Oxaprozin are believed to be due to inhibition of cylooxygenase in platelets which leads to the blockage of prostaglandin synthesis. Antipyretic effects may be due to action on the hypothalamus, resulting in an increased peripheral blood flow, vasodilation, and subsequent heat dissipation. Oxaprozin is a non-selective NSAID, with a cell assay system showing lower COX-2 selectivity implying higher COX-1 selectivity.
Oxazepam is only found in individuals that have used or taken this drug. It is an intermediate-acting benzodiazepine used to treat alcohol withdrawal and anxiety disorders. It is a metabolite of diazepam, prazepam, temazepam, and clorazepate, and has moderate amnesic, anxiolytic, anticonvulsant, hypnotic, sedative, and skeletal muscle relaxant properties compared to other benzodiazepines (Wikipedia). Like other benzodiazepines, oxazepam exerts its anxiolytic effects by potentiating the effect of gamma-aminobutyric acid (GABA) on GABA-A receptors through a cooperative mechanism of action. GABA receptors are ionotropic chloride-linked channel receptors that produce inhibitory postsynaptic potentials. When activated by GABA, the GABA receptor/chloride ionophore complex undergoes a conformational change that allows the passage of chloride ions through the channel. Benzodiazepines are believed to exert their effect by increasing the effect of GABA at its receptor. Benzodiazepine binding increases chloride conductance in the presence of GABA by increasing the frequency at which the channel opens. In contrast, barbiturates increase chloride conductance in the presence of GABA by prolonging the time in which the channel remains open. There are 18 subtypes of the GABA receptor subunits. The &alpha;<sub>2</sub> subunit of the &alpha;<sub>2</sub>&beta;<sub>3</sub>&gamma;<sub>2</sub> receptor complex is thought to mediate anxiolytic effects while the &alpha;<sub>1</sub> subunit of the &alpha;<sub>1</sub>&beta;<sub>2</sub>&gamma;<sub>2</sub> receptor complex is thought to mediate sedative, anticonvulsant, and anterograde amnesia effects.
Oxycodone is only found in individuals that have used or taken this drug. It is a semisynthetic derivative of codeine that acts as a narcotic analgesic more potent and addicting than codeine. [PubChem]Oxycodone acts as a weak agonist at mu, kappa, and delta opioid receptors within the central nervous system (CNS). Oxycodone primarily affects mu-type opioid receptors, which are coupled with G-protein receptors and function as modulators, both positive and negative, of synaptic transmission via G-proteins that activate effector proteins. Binding of the opiate stimulates the exchange of GTP for GDP on the G-protein complex. As the effector system is adenylate cyclase and cAMP located at the inner surface of the plasma membrane, opioids decrease intracellular cAMP by inhibiting adenylate cyclase. Subsequently, the release of nociceptive neurotransmitters such as substance P, GABA, dopamine, acetylcholine, and noradrenaline is inhibited. Opioids such as oxycodone also inhibit the release of vasopressin, somatostatin, insulin, and glucagon. Opioids close N-type voltage-operated calcium channels (kappa-receptor agonist) and open calcium-dependent inwardly rectifying potassium channels (mu and delta receptor agonist). This results in hyperpolarization and reduced neuronal excitability.
An opioid analgesic with actions and uses similar to those of morphine, apart from an absence of cough suppressant activity. It is used in the treatment of moderate to severe pain, including pain in obstetrics. It may also be used as an adjunct to anesthesia. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1092)
A quaternary ammonium anticholinergic agent with peripheral side effects similar to those of atropine. It is used as an adjunct in the treatment of gastric and duodenal ulcer, and to relieve visceral spasms. The drug has also been used in the form of eye drops for mydriatic effect. [PubChem]
4-(Dimethylamino)azobenzene is formerly used as a food dye, use discontinued.Methyl yellow, or C.I. 11020, is a chemical compound which may be used as a pH indicator. In aqueous solution at low pH, methyl yellow appears red. Between pH 2.9 and 4.0, methyl yellow undergoes a transition, to become yellow above pH 4.0. As "butter yellow" the agent had been used as a food additive before its toxicity was recognized (Opie EL). (Wikipedia
p-Anisic acid, also known as 4-anisate or draconic acid, belongs to the class of organic compounds known as p-methoxybenzoic acids and derivatives. These are benzoic acids in which the hydrogen atom at position 4 of the benzene ring is replaced by a methoxy group. p-Anisic acid is a drug. p-Anisic acid exists in all eukaryotes, ranging from yeast to humans. p-Anisic acid is a faint, sweet, and cadaverous tasting compound. Outside of the human body, p-anisic acid has been detected, but not quantified in several different foods, such as anises, cocoa beans, fennels, and german camomiles. This could make p-anisic acid a potential biomarker for the consumption of these foods. It is a white crystalline solid which is insoluble in water, highly soluble in alcohols and soluble in ether, and ethyl acetate. p-Anisic acid has antiseptic properties. It is also used as an intermediate in the preparation of more complex organic compounds. It is generally obtained by the oxidation of anethole or p-methoxyacetophenone. The term "anisic acid" often refers to this form specifically. p-Anisic acid is found naturally in anise.
Pantozol; Pantoprazole (brand names Pantopan in Italy; Protium; Protonix; Pantozol; Pantor; Pantoloc) is a proton pump inhibitor drug used for short-term treatment of erosion and ulceration of the esophagus caused by gastroesophageal reflux disease. Initial treatment is generally of eight weeks' duration, after which another eight week course of treatment may be considered if necessary. It can be used as a maintenance therapy for long term use after initial response is obtained; Pantoprazole is a proton pump inhibitor drug used for short-term treatment of erosion and ulceration of the esophagus caused by gastroesophageal reflux disease. Initial treatment is generally of eight weeks' duration, after which another eight week course of treatment may be considered if necessary. It can be used as a maintenance therapy for long term use after initial response is obtained. Pantoprazole is metabolized in the liver by the cytochrome P450 system. Metabolism mainly consists of demethylation by CYP2C19 followed by sulfation. Another metabolic pathway is oxidation by CYP3A4. Pantoprazole metabolites are not thought to have any pharmacological significance; Protium; Pantor; Pantoloc) is a proton pump inhibitor drug used for short-term treatment of erosion and ulceration of the esophagus caused by gastroesophageal reflux disease. Initial treatment is generally of eight weeks' duration, after which another eight week course of treatment may be considered if necessary. It can be used as a maintenance therapy for long term use after initial response is obtained; Protonix; Pantoprazole (brand names Pantopan in Italy.
Pantothenic acid, also called vitamin B5, is a water-soluble vitamin required to sustain life. Pantothenic acid is needed to form coenzyme-A (CoA), and is thus critical in the metabolism and synthesis of carbohydrates, proteins, and fats. Its name is derived from the Greek pantothen meaning "from everywhere" and small quantities of pantothenic acid are found in nearly every food, with high amounts in whole grain cereals, legumes, eggs, meat, and royal jelly. Pantothenic acid is classified as a member of the secondary alcohols. Secondary alcohols are compounds containing a secondary alcohol functional group, with the general structure HOC(R)(R') (R,R'=alkyl, aryl). Pantothenic acid is considered to be soluble (in water) and acidic.
Papaverine is an alkaloid found in opium but not closely related to the other opium alkaloids in its structure or pharmacological actions. It is a direct-acting smooth muscle relaxant used in the treatment of impotence and as a vasodilator, especially for cerebral vasodilation. The mechanism of its pharmacological actions is not clear, but it apparently can inhibit phosphodiesterases and it may have direct actions on calcium channels. [PubChem].
Paraoxon is an acetylcholinesterase inhibitor. It is an organophosphate oxon, and the active metabolite of the insecticide parathion. It is also used as an opthamological drug against glaucoma. Paraoxon is one of the most potent acetylcholinesterase-inhibiting insecticides available, around 70% as potent as the nerve agent sarin, and so is now rarely used as an insecticide due to the risk of poisoning to humans and other animals. It is easily absorbed through skin, and was used as an assassination weapon by the apartheid-era South African chemical weapons program Project Coast.
Pefloxacin is only found in individuals that have used or taken this drug. It is a synthetic broad-spectrum fluoroquinolone antibacterial agent active against most gram-negative and gram-positive bacteria. [PubChem]The bactericidal action of pefloxacin results from interference with the activity of the bacterial enzymes DNA gyrase and topoisomerase IV, which are needed for the transcription and replication of bacterial DNA. DNA gyrase appears to be the primary quinolone target for gram-negative bacteria. Topoisomerase IV appears to be the preferential target in gram-positive organisms. Interference with these two topoisomerases results in strand breakage of the bacterial chromosome, supercoiling, and resealing. As a result DNA replication and transcription is inhibited.
Penciclovir is only found in individuals that have used or taken this drug. It is a guanine analogue antiviral drug used for the treatment of various herpesvirus infections. It is a nucleoside analogue which exhibits low toxicity and good selectivity. [Wikipedia]Penciclovir has <i>in vitro</i> activity against herpes simplex virus types 1 (HSV-1) and 2 (HSV-2). In cells infected with HSV-1 or HSV-2, viral thymidine kinase phosphorylates penciclovir to a monophosphate form. The monophosphate form of the drug is then converted to penciclovir triphosphate by cellular kinases. The intracellular triphosphate of penciclovir is retained <i>in vitro</i> inside HSV-infected cells for 10-20 hours, compared with 0.7-1 hour for acyclovir. <i>in vitro</i> studies show that penciclovir triphosphate selectively inhibits viral DNA polymerase by competing with deoxyguanosine triphosphate. Inhibition of DNA synthesis of virus-infected cells inhibits viral replication. In cells not infected with HSV, DNA synthesis is unaltered. Resistant mutants of HSV can occur from qualitative changes in viral thymidine kinase or DNA polymerase. The most commonly encountered acyclovir-resistant mutants that are deficient in viral thymidine kinase are also resistant to penciclovir.
Pentoxifylline is only found in individuals that have used or taken this drug. It is a methylxanthine derivative that inhibits phosphodiesterase and affects blood rheology. It improves blood flow by increasing erythrocyte and leukocyte flexibility. It also inhibits platelet aggregation. Pentoxifylline modulates immunologic activity by stimulating cytokine production. [PubChem]Pentoxifylline inhibits erythrocyte phosphodiesterase, resulting in an increase in erythrocyte cAMP activity. Subsequently, the erythrocyte membrane becomes more resistant to deformity. Along with erythrocyte activity, pentoxifylline also decreases blood viscosity by reducing plasma fibrinogen concentrations and increasing fibrinolytic activity. It is also a non selective adenosine receptor antagonist.
Pergolide is a long-acting dopamine agonist approved in 1982 for the treatment of Parkinson's Disease. It is an ergot derivative that acts on the dopamine D2 and D3, alpha2- and alpha1-adrenergic, and 5-hydroxytryptamine (5-HT) receptors. It was indicated as adjunct therapy with levodopa/carbidopa in the symptomatic treatment of parkinsonian syndrome. It was later found that pergolide increased the risk of cardiac valvulopathy. The drug was withdrawn from the US market in March 2007 and from the Canadian market in August 2007.
Phendimetrazine is a weight loss medication. Phendimetrazine is chemically related to amphetamines and is a Schedule III drug under the Convention on Psychotropic Substances. In the United States, phendimetrazine is a Schedule III controlled substance under the Uniform Controlled Substances Act of 1970.
Phendimetrazine is a weight loss medication. Phendimetrazine is chemically related to amphetamines and is a Schedule III drug under the Convention on Psychotropic Substances. In the United States, phendimetrazine is a Schedule III controlled substance under the Uniform Controlled Substances Act of 1970.
Phenelzine is only found in individuals that have used or taken this drug. It is an irreversible non-selective inhibitor of monoamine oxidase. May be used to treat major depressive disorder.Although the exact mechanism of action has not been determined, it appears that the irreversible, nonselective inhibition of MAO by phenelzine relieves depressive symptoms by causing an increase in the levels of serotonin, norepinephrine, and dopamine in the neuron.
2-Phenylethyl acetate, also known as 2-phenethyl acetic acid or benzylcarbinyl acetate, belongs to the class of organic compounds known as benzene and substituted derivatives. These are aromatic compounds containing one monocyclic ring system consisting of benzene. 2-Phenylethyl acetate is a sweet, floral, and fruity tasting compound. 2-Phenylethyl acetate is found, on average, in the highest concentration within ceylon cinnamons and cloves. 2-Phenylethyl acetate has also been detected, but not quantified, in several different foods, such as butternuts, eggplants, turmerics, radish (var.), and pili nuts. This could make 2-phenylethyl acetate a potential biomarker for the consumption of these foods. The acetate ester of 2-phenylethanol.
Phenylacetaldehyde is one important oxidation-related aldehyde. Exposure to styrene gives phenylacetaldehyde as a secondary metabolite. Styrene has been implicated as reproductive toxicant, neurotoxicant, or carcinogen in vivo or in vitro. Phenylacetaldehyde could be formed by diverse thermal reactions during the cooking process together with C8 compounds is identified as a major aroma- active compound in cooked pine mushroom. Phenylacetaldehyde is readily oxidized to phenylacetic acid. Therefore will eventually be hydrolyzed and oxidized to yield phenylacetic acid that will be excreted primarily in the urine in conjugated form. (PMID: 16910727, 7818768, 15606130).
Phenylacetaldehyde is one important oxidation-related aldehyde. Exposure to styrene gives phenylacetaldehyde as a secondary metabolite. Styrene has been implicated as reproductive toxicant, neurotoxicant, or carcinogen in vivo or in vitro. Phenylacetaldehyde could be formed by diverse thermal reactions during the cooking process together with C8 compounds is identified as a major aroma- active compound in cooked pine mushroom. Phenylacetaldehyde is readily oxidized to phenylacetic acid. Therefore will eventually be hydrolyzed and oxidized to yield phenylacetic acid that will be excreted primarily in the urine in conjugated form. (PMID: 16910727, 7818768, 15606130).
Phenylacetylglutamine is a product formed from the conjugation of phenylacetate and glutamine. Technically, it is the amino acid acetylation product of phenylacetate (or phenylbutyrate after beta-oxidation). Phenylacetylglutamine is a normal constituent of human urine, but other mammals such as the dog, cat, rat, monkey, sheep, and horse do not excrete this compound. Phenylacetyl-CoA and L-glutamine react to form phenylacetylglutamine and coenzyme A. The enzyme (glutamine N-acetyl transferase) that catalyzes this reaction has been purified from human liver mitochondria and shown to be a polypeptide species distinct from glycine-N-acyltransferase. Phenylacetylglutamine is a major nitrogenous metabolite that accumulates in uremia (PMID: 2791363, 8972626). It has been shown that over 50% of urine phenylacetylglutamine may be derived from kidney conjugation of free plasma phenylacetic acid and/or from the kidney's preferential filtration of conjugated phenylacetic acid (PMID: 6420430). Phenylacetylglutamine is a microbial metabolite found in Christensenellaceae, Lachnospiraceae and Ruminococcaceae (PMID: 26241311).
Phenylacetylglycine is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acyl glycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13) which is an enzyme that catalyzes the chemical reaction:. acyl-CoA + glycine < -- > CoA + N-acylglycine. Phenylacetylglycine or PAG is a glycine conjugate of phenylacetic acid. Phenylacetic acid may arise from exposure to styrene (plastic) or through the consumption of fruits and vegetables. Phenylacetic acid is used in some perfumes, possessing a honey-like odour in low concentrations, and is also used in penicillin G production. PAG is a putative biomarker of phospholipidosis. Urinary PAG is elevated in animals exhibiting abnormal phospholipid accumulation in many tissues and may thus be useful as a surrogate biomarker for phospholipidosis. (PMID: 15764292) The presence of phenylacetylglycine in urine has been confirmed for dogs, rats and mice. However, the presence of this compound in human urine is controversial. GC-MS studies have not found this compound (PMID: 7492634) while NMR studies claimed to have identified it (PMID: 21167146). It appears that phenylacetylglycine may sometimes be mistaken for phenylacetylglutamine via NMR.
2-Hydroxyphenethylamine, also known as beta-phenethanolamine or 2-amino-1-phenylethanol, belongs to the class of organic compounds known as aralkylamines. These are alkylamines in which the alkyl group is substituted at one carbon atom by an aromatic hydrocarbyl group. It is the simplest member of the class of phenylethanolamines that is 2-aminoethanol bearing a phenyl substituent at the 1-position. 2-Hydroxyphenethylamine exists in all living organisms, ranging from bacteria to humans. 2-Hydroxyphenethylamine ia an amine found in the brain. It may be modulator of sympathetic functions. Its derivatives are adrenergic agonists and antagonists.
2-Hydroxyphenethylamine, also known as beta-phenethanolamine or 2-amino-1-phenylethanol, belongs to the class of organic compounds known as aralkylamines. These are alkylamines in which the alkyl group is substituted at one carbon atom by an aromatic hydrocarbyl group. It is the simplest member of the class of phenylethanolamines that is 2-aminoethanol bearing a phenyl substituent at the 1-position. 2-Hydroxyphenethylamine exists in all living organisms, ranging from bacteria to humans. 2-Hydroxyphenethylamine ia an amine found in the brain. It may be modulator of sympathetic functions. Its derivatives are adrenergic agonists and antagonists.
Phloretin is the aglucone of phlorizin, a plant-derived dihydrochalcone phytochemical reported to promote potent antioxidative activities in peroxynitrite scavenging and the inhibition of lipid peroxidation. Phloretin, which is present in apples, pears and tomatoes, has been found to inhibit the growth of several cancer cells and induce apoptosis of B16 melanoma and HL60 human leukemia cells. Phloretin also inhibits HT-29 cell growth by inducing apoptosis, which may be mediated through changes in mitochondrial membrane permeability and activation of the caspase pathways. Phloretin is a well-known inhibitor of eukaryotic urea transporters, blocks VacA-mediated urea and ion transport (PMID:18158826, 11560962, 18063724, 15671209, 12083758). Phloretin is a biomarker for the consumption of apples. Phloretin has been found to be a metabolite of Escherichia (PMID:23542617).
Phloroglucinol is a benzenetriol. It is an organic compound that is used in the synthesis of pharmaceuticals and explosives. This molecule exists in two forms, or tautomers, 1,3,5-trihydroxybenzene, which has phenol-like, and 1,3,5-cyclohexanetrione (phloroglucin), which has ketone-like character. These two tautomers are in equilibrium. Phloroglucinol is a useful intermediate because it is polyfunctional. 1,3,5-Trihydroxybenzene has been found to be a metabolite in Pseudomonas (PMID: 15826166).
Phosphorylcholine, also known as choline phosphate or CHOP, belongs to the class of organic compounds known as phosphocholines. Phosphocholines are compounds containing a [2-(trimethylazaniumyl)ethoxy]phosphonic acid or derivative. The phosphate of choline, and the parent compound of the phosphorylcholine family. Phosphorylcholine exists in all living species, ranging from bacteria to humans. Within humans, phosphorylcholine participates in a number of enzymatic reactions. In particular, phosphorylcholine can be converted into choline through its interaction with the enzyme phosphoethanolamine/phosphocholine phosphatase. In addition, phosphorylcholine can be converted into CDP-choline; which is mediated by the enzyme choline-phosphate cytidylyltransferase a. In humans, phosphorylcholine is involved in phospholipid biosynthesis. Outside of the human body, phosphorylcholine has been detected, but not quantified in several different foods, such as barley, pak choy, black radish, saskatoon berries, and acorns.
Phosphoenolpyruvate (PEP) is an important chemical compound in biochemistry. It has a high energy phosphate bond, and is involved in glycolysis and gluconeogenesis. In glycolysis, PEP is formed by the action of the enzyme enolase on 2-phosphoglycerate. Metabolism of PEP to pyruvate by pyruvate kinase (PK) generates 1 molecule of adenosine triphosphate (ATP) via substrate-level phosphorylation. ATP is one of the major currencies of chemical energy within cells. In gluconeogenesis, PEP is formed from the decarboxylation of oxaloacetate and hydrolysis of 1 guanosine triphosphate molecule. This reaction is catalyzed by the enzyme phosphoenolpyruvate carboxykinase (PEPCK). This reaction is a rate-limiting step in gluconeogenesis. (wikipedia).
Phosphonoacetate, also known as fosfonet or phosphonacetic acid, belongs to the class of organic compounds known as organic phosphonic acids. These are organic compounds containing phosphonic acid. Phosphonoacetate exists in all living organisms, ranging from bacteria to humans.
Phthalic acid is an aromatic dicarboxylic acid, with formula C6H4(COOH)2. Phthalic acid is used mainly in the form of the anhydride to produce other chemicals such as dyes, perfumes, saccharin, phthalates and many other useful products. Phthalic acid, when found in tissues or biofluids arises from exposure to these phthalate products. Phthalate is an environmental chemical of heightened public concern because reports of its potential risk to male reproductive health (PMID 16804814), being significantly associated with reduced sperm concentration to pesticide concentration in men's urine (PMID 16804812). Within the reproductive tract, the male is exquisitely vulnerable to the effects of anti-androgens during development due the reliance on the synthesis and action of androgens for the masculinization of the male reproductive tract. The ability of phthalates to suppress androgen synthesis during development and to induce testicular dysgenesis together with cryptorchidism and hypospadias has raised considerable concern. (PMID 15016950).
A cholinesterase inhibitor that is rapidly absorbed through membranes. It can be applied topically to the conjunctiva. It also can cross the blood-brain barrier and is used when central nervous system effects are desired, as in the treatment of severe anticholinergic toxicity. [PubChem]
Phytosphingosine is a phospholipid. Phospholipids are a class of lipids and a major component of all biological membranes; sphingolipid metabolites, such as sphingosine and ceramide, are highly bioactive compounds and are involved in diverse cell processes, including cell-cell interaction, cell proliferation, differentiation, and apoptosis. Phytosphingosine is also one of the most widely distributed natural sphingoid bases, which is abundant in fungi and plants, and also found in animals including humans. Phytosphingosine is structurally similar to sphingosine; phytosphingosine possesses a hydroxyl group at C-4 of the sphingoid long-chain base. The physiological roles of phytosphingosine are largely unknown. Phytosphingosine induces apoptosis in human T-cell lymphoma and non-small cell lung cancer cells, and induces caspase-independent cytochrome c release from mitochondria. In the presence of caspase inhibitors, phytosphingosine-induced apoptosis is almost completely suppressed, suggesting that phytosphingosine-induced apoptosis is largely dependent on caspase activities. (PMID: 12576463, 12531554, 8046331, 8048941,8706124).
Pilocarpine is only found in individuals that have used or taken this drug. It is a slowly hydrolyzed muscarinic agonist with no nicotinic effects. Pilocarpine is used as a miotic and in the treatment of glaucoma. [PubChem]Pilocarpine is a cholinergic parasympathomimetic agent. It increase secretion by the exocrine glands, and produces contraction of the iris sphincter muscle and ciliary muscle (when given topically to the eyes) by mainly stimulating muscarinic receptors.
Pioglitazone is used for the treatment of diabetes mellitus type 2. Pioglitazone selectively stimulates nuclear receptor peroxisone proliferator-activated receptor gamma (PPAR-gamma). It modulates the transcription of the insulin-sensitive genes involved in the control of glucose and lipid metabolism in the lipidic, muscular tissues and in the liver.
Pipecolic acid is a metabolite of lysine found in human physiological fluids such as urine, plasma and CSF. However, it is uncertain if pipecolic acid originates directly from food intake or from mammalian or intestinal bacterial enzyme metabolism. Recent studies suggest that plasma pipecolic acid, particularly the D-isomer, originates mainly from the catabolism of dietary lysine by intestinal bacteria rather than by direct food intake. In classic Zellweger syndrome (a cerebro-hepato-renal genetic disorder, OMIM 214100) pipecolic acid accumulate in the plasma of the patients. It is known that plasma pipecolic acid levels are also elevated in patients with chronic liver diseases. Pipecolic acid is moderately elevated in patients with pyridoxine-dependent seizures and might therefore be a possible biochemical marker for selecting candidates for pyridoxine therapy (Plecko et al 2000). Pipecolic acid was also elevated in CSF in these vitamin B6-responsive patients (PMID 12705501). Pipecolic acid is found to be associated with adrenoleukodystrophy, infantile Refsum disease, and peroxisomal biogenesis defect, which are also inborn errors of metabolism. Pipecolic acid is a biomarker for the consumption of dried and cooked beans.
Piperine, also known as fema 2909, belongs to the class of organic compounds known as alkaloids and derivatives. These are naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids. In addition to carbon, hydrogen and nitrogen, alkaloids may also contain oxygen, sulfur and more rarely other elements such as chlorine, bromine, and phosphorus. Piperine is a pepper tasting compound. Piperine is found in the highest concentration within pepper (Piper nigrum) and many other Piper species. Piperine has also been detected, but not quantified, in dills and herbs and spices.  Piperine is responsible for the hot taste of pepper. Piperine has been used in trials studying the treatment of Multiple Myeloma and Deglutition Disorders. It is used to impart pungent taste to brandy.
Piroxicam is only found in individuals that have used or taken this drug. It is a cyclooxygenase inhibiting, non-steroidal anti-inflammatory agent (NSAID) that is well established in treating rheumatoid arthritis and osteoarthritis and used for musculoskeletal disorders, dysmenorrhea, and postoperative pain. Its long half-life enables it to be administered once daily. [PubChem]The antiinflammatory effect of Piroxicam may result from the reversible inhibition of cyclooxygenase, causing the peripheral inhibition of prostaglandin synthesis. The prostaglandins are produced by an enzyme called Cox-1. Piroxicam blocks the Cox-1 enzyme, resulting into the disruption of production of prostaglandins. Piroxicam also inhibits the migration of leukocytes into sites of inflammation and prevents the formation of thromboxane A2, an aggregating agent, by the platelets.
Most statins are metabolised in part by one or more hepatic cytochrome P450 enzymes, leading to an increased potential for drug interactions and problems with certain foods (such as grapefruit juice). Pitavastatin appears to be a substrate of CYP2C9, and not CYP3A4 (which is a common source of interactions in other statins). As a result, pitavastatin is less likely to interact with drugs that are metabolized via CYP3A4, which might be important for elderly patients who need to take multiple medicines. Pitavastatin (usually as a calcium salt) is a member of the medication class of statins, marketed in the United States under the trade name Livalo. Like other statins, it is an inhibitor of HMG-CoA reductase, the enzyme that catalyses the first step of cholesterol synthesis. It has been available in Japan since 2003, and is being marketed under licence in South Korea and in India. It is likely that pitavastatin will be approved for use in hypercholesterolaemia (elevated levels of cholesterol in the blood) and for the prevention of cardiovascular disease outside South and Southeast Asia as well.
Pramipexole is a medication indicated for treating Parkinson's disease and restless legs syndrome (RLS). It is also sometimes used off-label as a treatment for cluster headache or to counteract the problems with low libido experienced by some users of SSRI antidepressant drugs. Pramipexole has shown robust effects on pilot studies in bipolar disorder. Pramipexole is classified as a non-ergoline dopamine agonist.
Prazepam is only found in individuals that have used or taken this drug. It is a benzodiazepine that is used in the treatment of anxiety disorders. It is a schedule IV drug in the U.S. Prazepam is believed to stimulate GABA receptors in the ascending reticular activating system. Since GABA is inhibitory, receptor stimulation increases inhibition and blocks both cortical and limbic arousal following stimulation of the brain stem reticular formation.
Prazosin is a selective &alpha;-<sub>1</sub>-adrenergic receptor antagonist used to treat hypertension. It has also been used to decrease urinary obstruction and relieve symptoms associated with symptomatic benign prostatic hyperplasia. &alpha;<sub>1</sub>-Receptors mediate contraction and hypertrophic growth of smooth muscle cells. Antagonism of these receptors leads to smooth muscle relaxation in the peripheral vasculature and prostate gland. Prazosin has also been used in conjunction with cardiac glycosides and diuretics in the management of severe congestive heart failure. It has also been used alone or in combination with &beta;-blockers in the preoperative management of signs and symptoms of pheochromocytoma.
Prochlorperazine is only found in individuals that have used or taken this drug. It is a phenothiazine antipsychotic used principally in the treatment of nausea; vomiting; and vertigo. It is more likely than chlorpromazine to cause extrapyramidal disorders. (From Martindale, The Extra Pharmacopoeia, 30th ed, p612)The mechanism of action of prochlorperazine has not been fully determined, but may be primarily related to its antidopaminergic effects. Prochlorperazine blocks the D2 somatodendritic autoreceptor, resulting in the blockade of postsynaptic dopamine receptors in the mesolimbic system and an increased dopamine turnover. Prochlorperazine also has anti-emetic effects, which can be attributed to dopamine blockade in the chemoreceptor trigger zone. Prochlorperazine also blocks anticholinergic and alpha-adrenergic receptors, the blockade of alpha(1)-adrenergic receptors resulting in sedation, muscle relaxation, and hypotension.
The major progestational steroid that is secreted primarily by the corpus luteum and the placenta. Progesterone acts on the uterus, the mammary glands and the brain. It is required in embryo implantation, pregnancy maintenance, and the development of mammary tissue for milk production. Progesterone, converted from pregnenolone, also serves as an intermediate in the biosynthesis of gonadal steroid hormones and adrenal corticosteroids. Progesterone is a C-21 steroid hormone involved in the female menstrual cycle, pregnancy (supports gestation) and embryogenesis of humans and other species. Progesterone belongs to a class of hormones called progestagens, and is the major naturally occurring human progestagen. During implantation and gestation, progesterone appears to decrease the maternal immune response to allow for the acceptance of the pregnancy. Progesterone decreases contractility of the uterine smooth muscle. The fetus metabolizes placental progesterone in the production of adrenal mineralo- and glucosteroids. A drop in progesterone levels is possibly one step that facilitates the onset of labor. In addition progesterone inhibits lactation during pregnancy. The fall in progesterone levels following delivery is one of the triggers for milk production. Progesterone is found to be associated with pregnene hydroxylation deficiency, which is an inborn error of metabolism.
Prolylhydroxyproline is a dipeptide. Prolylhydroxyproline is a marker of bone collagen degradation, showing high sensitivity for the diagnosis of osteoporosis. Prolylhydroxyproline has been suggested as a possible alternative to hydroxyproline determination in bone resorption studies. Prolylhydroxyproline is one of the iminodipeptides present in the urine of patients with prolidase deficiency. Prolidase (X-Pro dipeptidase EC 3.4.13.9) splits iminodipeptides containing C-terminal proline or hydroxyproline (X-Pro or X-Hyp) to X+Pro or X+Hyp. Prolidase deficiency is a rare autosomal recessive disease characterized by chronic ulcerative dermatitis and mental retardation. These patients excrete large amounts of iminodipeptides containing C-terminal proline in the urine due to hereditary prolidase deficiency (PMID: 12636053, 11863289, 2387877, 1874885, 9586797).
Purine, also known as purine base or 1H-purine, belongs to the class of organic compounds known as purines and purine derivatives. These are aromatic heterocyclic compounds containing a purine moiety, which is formed a pyrimidine-ring ring fused to an imidazole ring. Two of the bases in nucleic acids, adenine and guanine, are purines. Purines from food (or from tissue turnover) are metabolised by several enzymes, including xanthine oxidase, into uric acid. Purine exists in all living species, ranging from bacteria to humans. High levels of uric acid can predispose to gout when the acid crystalises in joints; this phenomenon only happens in humans and some animal species (e.g. dogs) that lack an intrinsic uricase enzyme that can further degrade uric acid. In humans, purine is involved in thioguanine action pathway. Outside of the human body, purine is found, on average, in the highest concentration within cocoa beans. Purine has also been detected, but not quantified in several different foods, such as rapinis, plains prickly pears, blackcurrants, radish, and parsley. This could make purine a potential biomarker for the consumption of these foods. Purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring.
Pyridine is a clear liquid with an odor that is sour, putrid, and fish-like. It is a relatively simple heterocyclic aromatic organic compound that is structurally related to benzene, with one CH group in the six-membered ring replaced by a nitrogen atom. Pyridine is obtained from crude coal tar or is synthesized from acetaldehyde, formaldehyde and ammonia. Pyridine is often used as a denaturant for antifreeze mixtures, for ethyl alcohol, for fungicides, and as a dyeing aid for textiles. It is a harmful substance if inhaled, ingested or absorbed through the skin. In particular, it is known to reduce male fertility and is considered carcinogenic. Common symptoms of acute exposure to pyridine include: headache, coughing, asthmatic breathing, laryngitis, nausea and vomiting. -- Wikipedia.
Pyridoxal phosphate, also known as PLP, pyridoxal 5'-phosphate or P5P, is the active form of vitamin B6. It is a coenzyme in a variety of enzymatic reactions. Pyridoxal 5'-phosphate belongs to the class of organic compounds known as pyridoxals and derivatives. Pyridoxals and derivatives are compounds containing a pyridoxal moiety, which consists of a pyridine ring substituted at positions 2,3,4, and 5 by a methyl group, a hydroxyl group, a carbaldehyde group, and a hydroxymethyl group, respectively. Pyridoxal 5'-phosphate is a drug which is used for nutritional supplementation and for treating dietary shortage or imbalance. Pyridoxal 5'-phosphate exists in all living species, ranging from bacteria to humans. In humans, pyridoxal 5'-phosphate is involved in glycine and serine metabolism. Outside of the human body, pyridoxal 5'-phosphate is found, on average, in the highest concentration within cow milk. Pyridoxal 5'-phosphate has also been detected, but not quantified in several different foods, such as soursops, italian sweet red peppers, muscadine grapes, european plums, and blackcurrants. Pyridoxal 5'-phosphate, with regard to humans, has been found to be associated with several diseases such as epilepsy, early-onset, vitamin B6-dependent, odontohypophosphatasia, pyridoxamine 5-prime-phosphate oxidase deficiency, and hypophosphatasia. Pyridoxal 5'-phosphate has also been linked to the inborn metabolic disorder celiac disease.
Pyridoxine, also known vitamin B6, is commonly found in food and is used as a dietary supplement. Pyridoxine is an essential nutrient, meaning the body cannot synthesize it, and it must be obtained from the diet. Sources in the diet include fruit, vegetables, and grain. Although pyridoxine and vitamin B6 are still frequently used as synonyms, especially by medical researchers, this practice is sometimes misleading (PMID: 2192605). Technically, pyridoxine is one of the compounds that can be called vitamin B6 or it is a member of the family of B6 vitamins. Healthy human blood levels of pyridoxine are 2.1 - 21.7 ng/mL. Pyridoxine is readily converted to pyridoxal phosphate which is a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids and aminolevulinic acid. Pyridoxine assists in the balancing of sodium and potassium as well as promoting red blood cell production. Therefore pyridoxine is required by the body to make amino acids, carbohydrates, and lipids. It is linked to cancer immunity and helps fight the formation of homocysteine. It has been suggested that pyridoxine might help children with learning difficulties, and may also prevent dandruff, eczema, and psoriasis. In addition, pyridoxine can help balance hormonal changes in women and aid in immune system. Lack of pyridoxine may cause anemia, nerve damage, seizures, skin problems, and sores in the mouth (Wikipedia). Deficiency of pyridoxine, though rare because of widespread distribution in foods, leads to the development of peripheral neuritis in adults and affects the central nervous system in children (DOSE - 3rd edition). As a supplement pyridoxine is used to treat and prevent pyridoxine deficiency, sideroblastic anaemia, pyridoxine-dependent epilepsy, certain metabolic disorders, problems from isoniazid, and certain types of mushroom poisoning. Pyridoxine in combination with doxylamine is used as a treatment for morning sickness in pregnant women.
Rabeprazole is a proton pump inhibitor sold (as its sodium salt) under the brand names Aciphex and Pariet (distributed by Janssen-Cilag); Rabeprazole is a proton pump inhibitor sold (as its sodium salt) and it is used in the treatment of gastric ulcers and GERD (or heartburn). It is taken once a day along with a full glass of water (preferable 30 min before breakfast).
Raltitrexed is only found in individuals that have used or taken this drug. It is a chemotherapy drug manufactured AstraZeneca Company, is an antimetabolite used in chemotherapy. It is an inhibitor of thymidylate synthase.Raltitrexed is an antineoplastic Agents and folic acid antagonists. Raltitrexed inhibits thymidylate synthase (TS) leading to DNA fragmentation and cell death. It is transported into cells via a reduced folate carrier. Inside the cell Raltitrexed is extensively polyglutamated, which enhances thymidylate synthase inhibitory power and duration. Inhibition of this enzyme results in decreased synthesis of thymidine triphosphate which is required for DNA synthesis.
Ramipril is a prodrug belonging to the angiotensin-converting enzyme (ACE) inhibitor class of medications. It is metabolized to ramiprilat in the liver and, to a lesser extent, kidneys. Ramiprilat is a potent, competitive inhibitor of ACE, the enzyme responsible for the conversion of angiotensin I (ATI) to angiotensin II (ATII). ATII regulates blood pressure and is a key component of the renin-angiotensin-aldosterone system (RAAS). Ramipril may be used in the treatment of hypertension, congestive heart failure, nephropathy, and to reduce the rate of death, myocardial infarction and stroke in individuals at high risk of cardiovascular events.
Ranitidine (CAS: 66357-35-5) is a non-imidazole blocker of histamine receptors that mediate gastric secretion (H2 receptors). It is used to treat gastrointestinal ulcers (PubChem). Ranitidine is a histamine H2-receptor antagonist that inhibits stomach acid production and is commonly used in the treatment of peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD). It is currently marketed by GlaxoSmithKline under the trade name Zantac (Wikipedia).
Ranolazine is only found in individuals that have used or taken this drug. It is an antianginal medication. On January 31, 2006, ranolazine was approved for use in the United States by the FDA for the treatment of chronic angina. [Wikipedia]The mechanism of action of ranolazine is unknown. It does not increase the rate-pressure product, a measure of myocardial work, at maximal exercise. In vitro studies suggest that ranolazine is a P-gp inhibitor. Ranolazine is believed to have its effects via altering the trans-cellular late sodium current. It is by altering the intracellular sodium level that ranolazine affects the sodium-dependent calcium channels during myocardial ischemia. Thus, ranolazine indirectly prevents the calcium overload that causes cardiac ischemia.
Repaglinide is an oral antihyperglycemic agent used for the treatment of non-insulin-dependent diabetes mellitus (NIDDM). It belongs to the meglitinide class of short-acting insulin secretagogues, which act by binding to cells of the pancreas to stimulate insulin release. Repaglinide induces an early insulin response to meals decreasing postprandial blood glucose levels. It should only be taken with meals and meal-time doses should be skipped with any skipped meal. Approximately one month of therapy is required before a decrease in fasting blood glucose is seen. Meglitnides may have a neutral effect on weight or cause a slight increase in weight. The average weight gain caused by meglitinides appears to be lower than that caused by sulfonylureas and insulin and appears to occur only in those naive to oral antidiabetic agents. Due to their mechanism of action, meglitinides may cause hypoglycemia although the risk is thought to be lower than that of sulfonylureas since their action is dependent on the presence of glucose. In addition to reducing postprandial and fasting blood glucose, meglitnides have been shown to decrease glycosylated hemoglobin (HbA1c) levels, which are reflective of the last 8-10 weeks of glucose control. Meglitinides appear to be more effective at lowering postprandial blood glucose than metformin, sulfonylureas and thiazolidinediones. Repaglinide is extensively metabolized in the liver and excreted in bile. Repaglinide metabolites do not possess appreciable hypoglycemic activity. Approximately 90% of a single orally administered dose is eliminated in feces and 8% in urine.
Resveratrol is a polyphenolic phytoalexin. It is also classified as a stilbenoid, a derivate of stilbene, and is produced in plants with the help of the enzyme stilbene synthase. The levels of resveratrol found in food vary greatly. Red wine contains between 0.2 and 5.8 mg/L depending on the grape variety, while white wine has much less. The reason for this difference is that red wine is fermented with grape skins, allowing the wine to absorb the resveratrol, whereas white wine is fermented after the skin has been removed. Resveratrol is also sold as a nutritional supplement. A number of beneficial health effects, such as anti-cancer, antiviral, neuroprotective, anti-aging, anti-inflammatory, and life-prolonging effects have been reported for resveratrol. The fact that resveratrol is found in the skin of red grapes and as a constituent of red wine may explain the "French paradox". This paradox is based on the observation that the incidence of coronary heart disease is relatively low in southern France despite high dietary intake of saturated fats. Resveratrol is thought to achieve these cardioprotective effects by a number of different routes: (1) inhibition of vascular cell adhesion molecule expression; (2) inhibition of vascular smooth muscle cell proliferation; (3) stimulation of endothelial nitric oxide synthase (eNOS) activity; (4) inhibition of platelet aggregation; and (5) inhibition of LDL peroxidation (PMID: 17875315, 14676260, 9678525). Resveratrol is a biomarker for the consumption of grapes and raisins.
all-trans-Retinoic acid is an isomer of retinoic acid, the oxidized form of vitamin A. Retinoic acid functions in determining position along embryonic anterior/posterior axis in chordates. It acts through Hox genes, which ultimately controls anterior/posterior patterning in early developmental stages (PMID:17495912). It is an important regulator of gene expression during growth and development, and in neoplasms. As a drug, all-trans-retinoic acid is known as tretinoin. Tretinoin is derived from maternal vitamin A and is essential for normal growth and embryonic development. An excess of tretinoin can be teratogenic. Tretinoin is used in the treatment of psoriasis, acne vulgaris, and several other skin diseases. It has also been approved for use in promyelocytic leukemia (leukemia, promyelocytic, acute).
Riboflavin or vitamin B2 is an easily absorbed, water-soluble micronutrient with a key role in maintaining human health. Like the other B vitamins, it supports energy production by aiding in the metabolizing of fats, carbohydrates, and proteins. Vitamin B2 is also required for red blood cell formation and respiration, antibody production, and for regulating human growth and reproduction. It is essential for healthy skin, nails, hair growth and general good health, including regulating thyroid activity. Riboflavin is found in milk, eggs, malted barley, liver, kidney, heart, and leafy vegetables. Riboflavin is yellow or orange-yellow in color and in addition to being used as a food coloring it is also used to fortify some foods. It can be found in baby foods, breakfast cereals, sauces, processed cheese, fruit drinks and vitamin-enriched milk products. The richest natural source is yeast. It occurs in the free form only in the retina of the eye, in whey, and in urine; its principal forms in tissues and cells are as flavin mononucleotide and flavin adenine dinucleotide.
Riluzole is only found in individuals that have used or taken this drug. It is a glutamate antagonist (receptors, glutamate) used as an anticonvulsant (anticonvulsants) and to prolong the survival of patients with amyotrophic lateral sclerosis. [PubChem]The mode of action of riluzole is unknown. Its pharmacological properties include the following, some of which may be related to its effect: 1) an inhibitory effect on glutamate release (activation of glutamate reuptake), 2) inactivation of voltage-dependent sodium channels, and 3) ability to interfere with intracellular events that follow transmitter binding at excitatory amino acid receptors.
Risperidone is an atypical antipsychotic medication approved in 1993. It is most often used to treat delusional psychosis (including schizophrenia), but risperidone (like other atypical antipsychotics) is also used to treat some forms of bipolar disorder, psychotic depression and Tourette syndrome. Generally lower doses are used for autistic spectrum disorders than are used for schizophrenia and other forms of psychosis; Risperidone is a very strong dopamine blocker (antagonist); Risperidone is a very strong dopamine blocker (antagonist); i.e., it inhibits functioning of postsynaptic dopamine receptors. An anxiolytic agent and a serotonin receptor agonist belonging to the azaspirodecanedione class of compounds. Its structure is unrelated to those of the benzodiazepines, but it has an efficacy comparable to diazepam; i.e., it inhibits functioning of postsynaptic dopamine receptors. Risperidone (Belivon, Rispen, Risperdal; in the United States) is an atypical antipsychotic medication. It was approved by the United States Food and Drug Administration (FDA) in 1993. It is most often used to treat delusional psychosis (including schizophrenia), but risperidone (like other atypical antipsychotics) is also used to treat some forms of bipolar disorder, psychotic depression and Tourette syndrome; risperidone has received approval from the Food and Drug Administration (FDA) for symptomatic treatment of irritability in autistic children and adolescents. Risperidone is now the most commonly prescribed antipsychotic medication in the United States.
Ritonavir is only found in individuals that have used or taken this drug. It is an HIV protease inhibitor that works by interfering with the reproductive cycle of HIV. [PubChem]Ritonavir inhibits the HIV viral proteinase enzyme which prevents cleavage of the gag-pol polyprotein, resulting in noninfectious, immature viral particles.
Rizatriptan is only found in individuals that have used or taken this drug. It is a triptan drug used for the treatment of migraine headaches. It is a selective 5-hydroxytryptamine1 receptor subtype agonist.Three distinct pharmacological actions have been implicated in the antimigraine effect of the triptans: (1) stimulation of presynaptic 5-HT1D receptors, which serves to inhibit both dural vasodilation and inflammation; (2) direct inhibition of trigeminal nuclei cell excitability via 5-HT1B/1D receptor agonism in the brainstem and (3) vasoconstriction of meningeal, dural, cerebral or pial vessels as a result of vascular 5-HT1B receptor agonism.
Ropivacaine is only found in individuals that have used or taken this drug. It is a local anaesthetic drug belonging to the amino amide group. The name ropivacaine refers to both the racemate and the marketed S-enantiomer. Ropivacaine hydrochloride is commonly marketed by AstraZeneca under the trade name Naropin. [Wikipedia]Local anesthetics such as Ropivacaine block the generation and the conduction of nerve impulses, presumably by increasing the threshold for electrical excitation in the nerve, by slowing the propagation of the nerve impulse, and by reducing the rate of rise of the action potential. Specifically, they block the sodium-channel and decrease chances of depolarization and consequent action potentials. In general, the progression of anesthesia is related to the diameter, myelination and conduction velocity of affected nerve fibers.
Rosiglitazone is an anti-diabetic drug from the thiazolidinedione class. Like other thiazolidinediones, its mechanism of action is by activation of the intracellular receptor class of the peroxisome proliferator-activated receptors (PPARs), specifically PPAR-gamma. Rosiglitazone is a pure ligand of PPAR-gamma, and has no PPAR-alpha-binding action. Apart from its effect on insulin resistance, it appears to have an anti-inflammatory effect: nuclear factor kappa-B (NF&#954;B) levels fall and inhibitor (I&#954;B) levels increase in patients on rosiglitazone (Mohanty et al). It increases glyceroneogenesis and reduces the release of free fatty acids from adipocytes; Rosiglitazone is an anti-diabetic drug from the thiazolidinedione class. It is being marketed as Avandia by the pharmaceutical company GlaxoSmithKline, both as a standalone preparation and in combination with metformin (Avandamet). Another combination drug approved by the FDA is Avandaryl (with glimepiride); Like other thiazolidinediones, its mechanism of action is by activation of the intracellular receptor class of the peroxisome proliferator-activated receptors (PPARs), specifically PPAR-gamma. Rosiglitazone is a pure ligand of PPAR-gamma, and has no PPAR-alpha binding action. Apart from its effect on insulin resistance, it appears to have an anti-inflammatory effect: nuclear factor kappa-B (NFkB) levels fall and inhibitor (IkB) levels increase in patients on rosiglitazone (Mohanty et al). It increases glyceroneogenesis and reduces the release of free fatty acids from adipocytes.
Roxatidine acetate is only found in individuals that have used or taken this drug. It is a specific and competitive H2 receptor antagonist. It is currently approved in South Africa under the tradename Roxit.The H2 antagonists are competitive inhibitors of histamine at the parietal cell H2 receptor. They suppress the normal secretion of acid by parietal cells and the meal-stimulated secretion of acid. They accomplish this by two mechanisms: histamine released by ECL cells in the stomach is blocked from binding on parietal cell H2 receptors which stimulate acid secretion, and other substances that promote acid secretion (such as gastrin and acetylcholine) have a reduced effect on parietal cells when the H2 receptors are blocked.
Rufloxacin belongs to the family of Phenylpiperazines. These are compounds containing a phenylpiperazine skeleton, which consists of a piperazine bound to a phenyl group.
Rutin is a flavonoid known to have a variety of biological activities including antiallergic, anti-inflammatory, antiproliferative, and anticarcinogenic properties. A large number of flavonoids, mostly O-glycosides, are polyphenolic compounds of natural origin that are present in most fruits and vegetables. The average intake of the compounds by humans on a normal diet is more than 1 g per day. Although flavonoids are devoid of classical nutritional value, they are increasingly viewed as beneficial dietary components that act as potential protectors against human diseases such as coronary heart disease, cancers, and inflammatory bowel disease. Rutin acts as a quercetin deliverer to the large intestine; moreover, quercetin is extensively metabolized in the large intestine, which suggests that quercetin liberated from rutin and/or its colonic metabolites may play a role. Rutin's anti-inflammatory actions are mediated through a molecular mechanism that underlies the quercetin-mediated therapeutic effects: quercetin-mediated inhibition of tumor necrosis factor-alpha (TNF-alpha)-induced nuclear factor kappa B (NFkB) activation. TNF-alpha-induced NFkB activity plays a central role in the production of pro-inflammatory mediators involved in progression of gut inflammation. (PMID:16132362).
Salmeterol is only found in individuals that have used or taken this drug. It is a long-acting beta2-adrenergic receptor agonist drug that is currently prescribed for the treatment of asthma and chronic obstructive pulmonary disease COPD. Salmeterol's long, lipophilic side chain binds to exosites near beta(2)-receptors in the lungs and on bronchiolar smooth muscle, allowing the active portion of the molecule to remain at the receptor site, continually binding and releasing. Beta(2)-receptor stimulation in the lung causes relaxation of bronchial smooth muscle, bronchodilation, and increased bronchial airflow.
Sarcosine is the N-methyl derivative of glycine. Sarcosine is metabolized to glycine by the enzyme sarcosine dehydrogenase, while glycine-N-methyl transferase generates sarcosine from glycine. Sarcosine is a natural amino acid found in muscles and other body tissues. In the laboratory it may be synthesized from chloroacetic acid and methylamine. Sarcosine is naturally found in the metabolism of choline to glycine. Sarcosine is sweet to the taste and dissolves in water. It is used in manufacturing biodegradable surfactants and toothpastes as well as in other applications. Sarcosine is ubiquitous in biological materials and is present in such foods as egg yolks, turkey, ham, vegetables, legumes, etc. Sarcosine is formed from dietary intake of choline and from the metabolism of methionine, and is rapidly degraded to glycine. Sarcosine has no known toxicity, as evidenced by the lack of phenotypic manifestations of sarcosinemia, an inborn error of sarcosine metabolism. Sarcosinemia can result from severe folate deficiency because of the folate requirement for the conversion of sarcosine to glycine (Wikipedia). Sarcosine has recently been identified as a biomarker for invasive prostate cancer. It was found to be greatly increased during prostate cancer progression to metastasis and could be detected in urine. Sarcosine levels were also increased in invasive prostate cancer cell lines relative to benign prostate epithelial cells (PMID: 19212411).
Scopoletin is found in anise. Scopoletin is isolated from Angelica acutiloba (Dong Dang Gui
Sertraline is a selective serotonin uptake inhibitor that is used in the treatment of depression. Sertraline hydrochloride (also labeled under numerous brand names: Zoloft, Sertralin, Lustral, Apo-Sertral, Asentra, Gladem, Serlift, Stimuloton, Xydep, Serlain, Concorz) is an orally administered antidepressant of the selective serotonin reuptake inhibitor (SSRI) type. It was first approved by the Food and Drug Administration (FDA) in 1991. Sertraline is an odorless, white, sparingly soluble crystalline solid. The minimum effective dose is usually 50 mg per day (it can be still effective at 25 mg or 37.5 mg), but lower doses may be used in the initial weeks of treatment to acclimate the patient's body, especially the liver, to the drug and to minimize the severity of any side effects. Patients who do not experience relief of symptoms at 50 mg a day may have their dose increased, up to 200 mg a day. Sertraline (HCl) is used medically mainly to treat the symptoms of depression and anxiety. It is also prescribed for the treatment of obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), premenstrual dysphoric disorder (PMDD), panic disorder (PD) and social phobia/social anxiety disorder. A study has shown that sertraline is an effective treatment for impulsive aggressive behavior in personality disordered patients.
Sibutramine (trade name Meridia in the USA, Reductil in Europe and other countries), usually as sibutramide hydrochloride monohydrate, is an orally administered agent for the treatment of obesity. It is a centrally acting stimulant chemically related to amphetamines. Sibutramine is classified as a Schedule IV controlled substance in the United States. In October 2010, Sibutramine was withdrawn from Canadian and U.S. markets due to concerns that the drug increases the risk of heart attack and stroke in patients with a history of heart disease.
Sinapic acid, also known as sinapinate, belongs to the class of organic compounds known as hydroxycinnamic acids. Hydroxycinnamic acids are compounds containing an cinnamic acid where the benzene ring is hydroxylated. Sinapic acid has been detected, but not quantified, in several different foods, such as strawberry guava, purple lavers, common verbena, ryes, and lupines. This could make sinapic acid a potential biomarker for the consumption of these foods. A sinapic acid in which the double bond has trans-configuration.
Sotalol is only found in individuals that have used or taken this drug. It is an adrenergic beta-antagonist that is used in the treatment of life-threatening arrhythmias (PubChem). Sotalol has both beta-adrenoreceptor blocking (Vaughan Williams Class I) and cardiac action potential duration prolongation (Vaughan Williams Class I) antiarrhythmic properties. Sotalol is a racemic mixture of d- and l-sotalol. Both isomers have similar Class I antiarrhythmic effects, while the l-isomer is responsible for virtually all of the beta-blocking activity. Sotalol inhibits response to adrenergic stimuli by competitively blocking &#946;<sub>1</sub>-adrenergic receptors within the myocardium and &#946;<sub>2</sub>-adrenergic receptors within bronchial and vascular smooth muscle. The electrophysiologic effects of sotalol may be due to its selective inhibition of the rapidly activating component of the potassium channel involved in the repolarization of cardiac cells. The class II electrophysiologic effects are caused by an increase in sinus cycle length (slowed heart rate), decreased AV nodal conduction, and increased AV nodal refractoriness, while the class III electrophysiological effects include prolongation of the atrial and ventricular monophasic action potentials, and effective refractory period prolongation of atrial muscle, ventricular muscle, and atrio-ventricular accessory pathways (where present) in both the anterograde and retrograde directions.
Spermine, also known as gerontine or musculamine, belongs to the class of organic compounds known as dialkylamines. These are organic compounds containing a dialkylamine group, characterized by two alkyl groups bonded to the amino nitrogen. The resultin N-carbamoylputrescine is acted on by a hydrolase to split off urea group, leaving putrescine. The precursor for synthesis of spermine is the amino acid ornithine. The intermediate is spermidine. Spermine is a drug. Spermine exists in all living species, ranging from bacteria to humans. 5'-methylthioadenosine and spermine can be biosynthesized from S-adenosylmethioninamine and spermidine through its interaction with the enzyme spermine synthase. Another pathway in plants starts with decarboxylation of L-arginine to produce agmatine. In humans, spermine is involved in spermidine and spermine biosynthesis. Outside of the human body, spermine is found, on average, in the highest concentration in oats. Spermine has also been detected, but not quantified in several different foods, such as sapodilla, mexican groundcherries, cloves, sourdocks, and sunflowers. This could make spermine a potential biomarker for the consumption of these foods. This decarboxylation gives putrescine. The name spermin was first used by the German chemists Ladenburg and Abel in 1888, and the correct structure of spermine was not finally established until 1926, simultaneously in England (by Dudley, Rosenheim, and Starling) and Germany (by Wrede et al.). In one pathway L-glutamine is the precursor to L-ornithine, after which the synthesis of spermine from L-ornithine follows the same pathway as in animals. Spermine is a potentially toxic compound.
Stavudine is only found in individuals that have used or taken this drug. It is a dideoxynucleoside analog that inhibits reverse transcriptase and has in vitro activity against HIV. [PubChem]Stavudine inhibits the activity of HIV-1 reverse transcriptase (RT) both by competing with the natural substrate dGTP and by its incorporation into viral DNA.
Styrene, also known as vinylbenzene or phenylethylene, belongs to the class of organic compounds known as styrenes. These are organic compounds containing an ethenylbenzene moiety. The metabolites of styrene are excreted mainly in the urine. Styrene is possibly neutral. Styrene is a sweet, balsamic, and floral tasting compound. Styrene has been detected, but not quantified, in several different foods, such as coffee and coffee products, fruits, cocoa and cocoa products, alcoholic beverages, and chinese cinnamons. This could make styrene a potential biomarker for the consumption of these foods. A minor pathway of styrene metabolism involves the formation of phenylacetaldehyde from styrene 7,8-oxide or cytochrome P450 conversion of styrene to pheylethanol and subsequent metabolism to phenylacetic acid. Styrene is formally rated as a possible carcinogen (by IARC 2B) and is also a potentially toxic compound. Styrene oxide is predominantly metabolized by epoxide hydrolase to form styrene glycol; the styrene glycol is subsequently converted to mandelic acid, phenylglyoxylic acid, and hippuric acid. Styrene, with regard to humans, has been found to be associated with several diseases such as nonalcoholic fatty liver disease and ulcerative colitis; styrene has also been linked to the inborn metabolic disorder celiac disease. Styrene may be absorbed following ingestion, inhalation, or dermal exposure. Breathing high levels of styrene may cause nervous system effects such as changes in color vision, tiredness, feeling drunk, slowed reaction time, concentration problems, or balance problems. Chest burning, wheezing, and dyspnea may also occur. Styrene causes nervous system depression and may be carcinogenic.
Oftentimes, serotonin levels in the brain become extremely erratic before the onset of a migraine. In an attempt to stabilize this, sumatriptan is administered to help aid in leveling the serotonin levels in the brain. Sumatriptan is structurally similar to serotonin, and is a 5-HT (5-HT1D) agonist, which is one of the receptors that serotonin binds to. The specific receptor subtype it activates is present in the cranial and basilar arteries. Activation of these receptors causes vasoconstriction of those dilated arteries. Sumatriptan is also shown to decrease the activity of the trigeminal nerve. Sumatriptan is a triptan drug including a sulfonamide group structurally similar to serotonin, and is a 5-HT (5-HT1D) agonist, which is one of the receptors that serotonin binds to. Oftentimes, serotonin levels in the brain become extremely erratic before the onset of a migraine. In an attempt to stabilize this, sumatriptan is administered to help aid in leveling the serotonin levels in the brain. A serotonin agonist that acts selectively at 5HT1 receptors. It is used in the treatment of migraines. Sumatriptan (Imitrex, Imigran, Imigran Recovery) is a triptan drug including a sulfonamide group which was originally developed by Glaxo for the treatment of migraine headaches.
p-Synephrine is an endogenous amine in plasma, in variable levels with a tendency to be higher in hypertensive patients (PMID 8255371).
Tacrine is only found in individuals that have used or taken this drug. It is a centerally active cholinesterase inhibitor that has been used to counter the effects of muscle relaxants, as a respiratory stimulant, and in the treatment of Alzheimer's disease and other central nervous system disorders. [PubChem]The mechanism of tacrine is not fully known, but it is suggested that the drug is an anticholinesterase agent which reversibly binds with and inactivates cholinesterases. This inhibits the hydrolysis of acetylcholine released from functioning cholinergic neurons, thus leading to an accumulation of acetylcholine at cholinergic synapses. The result is a prolonged effect of acetylcholine.
Tacrolimus (also FK-506 or Fujimycin) is an immunosuppressive drug whose main use is after organ transplant to reduce the activity of the patient's immune system and so the risk of organ rejection. It is also used in a topical preparation in the treatment of severe atopic dermatitis, severe refractory uveitis after bone marrow transplants, and the skin condition vitiligo. It was discovered in 1984 from the fermentation broth of a Japanese soil sample that contained the bacteria Streptomyces tsukubaensis. Tacrolimus is chemically known as a macrolide. It reduces peptidyl-prolyl isomerase activity by binding to the immunophilin FKBP-12 (FK506 binding protein) creating a new complex. This FKBP12-FK506 complex interacts with and inhibits calcineurin thus inhibiting both T-lymphocyte signal transduction and IL-2 transcription.
Tadalafil is an orally adminstered drug used to treat male erectile dysfunction (impotence). It is marketed worldwide under the brand name Cialis. It is a phosphodiesterase 5 (PDE5) inhibitor. Tadalafil's distinguishing pharmacologic feature is its longer half-life (17.5 hours) compared with Viagra and Levitra (4-5 hours). This longer half-life results in a longer duration of action and is, in part, responsible for the Cialis nickname of the 'weekend pill.' This longer half-life also is the basis of current investigation for tadalafil's use in pulmonary arterial hypertension as a once-daily therapy. [Wikipedia]
L-Targinine is found in pulses. L-Targinine is isolated from broad bean seed L-Targinine has been identified in the human placenta (PMID: 32033212).
Taurocholic acid is a bile acid and is the product of the conjugation of cholic acid with taurine. Its sodium salt is the chief ingredient of the bile of carnivorous animals. Bile acids are steroid acids found predominantly in the bile of mammals. The distinction between different bile acids is minute, depending only on the presence or absence of hydroxyl groups on positions 3, 7, and 12. Bile acids are physiological detergents that facilitate excretion, absorption, and transport of fats and sterols in the intestine and liver. Bile acids are also steroidal amphipathic molecules derived from the catabolism of cholesterol. They modulate bile flow and lipid secretion, are essential for the absorption of dietary fats and vitamins, and have been implicated in the regulation of all the key enzymes involved in cholesterol homeostasis. Bile acids recirculate through the liver, bile ducts, small intestine, and portal vein to form an enterohepatic circuit. They exist as anions at physiological pH, and consequently require a carrier for transport across the membranes of the enterohepatic tissues. The unique detergent properties of bile acids are essential for the digestion and intestinal absorption of hydrophobic nutrients. Bile acids have potent toxic properties (e.g. membrane disruption) and there are a plethora of mechanisms to limit their accumulation in blood and tissues (PMID: 11316487, 16037564, 12576301, 11907135). Taurocholic acid, as with all bile acids, acts as a detergent to solubilize fats for absorption and is itself absorbed. It is used as a cholagogue and choleretic (a bile purging agent). Hydrolysis of taurocholic acid yields taurine, a nonessential amino acid. Taurocholic acid is one of the main components of urinary nonsulfated bile acids in biliary atresia. Raised levels of taurocholate in fetal serum in obstetric cholestasis may result in the development of a fetal dysrhythmia and sudden intra-uterine death (PMID: 3944741, 11256973).
Telmisartan is an angiotensin II receptor antagonist (ARB) used in the management of hypertension. Generally, angiotensin II receptor blockers (ARBs) such as telmisartan bind to the angiotensin II type 1 (AT1) receptors with high affinity, causing inhibition of the action of angiotensin II on vascular smooth muscle, ultimately leading to a reduction in arterial blood pressure. Recent studies suggest that telmisartan may also have PPAR-gamma agonistic properties that could potentially confer beneficial metabolic effects.
Temazepam is only found in individuals that have used or taken this drug. It is a benzodiazepine that acts as a gamma-aminobutyric acid modulator and anti-anxiety agent. [PubChem]Benzodiazepines bind nonspecifically to benzodiazepine receptors, which affects muscle relaxation, anticonvulsant activity, motor coordination, and memory. As benzodiazepine receptors are thought to be coupled to gamma-aminobutyric acid-A (GABA<sub>A</sub>) receptors, this enhances the effects of GABA by increasing GABA affinity for the GABA receptor. Binding of the inhibitory neurotransmitter GABA to the site opens the chloride channel, resulting in a hyperpolarized cell membrane that prevents further excitation of the cell.
Temozolomide (Temodar and Temodal) is an oral alkylating agent used for the treatment of refractory anaplastic astrocytoma -- a type of cancerous brain tumor. Temozolomide is not active until it is converted at physiologic pH to the active form, 5-(3-methyltriazen-1-yl)imidazole-4-carboxamide (MTIC).
Terazosin is a selective alpha1-antagonist used for treatment of symptoms of benign prostatic hyperplasia (BPH). It also acts to lower blood pressure, so it is a drug of choice for men with hypertension and prostate enlargement. It works by blocking the action of adrenaline on smooth muscle of the bladder and the blood vessel walls.
Terbinafine hydrochloride (Lamisil) is a synthetic allylamine antifungal. It is highly lipophilic in nature and tends to accumulate in skin, nails, and fatty tissues. Like other allylamines, terbinafine inhibits ergosterol synthesis by inhibiting the fungal squalene monooxygenase (squalene 2,3-epoxidase), an enzyme that is part of the fungal cell wall synthesis pathway.
L-Theanine, also known as L-gamma-glutamylethylamide or N-gamma-ethyl-L-glutamine, is a member of the class of compounds known as glutamine and derivatives. These compounds contain glutamine or a derivative thereof resulting from a reaction of glutamine at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom. L-Theanine is slightly soluble (in water) and a moderately acidic compound (based on its pKa). L-Theanine can be found in saliva. The regulatory status of theanine varies by country. In Japan, L-theanine has been approved for use in all foods, including herb teas, soft drinks, and desserts. Restrictions apply to infant foods. In the United States, the Food and Drug Administration (FDA) considers it to be generally recognized as safe (GRAS) and allows its sale as a dietary supplement. The German Federal Institute for Risk Assessment, an agency of their Federal Ministry of Food and Agriculture, objects to the addition of L-theanine to beverages. The European Food Safety Authority EFSA advised negatively on health claims related to L-theanine and cognitive function, alleviation of psychological stress, maintenance of normal sleep, and reduction of menstrual discomfort. Therefore, health claims for L-theanine are prohibited in the European Union (Wikipedia). L-Theanine is found in mushrooms and is a constituent of tea (Thea sinensis) and of the fungus Imleria badia. L-Theanine has been shown to exhibit neuroprotectant and neuroprotective functions (PMID: 20416364, 20416364).
D-Threitol can be regarded as the main end product of D-xylose metabolism in hummans. Threitol is a C4-polyol (tetritol); the total C4-polyol concentration of threitol decreases with age. Several inborn errors of metabolism with abnormal polyol concentrations in body fluids are known to date (such as pentosuria and galactosemia). Most of these defects can be diagnosed by the assessment of urinary concentrations of polyols. Several studies have revealed that urinary levels of some polyols may vary in diseases associated with carbohydrate metabolism derangements such as diabetes mellitus and uremia. The abnormal occurrence of various polyols in diseases with a specific enzyme deficiency such as pentosuria and galactosemia has also been reported (PMID:908147, 16435188, 14988808). Moreover, D-Threitol is found to be associated with ribose-5-phosphate isomerase deficiency, which is also an inborn error of metabolism. Threitol in the urine is a biomarker for the consumption of apples and other fruits.
Thymidine, also known as deoxythymidine or deoxyribosylthymine or thymine deoxyriboside, is a pyrimidine deoxynucleoside. It consists of the nucleobase thymine attached to deoxyribose through a beta N- glycosidic bond. Thymidine also belongs to the class of organic compounds known as pyrimidine 2'-deoxyribonucleosides. Pyrimidine 2'-deoxyribonucleosides are compounds consisting of a pyrimidine linked to a ribose which lacks a hydroxyl group at position 2. Deoxythymidine (or thymidine) is the DNA nucleoside T, which pairs with deoxyadenosine (A) in double-stranded DNA. Therefore, thymidine is essential to all life. Indeed, thymidine exists in all living species, ranging from bacteria to plants to humans. Within humans, thymidine participates in a number of enzymatic reactions. In particular, thymidine can be biosynthesized from 5-thymidylic acid through its interaction with the enzyme cytosolic purine 5'-nucleotidase. In addition, thymidine can be converted into 5-thymidylic acid; which is catalyzed by the enzyme thymidine kinase. Deoxythymidine can be phosphorylated with one, two or three phosphoric acid groups, creating dTMP (deoxythymidine monophosphate), dTDP, or dTTP (for the di- and tri- phosphates, respectively). dTMP can be incorporated into DNA via DNA polymerases. In cell biology, thymidine can be used to synchronize the cells in S phase. Derivatives of thymidine are used in a number of drugs, including Azidothymidine (AZT), which is used in the treatment of HIV infection. AZT inhibits the process of reverse transcription in the human immunodeficiency virus.
5-Thymidylic acid (conjugate base thymidylate), also known as thymidine monophosphate (TMP), deoxythymidine monophosphate (dTMP), or deoxythymidylic acid (conjugate base deoxythymidylate), is a nucleotide that is used as a monomer in DNA. It is an ester of phosphoric acid with the nucleoside thymidine. dTMP consists of a phosphate group, the pentose sugar deoxyribose, and the nucleobase thymine. Unlike the other deoxyribonucleotides, thymidine monophosphate often does not contain the "deoxy" prefix in its name; nevertheless, its symbol often includes a "d" ("dTMP"). 5-Thymidylic acid belongs to the class of organic compounds known as pyrimidine 2'-deoxyribonucleoside monophosphates. These are pyrimidine nucleotides with a monophosphate group linked to the ribose moiety lacking a hydroxyl group at position 2. The neutral species of 5-Thymidylic acid (2'-deoxythymidine 5'-monophosphate). 5-Thymidylic acid exists in all living species, ranging from bacteria to humans. Within humans, 5-thymidylic acid participates in a number of enzymatic reactions. In particular, 5-thymidylic acid and dihydrofolic acid can be biosynthesized from dUMP and 5,10-methylene-THF by the enzyme thymidylate synthase. In addition, 5-thymidylic acid can be converted into dTDP; which is catalyzed by the enzyme thymidylate synthase. In humans, 5-thymidylic acid is involved in pyrimidine metabolism. Outside of the human body, 5-Thymidylic acid has been detected, but not quantified in several different foods, such as common buckwheats, corn salad, garden cress, squashberries, and star fruits.
Thymol is a phenol obtained from thyme oil or other volatile oils. It is used as a stabilizer in pharmaceutic preparations. It has been used for its antiseptic, antibacterial, and antifungal actions, and was formerly used as a vermifuge. Thymol is a monoterpene phenol derivative of cymene, C10H13OH, isomeric with carvacrol, found in oil of thyme, and extracted as a white crystalline substance of a pleasant aromatic odor and strong antiseptic properties. It is also called "hydroxy cymene". In a 1994 report released by five top cigarette companies, thymol is one of the 599 additives to cigarettes. Its use or purpose, however, is unknown, like most cigarette additives.
Tiagabine is an anti-convulsive medication. It is also used in the treatment for panic disorder as are a few other anticonvulsants. Though the exact mechanism by which tiagabine exerts its effect on the human body is unknown, it does appear to operate as a selective GABA reuptake inhibitor.
Ticlopidine is an effective inhibitor of platelet aggregation. The drug has been found to significantly reduce infarction size in acute myocardial infarcts and is an effective antithrombotic agent in arteriovenous fistulas, aorto-coronary bypass grafts, ischemic heart disease, venous thrombosis, and arteriosclerosis. [PubChem]
Tinidazole is only found in individuals that have used or taken this drug. It is a nitroimidazole antitrichomonal agent effective against Trichomonas vaginalis, Entamoeba histolytica, and Giardia lamblia infections. [PubChem]Tinidazole is a prodrug and antiprotozoal agent. The nitro group of tinidazole is reduced in <i>Trichomonas</i> by a ferredoxin-mediated electron transport system. The free nitro radical generated as a result of this reduction is believed to be responsible for the antiprotozoal activity. It is suggested that the toxic free radicals covalently bind to DNA, causing DNA damage and leading to cell death. The mechanism by which tinidazole exhibits activity against <i>Giardia</i> and <i>Entamoeba</i> species is not known, though it is probably similar.
Tocainide is only found in individuals that have used or taken this drug. It is an antiarrhythmic agent which exerts a potential- and frequency-dependent block of sodium channels. [PubChem]Tocainide acts on sodium channels on the neuronal cell membrane, limiting the spread of seizure activity and reducing seizure propagation. Tocainide binds preferentially to the inactive state of the sodium channels.The antiarrhythmic actions are mediated through effects on sodium channels in Purkinje fibers.
Tolterodine is only found in individuals that have used or taken this drug. It is an antimuscarinic drug that is used to treat urinary incontinence. Tolterodine acts on M2 and M3 subtypes of muscarinic receptors.Both tolterodine and its active metabolite, 5-hydroxymethyltolterodine, act as competitive antagonists at muscarinic receptors. This antagonism results in inhibition of bladder contraction, decrease in detrusor pressure, and an incomplete emptying of the bladder.
Topotecan is only found in individuals that have used or taken this drug. It is an antineoplastic agent used to treat ovarian cancer. It works by inhibiting DNA topoisomerases, type I. [PubChem]Topotecan has the same mechanism of action as irinotecan and is believed to exert its cytotoxic effects during the S-phase of DNA synthesis. Topoisomerase I relieves torsional strain in DNA by inducing reversible single strand breaks. Topotecan binds to the topoisomerase I-DNA complex and prevents religation of these single strand breaks. This ternary complex interferes with the moving replication fork, which leads to the induction of replication arrest and lethal double-stranded breaks in DNA. As mammalian cells cannot efficiently repair these double strand breaks, the formation of this ternary complex eventually leads to apoptosis (programmed cell death).Topotecan mimics a DNA base pair and binds at the site of DNA cleavage by intercalating between the upstream (âˆ’1) and downstream (+1) base pairs. Intercalation displaces the downstream DNA, thus preventing religation of the cleaved strand. By specifically binding to the enzymeâ€“substrate complex, Topotecan acts as an uncompetitive inhibitor.
Ketorolac is only found in individuals that have used or taken this drug. It is a pyrrolizine carboxylic acid derivative structurally related to indomethacin. It is an NSAID and is used principally for its analgesic activity (from Martindale The Extra Pharmacopoeia, 31st ed). Ketorolac is a nonsteroidal anti-inflammatory drug (NSAID) chemically related to indomethacin and tolmetin. Ketorolac tromethamine is a racemic mixture of [-]S- and [+]R-enantiomeric forms, with the S-form having analgesic activity. Its antiinflammatory effects are believed to be due to inhibition of both cylooxygenase-1 (COX-1) and cylooxygenase-2 (COX-2) which leads to the inhibition of prostaglandin synthesis leading to decreased formation of precursors of prostaglandins and thromboxanes from arachidonic acid. The resultant reduction in prostaglandin synthesis and activity may be at least partially responsible for many of the adverse, as well as the therapeutic, effects of these medications. Analgesia is probably produced via a peripheral action in which blockade of pain impulse generation results from decreased prostaglandin activity. However, inhibition of the synthesis or actions of other substances that sensitize pain receptors to mechanical or chemical stimulation may also contribute to the analgesic effect. In terms of the ophthalmic applications of ketorolac - ocular administration of ketorolac reduces prostaglandin E2 levels in aqueous humor, secondary to inhibition of prostaglandin biosynthesis.
Torasemide (rINN) or torsemide (USAN) is a pyridine-sulfonylurea type loop diuretic mainly used in the management of edema associated with congestive heart failure. It is also used at low doses for the management of hypertension. It is marketed under the brand name Demadex. [Wikipedia]
Toremifene is only found in individuals that have used or taken this drug. It is a first generation nonsteroidal selective estrogen receptor modulator (SERM) that is structurally related to tamoxifen. Like tamoxifen, it is an estrogen agonist for bone tissue and cholesterol metabolism but is antagonistic on mammary and uterine tissue. [PubChem]Toremifene is a nonsteroidal triphenylethylene derivative. Toremifene binds to estrogen receptors and may exert estrogenic, antiestrogenic, or both activities, depending upon the duration of treatment, animal species, gender, target organ, or endpoint selected. The antitumor effect of toremifene in breast cancer is believed to be mainly due to its antiestrogenic effects, in other words, its ability to compete with estrogen for binding sites in the cancer, blocking the growth-stimulating effects of estrogen in the tumor. Toremifene may also inhibit tumor growth through other mechanisms, such as induction of apoptosis, regulation of oncogene expression, and growth factors.
Tramadol is only found in individuals that have used or taken this drug. It is a narcotic analgesic proposed for moderate to severe pain. It may be habituating (PubChem). Tramadol and its O-desmethyl metabolite (M1) are selective, weak OP3-receptor agonists. Opiate receptors are coupled with G-protein receptors and function as both positive and negative regulators of synaptic transmission via G-proteins that activate effector proteins. As the effector system is adenylate cyclase and cAMP is located at the inner surface of the plasma membrane, opioids decrease intracellular cAMP by inhibiting adenylate cyclase. Subsequently, the release of nociceptive neurotransmitters such as substance P, GABA, dopamine, acetylcholine, and noradrenaline is inhibited. The analgesic properties of tramadol can be attributed to norepinephrine and serotonin reuptake blockade in the CNS, which inhibits pain transmission in the spinal cord. The (+) enantiomer has a higher affinity for the OP3 receptor and preferentially inhibits serotonin uptake and enhances serotonin release. The (-) enantiomer preferentially inhibits norepinephrine reuptake by stimulating alpha(2)-adrenergic receptors.
A serotonin uptake inhibitor that is used as an antidepressive agent. It has been shown to be effective in patients with major depressive disorders and other subsets of depressive disorders. It is generally more useful in depressive disorders associated with insomnia and anxiety. This drug does not aggravate psychotic symptoms in patients with schizophrenia or schizoaffective disorders. (From AMA Drug Evaluations Annual, 1994, p309)
Triazolam is only found in individuals that have used or taken this drug.It is withdrawn in the United Kingdom due to risk of psychiatric adverse drug reactions. This drug continues to be available in the U.S. Internationally, triazolam is a Schedule IV drug under the Convention on Psychotropic Substances.Benzodiazepines bind nonspecifically to bezodiazepine receptors BNZ1, which mediates sleep, and BNZ2, which affects affects muscle relaxation, anticonvulsant activity, motor coordination, and memory. As benzodiazepine receptors are thought to be coupled to gamma-aminobutyric acid-A (GABA<sub>A</sub>) receptors, this enhances the effects of GABA by increasing GABA affinity for the GABA receptor. Binding of GABA to the site opens the chloride channel, resulting in a hyperpolarized cell membrane that prevents further excitation of the cell.
Trifluoperazine is only found in individuals that have used or taken this drug. It is a phenothiazine with actions similar to chlorpromazine. It is used as an antipsychotic and an antiemetic. [PubChem]Trifluoperazine blocks postsynaptic mesolimbic dopaminergic D1 and D2 receptors in the brain; depresses the release of hypothalamic and hypophyseal hormones and is believed to depress the reticular activating system thus affecting basal metabolism, body temperature, wakefulness, vasomotor tone, and emesis.
Oxcarbazepine is structurally a derivative of carbamazepine, adding an extra oxygen atom to the benzylcarboxamide group. This difference helps reduce the impact on the liver of metabolizing the drug, and also prevents the serious forms of anemia occasionally associated with carbamazepine. Aside from this reduction in side effects, it is thought to have the same mechanism as carbamazepine - sodium channel inhibition - and is generally used to treat partial seizures in epileptic children and adults.
Trimipramine is only found in individuals that have used or taken this drug. It is a tricyclic antidepressant similar to imipramine, but with more antihistaminic and sedative properties. [PubChem]Trimipramine's mechanism of action differs from other tricyclic antidepressants. Trimipramine acts by decreasing the reuptake of norepinephrine and serotonin (5-HT).
Trimipramine is only found in individuals that have used or taken this drug. It is a tricyclic antidepressant similar to imipramine, but with more antihistaminic and sedative properties. [PubChem]Trimipramine's mechanism of action differs from other tricyclic antidepressants. Trimipramine acts by decreasing the reuptake of norepinephrine and serotonin (5-HT).
Tripelennamine is only found in individuals that have used or taken this drug. It is a histamine H1 antagonist with low sedative action but frequent gastrointestinal irritation. It is used to treat asthma; HAY fever; urticaria; and rhinitis; and also in veterinary applications. Tripelennamine is administered by various routes, including topically. [PubChem]Tripelennamine binds to the histamine H1 receptor. This blocks the action of endogenous histamine, which subsequently leads to temporary relief of the negative symptoms brought on by histamine.
Tryptamine, also known as TrpN, is a catabolite of tryptophan converted by the gut microbiota. After absorption through the intestinal epithelium, tryptophan catabolites enter the bloodstream and are later excreted in the urine. Both Clostridium sp. and Ruminococcus sp. have been found to convert tryptophan into tryptamine (PMID: 30120222). Tryptamine is a monoamine compound that is a common precursor molecule to many hormones and neurotransmitters. Biosynthesis generally proceeds from the amino acid tryptophan, with tryptamine acting as a precursor for other compounds. Substitutions to the tryptamine molecule give rise to a group of compounds collectively known as tryptamines. The most well-known tryptamines are serotonin, an important neurotransmitter, and melatonin, a hormone involved in regulating the sleep-wake cycle. Tryptamine has been detected, but not quantified in, several different foods, such as onion-family vegetables, acerola, Japanese walnuts, custard apples, and green zucchinis. This could make tryptamine a potential biomarker for the consumption of these foods.
Tetrahydro-b-carbolines (THbCs)are potential neuroactive alkaloids found in chocolate and cocoa. The formation of 1,2,3,4-tetrahydro-/3-carbolines (THBCs), via the Pictet-Spengler condensation of tryptamines with formaldehyde, has been demonstrated repeatedly in incubations of various mammalian tissues containing added indolethylamine substrate and the methyl donors .5-methyltetrahydrofolate (5-MTHF) or S-adenosylmethionine(SAM). It is concluded that the formation of these THBCs is an artifact produced by the enzymatic liberation of formaldehyde from the methyl donors and the subsequent non-enzymatic condensation of this formaldehyde with the indole substrates. The formation of THBCs in vivo has thus remained a point of contention. (PMID: 7213417). 1,2,3,4-Tetrahydro-beta-carboline is a biomarker for the consumption of beer
Tyramine is a monoamine compound derived from the amino acid tyrosine. Tyramine is metabolized by the enzyme monoamine oxidase. In foods, it is often produced by the decarboxylation of tyrosine during fermentation or decay. Foods containing considerable amounts of tyramine include fish, chocolate, alcoholic beverages, cheese, soy sauce, sauerkraut, and processed meat. A large dietary intake of tyramine can cause an increase in systolic blood pressure of 30 mmHg or more. Tyramine acts as a neurotransmitter via a G protein-coupled receptor with high affinity for tyramine called TA1. The TA1 receptor is found in the brain as well as peripheral tissues including the kidney. An indirect sympathomimetic, Tyramine can also serve as a substrate for adrenergic uptake systems and monoamine oxidase so it prolongs the actions of adrenergic transmitters. It also provokes transmitter release from adrenergic terminals. Tyramine is a biomarker for the consumption of cheese
Urea is a highly soluble organic compound formed in the liver from ammonia produced by the deamination of amino acids. It is the principal end product of protein catabolism and constitutes about one half of the total urinary solids. Urea is formed in a cyclic pathway known simply as the urea cycle. In this cycle, amino groups donated by ammonia and L-aspartate are converted to urea. Urea is essentially a waste product; it has no physiological function. It is dissolved in blood (in humans in a concentration of 2.5 - 7.5 mmol/liter) and excreted by the kidney in the urine. In addition, a small amount of urea is excreted (along with sodium chloride and water) in human sweat. Urea is found to be associated with primary hypomagnesemia, which is an inborn error of metabolism.
N-carbamoylglutamic Acid, also known as N-Carbamoylglutamate, is classified as a glutamic acid or a Glutamic acid derivative. Glutamic acids are compounds containing glutamic acid or a derivative thereof resulting from reaction of glutamic acid at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom. N-carbamoylglutamic Acid is considered to be soluble (in water) and acidic
Uridine 5'-monophosphate (UMP), also known as uridylic acid or uridylate, belongs to the class of organic compounds known as pyrimidine ribonucleoside monophosphates. These are pyrimidine ribobucleotides with monophosphate group linked to the ribose moiety. UMP consists of a phosphate group, a pentose sugar ribose, and the nucleobase uracil; hence, it is a ribonucleotide monophosphate. Uridine 5'-monophosphate exists in all living species, ranging from bacteria to plants to humans. UMP is a nucleotide that is primarily used as a monomer in RNA biosynthesis. Uridine monophosphate is formed from Orotidine 5'-monophosphate (orotidylic acid) in a decarboxylation reaction catalyzed by the enzyme orotidylate decarboxylase. Within humans, uridine 5'-monophosphate participates in a number of enzymatic reactions. In particular, uridine 5'-monophosphate can be converted into uridine 5'-diphosphate through the action of the enzyme UMP-CMP kinase. In addition, uridine 5'-monophosphate can be biosynthesized from uridine 5'-diphosphate through its interaction with the enzyme soluble calcium-activated nucleotidase 1. In brain research studies, uridine monophosphate has been used as a convenient delivery compound for uridine.  Uridine is present in many foods, mainly in the form of RNA. Non-phosphorylated uridine is not bioavailable beyond first-pass metabolism. In a study, gerbils fed a combination of uridine monophosphate, choline, and docosahexaenoic acid (DHA) were found to have significantly improved performance in running mazes over those not fed the supplements, implying an increase in cognitive function (PMID: 18606862).
This compound belongs to the family of Pyrimidine Nucleotide Sugars. These are pyrimidine nucleotides bound to a saccharide derivative through the terminal phosphate group.
Urocanic acid (CAS: 104-98-3) is a breakdown (deamination) product of histidine. In the liver, urocanic acid is an intermediate in the conversion of histidine to glutamic acid, whereas, in the epidermis, it accumulates and may be both a UV protectant and an immunoregulator. Urocanic acid (UA) exists as a trans isomer (t-UA, approximately 30 mg/cm2) in the uppermost layer of the skin (stratum corneum). t-UA is formed as the cells of the second layer of the skin become metabolically inactive. During this process, proteins and membranes degrade, histidine is released, and histidase (histidine ammonia lyase) catalyzes the deamination of histidine to form t-UA. t-UA accumulates in the epidermis until removal by either the monthly skin renewal cycle or sweat. Upon absorption of UV light, the naturally occurring t-UA isomerizes to its cis form, c-UA. Because DNA lesions (e.g., pyrimidine dimers) in the lower epidermis can result from UV-B absorption, initial research proposed that t-UA acted as a natural sunscreen absorbing UV-B in the stratum corneum before the damaging rays could penetrate into lower epidermal zones. Researchers have found that c-UA also suppresses contact hypersensitivity and delayed hypersensitivity, reduces the Langerhans cell count in the epidermis, prolongs skin-graft survival time, and affects natural killer cell activity. (E)-Urocanic acid is found in mushrooms. It has been isolated from Coprinus atramentarius (common ink cap) and Phallus impudicus (common stinkhorn).
Valaciclovir (INN) or valacyclovir (USAN) is an antiviral drug used in the management of herpes simplex and herpes zoster (shingles). It is a prodrug, being converted in vivo to aciclovir. It is marketed by GlaxoSmithKline under the trade name Valtrex or Zelitrex. [Wikipedia]
Valdecoxib is a prescription drug used in the treatment of osteoarthritis, rheumatoid arthritis, and painful menstruation and menstrual symptoms. It is classified as a nonsteroidal anti-inflammatory drug, or NSAID, and should not be taken by anyone allergic to these types of medications.
Valsartan is an angiotensin-receptor blocker (ARB) that may be used to treat a variety of cardiac conditions including hypertension, diabetic nephropathy and heart failure. Valsartan lowers blood pressure by antagonizing the renin-angiotensin-aldosterone system (RAAS); it competes with angiotensin II for binding to the type-1 angiotensin II receptor (AT1) subtype and prevents the blood pressure increasing effects of angiotensin II. Unlike angiotensin-converting enzyme (ACE) inhibitors, ARBs do not have the adverse effect of dry cough. Valsartan may be used to treat hypertension, isolated systolic hypertension, left ventricular hypertrophy and diabetic nephropathy. It may also be used as an alternative agent for the treatment of heart failure, systolic dysfunction, myocardial infarction and coronary artery disease.
Vanillin, also known as vanillaldehyde or lioxin, belongs to the class of organic compounds known as methoxyphenols. Methoxyphenols are compounds containing a methoxy group attached to the benzene ring of a phenol moiety. It is used by the food industry as well as ethylvanillin. Vanillin exists in all living species, ranging from bacteria to humans. Vanillin is a sweet, chocolate, and creamy tasting compound. Vanillin is found, on average, in the highest concentration within a few different foods, such as corns, ryes, and sherries and in a lower concentration in beers, rums, and oats. Vanillin has also been detected, but not quantified, in several different foods, such as gooseberries, other bread, brazil nuts, shea tree, and ohelo berries. This could make vanillin a potential biomarker for the consumption of these foods. Vanillin is a potentially toxic compound. Synthetic vanillin, instead of natural Vanillin extract, is sometimes used as a flavouring agent in foods, beverages, and pharmaceuticals. Vanillin is the primary component of the extract of the Vanillin bean. Because of the scarcity and expense of natural Vanillin extract, there has long been interest in the synthetic preparation of its predominant component. Artificial Vanillin flavoring is a solution of pure vanillin, usually of synthetic origin. Today, artificial vanillin is made from either guaiacol or from lignin, a constituent of wood which is a byproduct of the paper industry. The first commercial synthesis of vanillin began with the more readily available natural compound eugenol.
Vardenafil (Levitra) is an oral therapy for the treatment of erectile dysfunction. It is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5). Penile erection is a hemodynamic process initiated by the relaxation of smooth muscle in the corpus cavernosum and its associated arterioles. During sexual stimulation, nitric oxide is released from nerve endings and endothelial cells in the corpus cavernosum. Nitric oxide activates the enzyme guanylate cyclase resulting in increased synthesis of cyclic guanosine monophosphate (cGMP) in the smooth muscle cells of the corpus cavernosum. The cGMP in turn triggers smooth muscle relaxation, allowing increased blood flow into the penis, resulting in erection. The tissue concentration of cGMP is regulated by both the rates of synthesis and degradation via phosphodiesterases (PDEs). The most abundant PDE in the human corpus cavernosum is the cGMPspecific phosphodiesterase type 5 (PDE5); therefore, the inhibition of PDE5 enhances erectile function by increasing the amount of cGMP.
Verapamil is only found in individuals that have used or taken this drug. Verapamil is a calcium channel blocker that is a class IV anti-arrhythmia agent. [PubChem]Verapamil inhibits voltage-dependent calcium channels. Specifically, its effect on L-type calcium channels in the heart causes a reduction in ionotropy and chronotropy, thuis reducing heart rate and blood pressure. Verapamil's mechanism of effect in cluster headache is thought to be linked to its calcium-channel blocker effect, but which channel subtypes are involved is presently not known. [PubChem] Calcium channel antagonists can be quite toxic. In the management of poisoning, early recognition is critical. Calcium channel antagonists are frequently prescribed, and the potential for serious morbidity and mortality with over dosage is significant. Ingestion of these agents should be suspected in any patient who presents in an overdose situation with unexplained hypotension and conduction abnormalities. The potential for toxicity should be noted in patients with underlying hepatic or renal dysfunction who are receiving therapeutic doses. (PMID 8213877).
Monoquaternary homolog of pancuronium. A non-depolarizing neuromuscular blocking agent with shorter duration of action than pancuronium. Its lack of significant cardiovascular effects and lack of dependence on good kidney function for elimination as well as its short duration of action and easy reversibility provide advantages over, or alternatives to, other established neuromuscular blocking agents. [PubChem]
Vincristine is only found in individuals that have used or taken this drug. It is an antitumor alkaloid isolated from Vinca Rosea. (Merck, 11th ed.)The antitumor activity of Vincristine is thought to be due primarily to inhibition of mitosis at metaphase through its interaction with tubulin. Like other vinca alkaloids, Vincristine may also interfere with: 1) amino acid, cyclic AMP, and glutathione metabolism, 2) calmodulin-dependent Ca<sup>2+</sup>-transport ATPase activity, 3) cellular respiration, and 4) nucleic acid and lipid biosynthesis.
Vindesine is only found in individuals that have used or taken this drug. It is a vinblastine derivative with antineoplastic activity against cancer. Major side effects are myelosuppression and neurotoxicity. Vindesine is used extensively in chemotherapy protocols (antineoplastic combined chemotherapy protocols). [PubChem]Vindesine acts by causing the arrest of cells in metaphase mitosis through its inhibition tubulin mitotic funcitoning. The drug is cell-cycle specific for the S phase.
Nevirapine is only found in individuals that have used or taken this drug. It is a potent, non-nucleoside reverse transcriptase inhibitor used in combination with nucleoside analogues for treatment of HIV infection and AIDS. [PubChem]Nevirapine binds directly to reverse transcriptase (RT) and blocks the RNA-dependent and DNA-dependent DNA polymerase activities by causing a disruption of the enzyme's catalytic site. The activity of nevirapine does not compete with template or nucleoside triphosphates.
Vitexin, also known as apigenin 8-C-glucoside or 8-glycosylapigenin, belongs to the class of organic compounds known as flavonoid 8-C-glycosides. Flavonoid 8-C-glycosides are compounds containing a carbohydrate moiety which is C-glycosidically linked to 8-position of a 2-phenylchromen-4-one flavonoid backbone. Vitexin is also described as an apigenin flavone glucoside. Vitexin has been found in passion flower, chasteberry, bamboo leaves, millet and Hawthorn. Vitexin has shown a wide range of pharmacological effects, such as antioxidant, anti-cancer, anti-inflammatory, anti-hyperalgesic, and neuroprotective effects (PMID: 27693342). Vitexin has also been shown to directly inhibit thyroid peroxidase and potentially contributes to goiter (PMID: 1696490). It is sometimes called a goitrogen.
Voriconazole (Vfend, Pfizer) is a triazole antifungal medication used to treat serious fungal infections. It is used to treat invasive fungal infections that are generally seen in patients who are immunocompromised. These include invasive candidiasis, invasive aspergillosis, and emerging fungal infections.
Warfarin is an anticoagulant that acts by inhibiting the synthesis of vitamin K-dependent coagulation factors. Warfarin is indicated for the prophylaxis and/or treatment of venous thrombosis and its extension, pulmonary embolism, and atrial fibrillation with embolization. It is also used as an adjunct in the prophylaxis of systemic embolism after myocardial infarction. Warfarin is also used as a rodenticide.
Xanthosine, also known as xanthine riboside, belongs to the class of organic compounds known as purine nucleosides. Purine nucleosides are compounds comprising a purine base attached to a ribosyl or deoxyribosyl moiety. Xanthosine is a nucleoside derived from xanthine and ribose. Xanthosine exists in all living species, ranging from bacteria to plants to humans. In plants xanthosine is the biosynthetic precursor to 7-methylxanthosine which is produced by the action of the enzyme known as 7-methylxanthosine synthase. 7-Methylxanthosine in turn is the precursor to theobromine (the active alkaloid in chocolate), which in turn is the precursor to caffeine, the active alkaloid in coffee and tea. Within humans, xanthosine participates in a number of enzymatic reactions. In particular, xanthosine can be biosynthesized from xanthylic acid; which is catalyzed by the enzyme cytosolic purine 5'-nucleotidase. In addition, xanthosine can be converted into xanthine and ribose 1-phosphate; which is mediated by the enzyme purine nucleoside phosphorylase. Xanthosine monophosphate (XMP) is an intermediate in purine metabolism, formed from IMP (inosine monophosphate).
Methoxsalen, also known as oxsoralen or 8-methoxypsoralen, belongs to the class of organic compounds known as 8-methoxypsoralens. These are psoralens containing a methoxy group attached at the C8 position of the psoralen group. Methoxsalen is a drug which is used for the treatment of psoriasis and vitiligo. Methoxsalen is a bitter tasting compound. Methoxsalen is found, on average, in the highest concentration within a few different foods, such as parsnips, parsley, and celery stalks and in a lower concentration in wild carrots, carrots, and fennels. Methoxsalen has also been detected, but not quantified, in several different foods, such as figs, green vegetables, corianders, dills, and fruits. Methoxsalen is a potentially toxic compound.
Zafirlukast is an oral leukotriene receptor antagonist (LTRA) for the maintenance treatment of asthma, often used in conjunction with an inhaled steroid and/or long-acting bronchodilator. It is available as a tablet and is usually dosed twice daily. Another leukotriene receptor antagonist is montelukast (Singulair), which is usually taken just once daily. Zafirlukast blocks the action of the cysteinyl leukotrienes on the CysLT1 receptors, thus reducing constriction of the airways, build-up of mucus in the lungs and inflammation of the breathing passages.
Zaleplon is a sedative/hypnotic, mainly used for insomnia. It is known as a nonbenzodiazepine hypnotic. Zaleplon interacts with the GABA receptor complex and shares some of the pharmacological properties of the benzodiazepines. Zaleplon is a schedule IV drug in the United States.
Leukotrienes are substances that induce numerous biological effects including augmentation of neutrophil and eosinophil migration, neutrophil and monocyte aggregation, leukocyte adhesion, increased capillary permeability, and smooth muscle contraction. These effects contribute to inflammation, edema, mucus secretion, and bronchoconstriction in the airways of asthmatic patients. Zileuton relieves such symptoms through its selective inhibition of 5-lipoxygenase, the enzyme that catalyzes the formation of leukotrienes from arachidonic acid. Specifically, it inhibits leukotriene LTB4, LTC4, LTD4, and LTE4 formation. Both the R(+) and S(-) enantiomers are pharmacologically active as 5-lipoxygenase inhibitors in in vitro systems.
Zolmitriptan is only found in individuals that have used or taken this drug. It is a synthetic tryptamine derivative and appears as a white powder that is readily soluble in water. [Wikipedia]Zolmitriptan binds with high affinity to human 5-HT<sub>1B</sub> and 5-HT<sub>1D</sub> receptors leading to cranial blood vessel constriction. Current theories proposed to explain the etiology of migraine headache suggest that symptoms are due to local cranial vasodilatation and/or to the release of sensory neuropeptides (vasoactive intestinal peptide, substance P and calcitonin gene-related peptide) through nerve endings in the trigeminal system. The therapeutic activity of zolmitriptan for the treatment of migraine headache can most likely be attributed to the agonist effects at the 5HT1B/1D receptors on intracranial blood vessels (including the arterio-venous anastomoses) and sensory nerves of the trigeminal system which result in cranial vessel constriction and inhibition of pro-inflammatory neuropeptide release.
Zolpidem (sold under the brand names Ambien, Ambien CR, Stilnox, and Sublinox) is a prescription medication used for the treatment of insomnia, as well as some brain disorders. It is a short-acting nonbenzodiazepine hypnotic of the imidazopyridine class that potentiates gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter, by binding to GABAA receptors at the same location as benzodiazepines. It works quickly (usually within 15 minutes) and has a short half-life (two to three hours). Zolpidem has not adequately demonstrated effectiveness in maintaining sleep (unless delivered in a controlled-release form); however, it is effective in initiating sleep. Some users take zolpidem recreationally for these side effects. However, it may be less common than benzodiazepine abuse. Zolpidem can become addictive if taken for extended periods of time, due to dependence on its ability to put one to sleep or to the euphoria it can sometimes produce.
xi-2,3-Dihydro-2-oxo-1H-indole-3-acetic acid is found in brassicas. xi-2,3-Dihydro-2-oxo-1H-indole-3-acetic acid is isolated from Ribes rubrum (currant), Brassica species and Helianthus annuus (sunflower). xi-2,3-Dihydro-2-oxo-1H-indole-3-acetic acid is a product of catabolism of 1H-Indole-3-acetic acid <ht>BNC14-M</ht> in Zea mays (sweetcorn
1,3,7-Trimethyluric acid is a methyl derivative of uric acid, found occasionally in human urine. 1,3,7-Trimethyluracil is one of the purine components in urinary calculi. Methylated purines originate from the metabolism of methylxanthines (caffeine, theophylline and theobromine). Methyluric acids are indistinguishable from uric acid by simple methods routinely used in clinical laboratories, requiring the use of high-performance liquid chromatography (HPLC). Purine derivatives in urinary calculi could be considered markers of abnormal purine metabolism. The content of a purine derivative in stone depends on its average urinary excretion in the general population, similarity to the chemical structure of uric acid, and content of the latter in stone. This suggests that purines in stones represent a solid solution with uric acid as solvent. It is also plausible that methylxanthines, ubiquitous components of the diet and drugs, are involved in the pathogenesis of urolithiasis. Caffeine is metabolized via successive pathways mainly catalyzed by CYP1A2, xanthine oxidase or N-acetyltransferase-2 to give 14 different metabolites. CYP1A2 activity shows an inter-individual variability among the population. CYP1A2, an isoform of the CYP1A cytochrome P450 super-family, is involved in the metabolism of many drugs and plays a potentially important role in the induction of chemical carcinogenesis. (PMID:11712316, 15833286, 3506820, 15013152).
1,7-Dimethyluric acid is the major urinary caffeine metabolite that is produced in the human body. 1,7-Dimethyluric acid is formed during caffeine metabolism and the process is catalyzed primarily by CYP2A6 (PMID: 18715882).
Paraxanthine, also known as p-xanthine, belongs to the class of organic compounds known as xanthines. These are purine derivatives with a ketone group conjugated at carbons 2 and 6 of the purine moiety. Paraxanthine exists in all living organisms, ranging from bacteria to humans. Within humans, paraxanthine participates in a number of enzymatic reactions. In particular, paraxanthine and formaldehyde can be biosynthesized from caffeine; which is catalyzed by the enzyme cytochrome P450 1A2. In addition, paraxanthine and acetyl-CoA can be converted into 5-acetylamino-6-formylamino-3-methyluracil through its interaction with the enzyme arylamine N-acetyltransferase 2. In humans, paraxanthine is involved in caffeine metabolism.
1-Aminocyclopropanecarboxylic acid is found in fruits. 1-Aminocyclopropanecarboxylic acid is isolated from apple and pear juice and cranberries.
1-Methyladenosine, also known as M1A, belongs to the class of organic compounds known as purine nucleosides. Purine nucleosides are compounds comprising a purine base attached to a ribosyl or deoxyribosyl moiety. Precise m6A mapping by m6A-CLIP/IP (briefly m6A-CLIP) revealed that a majority of m6A locates in the last exon of mRNAs in multiple tissues/cultured cells of mouse and human, and the m6A enrichment around stop codons is a coincidence that many stop codons locate round the start of last exons where m6A is truly enriched. The methylation of adenosine is directed by a large m6A methyltransferase complex containing METTL3 as the SAM-binding sub-unit. Insulin-like growth factor-2 mRNA-binding proteins 1, 2, and 3 (IGF2BP1-3) are reported as a novel class of m6A readers.
1-Methylguanosine is a methylated nucleoside. It is known that some modified, especially methylated, nucleosides originating from RNA degradation are excreted in abnormal levels in the urine of patients with malignant tumours. These nucleosides have been proposed as tumour markers. Their measurement could provide a non-invasive diagnostic method, help identify different cancers, and monitor any therapeutic effects (PMID:9129323).
Estriol-16-glucuronide is a glucuronide derivative of the steroid estriol where the glucuronic acid is attached to the 16-hydroxyl group of Estriol. Glucuronidation is used to assist in the excretion of toxic substances, drugs or other substances that cannot be used as an energy source. Glucuronic acid is attached via a glycosidic bond to the substance, and the resulting glucuronide, which has a much higher water solubility than the original substance, is eventually excreted by the kidneys. Estriol (also known as oestriol) is one of the three main estrogens produced by the human body. It is only produced in significant amounts during pregnancy as it is made by the placenta.
A dideoxynucleoside compound in which the 3&#39;-hydroxy group on the sugar moiety has been replaced by a hydrogen. This modification prevents the formation of phosphodiester linkages which are needed for the completion of nucleic acid chains. Didanosine is a potent inhibitor of HIV replication, acting as a chain-terminator of viral DNA by binding to reverse transcriptase; ddI is then metabolized to dideoxyadenosine triphosphate, its putative active metabolite. [PubChem]
Deoxyadenosine monophosphate (dAMP), also known as deoxyadenylic acid or deoxyadenylate in its conjugate acid and conjugate base forms, respectively, is a derivative of the common nucleic acid AMP, or adenosine monophosphate, in which the -OH (hydroxyl) group on the 2' carbon on the nucleotide's pentose has been reduced to just a hydrogen atom (hence the "deoxy-" part of the name). Additionally, the monophosphate of the name indicates that two of the phosphoryl groups of GTP have been removed, most likely by hydrolysis. It is a monomer used in DNA.
2'-Deoxyguanosine 5'-monophosphate, also known as deoxyguanylic acid or 2'-deoxy-GMP, belongs to the class of organic compounds known as purine 2'-deoxyribonucleoside monophosphates. These are purine nucleotides with monophosphate group linked to the ribose moiety lacking a hydroxyl group at position 2. 2'-Deoxyguanosine 5'-monophosphate is a purine 2'-deoxyribonucleoside 5'-monophosphate having guanine as the nucleobase. It exists in all living species, ranging from bacteria to humans. Within humans, 2'-deoxyguanosine 5'-monophosphate participates in a number of enzymatic reactions. In particular, 2'-deoxyguanosine 5'-monophosphate can be converted into dGDP which is mediated by the enzyme guanylate kinase. In addition, 2'-deoxyguanosine 5'-monophosphate can be converted into deoxyguanosine through its interaction with the enzyme cytosolic purine 5'-nucleotidase. In humans, 2'-deoxyguanosine 5'-monophosphate is involved in the metabolic disorder called the gout or kelley-seegmiller syndrome pathway.
2'-O-Methyluridine belongs to the class of organic compounds known as pyrimidine nucleosides. Pyrimidine nucleosides are compounds comprising a pyrimidine base attached to a ribosyl or deoxyribosyl moiety. 2'-O-Methyluridine was identified as one of forty plasma metabolites that could be used to predict gut microbiome Shannon diversity (PMID: 31477923). Shannon diversity is a metric that summarizes both species abundance and evenness, and it has been suggested as a marker for microbiome health.
2-Pyrocatechuic acid is a normal human benzoic acid metabolite found in plasma (PMID 16351159), and is normally found with increased levels after consumption of many nutrients and drugs, i.e.: cranberry juice (PMID 14733499), aspirin ingestion. (PMID 3342084) It has been found associated with idiopathic oro-facial pain due to stress (oxidative stress might enhance the production of free radicals); it has been suggested that OH radicals are responsible for the production of many systemic and local tissue injury diseases which may initially manifest as pain syndrome, and 2-Pyrocatechuic acid is a biological marker for the detection and quantification of OH radicals, and patients had significantly increased circulating levels of 2-Pyrocatechuic acid after aspirin ingestion than control subjects. (PMID 7748148).
2-Pyrocatechuic acid is a normal human benzoic acid metabolite found in plasma (PMID 16351159), and is normally found with increased levels after consumption of many nutrients and drugs, i.e.: cranberry juice (PMID 14733499), aspirin ingestion. (PMID 3342084) It has been found associated with idiopathic oro-facial pain due to stress (oxidative stress might enhance the production of free radicals); it has been suggested that OH radicals are responsible for the production of many systemic and local tissue injury diseases which may initially manifest as pain syndrome, and 2-Pyrocatechuic acid is a biological marker for the detection and quantification of OH radicals, and patients had significantly increased circulating levels of 2-Pyrocatechuic acid after aspirin ingestion than control subjects. (PMID 7748148).
2,4-Dibromophenol is found in crustaceans. Commonly found in molluscs and crustacean
Gentisate aldehyde is a substrate of the enzyme aldehyde oxidase 1 [EC:1.2.3.1] in Valine, leucine and isoleucine degradation, Tyrosine metabolism, Tryptophan metabolism, Vitamin B6 metabolism and Nicotinate and nicotinamide metabolism. (KEGG).
2,8-Quinolinediol, also known as quinoline-2,8-diol or 8-hydroxycarbostyril, belongs to the class of organic compounds known as quinolones and derivatives. Quinolones and derivatives are compounds containing a quinoline moiety that bears a ketone group. 2,8-Quinolinediol has been identified in urine (PMID: 30089834).
This compound belongs to the family of M-methoxybenzoic Acids and Derivatives. These are benzoic acids  in which the hydrogen atom at position 3 of the benzene ring is replaced by a methoxy group
Ciliatine is an organophosphorus compound isolated from human and animal tissues.
Deoxycytidine monophosphate (dCMP), also known as deoxycytidylic acid or deoxycytidylate in its conjugate acid and conjugate base forms, respectively, is a deoxynucleotide, and one of the four monomers that make up DNA. In a DNA double helix, it will base pair with deoxyguanosine monophosphate. dCMP belongs to the class of organic compounds known as pyrimidine 2'-deoxyribonucleoside monophosphates. These are pyrimidine nucleotides with a monophosphate group linked to the ribose moiety lacking a hydroxyl group at position 2. Deficiency of the enzyme deoxycytidine kinase (EC2.7.1.74) is associated with resistance to antiviral and anticancer chemotherapeutic agents, whereas increased enzyme activity is associated with increased activation of these compounds to cytotoxic nucleoside triphosphate derivatives. dCMP exists in all living species, ranging from bacteria to humans. Within humans, dCMP participates in a number of enzymatic reactions. In particular, dCMP can be converted to dCDP by the enzyme UMP-CMP kinase 2. In addition, dCMP can be converted into deoxycytidine, which is catalyzed by the enzyme cytosolic purine 5'-nucleotidase. In humans, dCMP is involved in the metabolic disorder called ump synthase deficiency (orotic aciduria). Outside of the human body, dCMP has been detected, but not quantified in several different foods, such as turnips, garlics, agaves, garden onions, and italian sweet red peppers. dCMP is a deoxycytosine nucleotide containing one phosphate group esterified to the deoxyribose moiety in the 2'-,3'- or 5- positions.
Deoxyuridine, also known as dU, belongs to the class of organic compounds known as pyrimidine 2'-deoxyribonucleosides. Pyrimidine 2'-deoxyribonucleosides are compounds consisting of a pyrimidine linked to a ribose which lacks a hydroxyl group at position 2. It is similar in chemical structure to uridine, but without the 2'-hydroxyl group. Deoxyuridine exists in all living organisms, ranging from bacteria to humans. Within humans, deoxyuridine participates in a number of enzymatic reactions. In particular, deoxyuridine can be biosynthesized from deoxycytidine through its interaction with the enzyme cytidine deaminase. In addition, deoxyuridine can be converted into uracil and deoxyribose 1-phosphate through its interaction with the enzyme thymidine phosphorylase. Deoxyuridine is considered to be an antimetabolite that is converted into deoxyuridine triphosphate during DNA synthesis. Laboratory suppression of deoxyuridine is used to diagnose megaloblastic anemia due to vitamin B12 and folate deficiencies. In humans, deoxyuridine is involved in the metabolic disorder called UMP synthase deficiency (orotic aciduria). Outside of the human body, deoxyuridine has been detected, but not quantified in, several different foods, such as lichee, highbush blueberries, agaves, macadamia nut (M. tetraphylla), and red bell peppers. This could make deoxyuridine a potential biomarker for the consumption of these foods.
Furoic acid is a metabolite that appears in the urine of workers occupationally exposed to furfural and is a marker of exposure to this compound. Furfural is a heterocyclic aldehyde that is commonly used as a solvent in industry. It is readily absorbed into the body via the lungs and has significant skin absorption. Furfural is an irritant of the eyes, mucous membranes, and skin and is a central nervous system depressant. Furfural as a confirmed animal carcinogen with unknown relevance to humans (It has been suggested that is a substance that produces hepatic cirrhosis). Once in the body, furfural is metabolized rapidly via oxidation to the metabolite furoic acid, which is then conjugated with glycine and excreted in the urine in both free and conjugated forms. (PMID: 3751566, 4630229, 12587683). 2-Furoic acid is a biomarker for the consumption of beer
2-Hydroxy-3-methylbutyric acid (also known as 2-hydroxyisovaleric acid) is a metabolite found in the urine of patients with phenylketonuria (PMID: 7978272), methylmalonic acidemia, propionic acidemia, 3-ketothiolase deficiency, isovaleric acidemia, 3-methylcrotonylglycemia, 3-hydroxy-3-methylglutaric acidemia, multiple carboxylase deficiency, glutaric aciduria, ornithine transcarbamylase deficiency, glyceroluria, tyrosinemia type I, galactosemia, and maple syrup urine disease (PMID: 11048741). 2-Hydroxyisovaleric acid has also been identified in the urine of patients with lactic acidosis and ketoacidosis (PMID: 884872), and in the urine of severely asphyxiated babies (PMID: 1610944). 2-Hydroxyisovaleric acid originates mainly from ketogenesis and from the metabolism of valine, leucine, and isoleucine (PMID: 6434570). 2-Hydroxy-3-methylbutyric acid has been identified in the human placenta (PMID: 32033212).
Leucinic acid, also known as leucic acid, 2-hydroxyisocaproic acid or 2-hydroxy-4-methylvaleric acid, belongs to the class of organic compounds known as hydroxy fatty acids. These are fatty acids in which the chain bears a hydroxyl group. Leucinic acid is a valeric acid derivative having a hydroxy substituent at the 2-position and a methyl substituent at the 4-position. It is an alpha-hydroxy analogue of leucine and a metabolite of the branched-chain amino acid leucine. Leucinic acid is found in all organisms ranging from bacteria to plants to animals. Leucinic acid has been found in a patient with dihydrolipoyl dehydrogenase (DLD) deficiency (PMID: 6688766). DLD deficiency is caused by mutations in the DLD gene and is inherited in an autosomal recessive manner. A common feature of dihydrolipoamide dehydrogenase deficiency is a potentially life-threatening buildup of lactic acid in tissues (lactic acidosis), which can cause nausea, vomiting, severe breathing problems, and an abnormal heartbeat. Neurological problems are also common in this condition; the first symptoms in affected infants are often decreased muscle tone (hypotonia) and extreme tiredness (lethargy). As the problems worsen, affected infants can have difficulty feeding, decreased alertness, and seizures. Liver problems can also occur in dihydrolipoamide dehydrogenase deficiency, ranging from an enlarged liver (hepatomegaly) to life-threatening liver failure. In some affected people, liver disease, which can begin anytime from infancy to adulthood, is the primary symptom. Leucinic acid is also present in the urine of patients with short bowel syndrome (PMID: 4018104)
2-Hydroxybenzaldehyde, also known as salicylal or O-formylphenol, belongs to the class of organic compounds known as hydroxybenzaldehydes. These are organic aromatic compounds containing a benzene ring carrying an aldehyde group and a hydroxyl group. 2-Hydroxybenzaldehyde is a cinnamon, cooling, and medical tasting compound. 2-Hydroxybenzaldehyde is found, on average, in the highest concentration within peppermints. 2-Hydroxybenzaldehyde has also been detected, but not quantified, in several different foods, such as common buckwheats, garden tomato (var.), herbs and spices, and tea. This could make 2-hydroxybenzaldehyde a potential biomarker for the consumption of these foods. 2-Hydroxybenzaldehyde is a potentially toxic compound.
2-coumaric acid, also known as o-coumaric acid, is a monohydroxycinnamic acid in which the hydroxy substituent is located at C-2 of the phenyl ring. It has a role as a plant metabolite. It is a conjugate acid of a 2-coumarate. It is a hydroxycinnamic acid, an organic compound that is a hydroxy derivative of cinnamic acid. There are three isomers of coumaric acids: o-coumaric acid, m-coumaric acid, and p-coumaric acid, that differ by the position of the hydroxy substitution of the phenyl group. 2-Hydroxycinnamic acid belongs to the class of organic compounds known as hydroxycinnamic acids. Hydroxycinnamic acids are compounds containing an cinnamic acid where the benzene ring is hydroxylated. 2-Hydroxycinnamic acid exists in all living organisms, ranging from bacteria to humans. 2-Hydroxycinnamic acid has been found in a few different foods, such as corns, hard wheats, and olives and in a lower concentration in pomegranates, american cranberries, and peanuts. 2-Hydroxycinnamic acid has also been detected, but not quantified in several different foods, such as carrots, soy beans, ryes, rye bread, and turmerics.
alpha-Hydroxyisobutyric acid is a metabolite of methyl tert-butyl ether (MTBE). MTBE may be obtained through environmental exposure. MTBE is rapidly eliminated from the body, mainly through expired air as the unchanged compound. MTBE is to some extent metabolized to t-butyl alcohol (TBA) and formaldehyde and oxidized to 2-methyl-1,2-propanediol and alpha-hydroxyisobutyric acid. alpha-Hydroxyisobutyric acid has been used as an aerial bactericide.
2-Hydroxynicotinic acid, also known as 2-hydroxypyridine-3-carboxylic acid, is a member of the class of compounds known as pyridinecarboxylic acids. Pyridinecarboxylic acids are compounds containing a pyridine ring bearing a carboxylic acid group. 2-Hydroxynicotinic acid is soluble (in water) and a weakly acidic compound (based on its pKa). 2-Hydroxynicotinic acid can be found in urine. 2-Hydroxynicotinic acid is a white to light yellow powder soluble in water. Its melting point is 258-261°C.
ortho-Hydroxyphenylacetic acid, also known as (o-hydroxyphenyl)acetate or 2-hydroxybenzeneacetic acid, is a member of the class of compounds known as 2(hydroxyphenyl)acetic acids. 2(Hydroxyphenyl)acetic acids are phenylacetic acids that carry a hydroxyl group at the 2-position. ortho-Hydroxyphenylacetic acid is slightly soluble (in water) and a weakly acidic compound (based on its pKa). ortho-Hydroxyphenylacetic acid can be found in a number of food items such as natal plum, lemon verbena, half-highbush blueberry, and parsley, which makes ortho-hydroxyphenylacetic acid a potential biomarker for the consumption of these food products. ortho-Hydroxyphenylacetic acid can be found primarily in blood, feces, and urine. Moreover, ortho-hydroxyphenylacetic acid is found to be associated with phenylketonuria, which is an inborn error of metabolism. ortho-Hydroxyphenylacetic acid is a substrate of the enzyme oxidoreductases (EC 1.14.13.-) in the pathway styrene degradation (KEGG). ortho-Hydroxyphenylacetic acid is also a microbial metabolite.
2-Methoxy-4-vinylphenol is an aromatic substance used as a flavoring agent. It is one of the compounds responsible for the natural aroma of buckwheat.
2-Methylglutaric acid, also known as alpha-methylglutarate or 2-methylpentanedioate, belongs to the class of organic compounds known as methyl-branched fatty acids. These are fatty acids with an acyl chain that has a methyl branch. Usually, they are saturated and contain only one or more methyl group. However, branches other than methyl may be present. 2-Methylglutaric acid is also classified as an alpha,omega-dicarboxylic acid. It is glutaric acid substituted at position 2 by a methyl group. 2-Methylglutaric acid arises from the microbial metabolism of the isoprenoid alkaloid pristane (PMID: 4327007; PMID: 20143352).
Propionylglycine is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acyl glycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13) which is an enzyme that catalyzes the chemical reaction:acyl-CoA + glycine < -- > CoA + N-acylglycineThe level of propionylglycine is elevated in patients with propionic acidemia, which is an inherited deficiency of propionyl-CoA carboxylase. (Disorders of propionate and methylmalonate metabolism. In The Metabolic and Molecular Bases of Inherited Disease).
3-Methylcytidine belongs to the class of organic compounds known as pyrimidine nucleosides. These are compounds comprising a pyrimidine base attached to a ribosyl or deoxyribosyl moiety. 3-Methylcytidine is a potential urinary biomarker of whole grain intake (PMID: 27805021). 3-Methylcytidine has been identified in the human placenta (PMID: 32033212).
3'-O-Methylguanosine is an endogenous methylated nucleoside found in human fluids. Methylated purine bases are present in higher amounts in tumor-bearing patients compared to healthy controls. DNA hypermethylation is a common finding in malignant cells and has been explored as a therapeutic target for hypomethylating agents. When chemical bonds to DNA, it becomes damaged and proper and complete replication cannot occur to make the normal intended cell. A DNA adduct is an abnormal piece of DNA covalently-bonded to a cancer-causing chemical. This has shown to be the start of a cancerous cell, or carcinogenesis. DNA adducts in scientific experiments are used as bio-markers and as such are themselves measured to reflect quantitatively, for comparison, the amount of cancer in the subject. (PMID: 3506820, 17044778, 17264127, 16799933).
Protocatechuic acid, also known as protocatechuate or 3,4-dihydroxybenzoate, belongs to the class of organic compounds known as hydroxybenzoic acid derivatives. Hydroxybenzoic acid derivatives are compounds containing a hydroxybenzoic acid (or a derivative), which is a benzene ring bearing a carboxyl and a hydroxyl groups. The enzyme protocatechuate 3,4-dioxygenase uses 3,4-dihydroxybenzoate and O2 to produce 3-carboxy-cis,cis-muconate. Protocatechuic acid is a drug. In the analogous hardening of the cockroach ootheca, the phenolic substance concerned is protocatechuic acid. Protocatechuic acid is a mild, balsamic, and phenolic tasting compound. Outside of the human body, protocatechuic acid is found, on average, in the highest concentration in a few different foods, such as garden onions, cocoa powders, and star anises and in a lower concentration in lentils, liquors, and red raspberries. Protocatechuic acid has also been detected, but not quantified in several different foods, such as cloud ear fungus, american pokeweeds, common mushrooms, fruits, and feijoa. This could make protocatechuic acid a potential biomarker for the consumption of these foods. It is also found in Allium cepa (17,540 ppm). It is a major metabolite of antioxidant polyphenols found in green tea. Similarly, PCA was reported to increase proliferation and inhibit apoptosis of neural stem cells. In vitro testing documented antioxidant and anti-inflammatory activity of PCA, while liver protection in vivo was measured by chemical markers and histological assessment.
3,4-Dihydroxymandelic acid, also known as DOMA or 3,4-dihydroxyphenylglycolate, belongs to the class of organic compounds known as catechols. Catechols are compounds containing a 1,2-benzenediol moiety. 3,4-Dihydroxymandelic acid exists in all living organisms, ranging from bacteria to humans. Within humans, 3,4-dihydroxymandelic acid participates in a number of enzymatic reactions. In particular, 3,4-dihydroxymandelic acid can be biosynthesized from 3,4-dihydroxymandelaldehyde through its interaction with the enzyme aldehyde dehydrogenase, dimeric nadp-preferring. In addition, 3,4-dihydroxymandelic acid and guaiacol can be converted into vanillylmandelic acid and pyrocatechol through the action of the enzyme catechol O-methyltransferase. In humans, 3,4-dihydroxymandelic acid is involved in the metabolic disorder called tyrosinemia type I. Outside of the human body, 3,4-Dihydroxymandelic acid has been detected, but not quantified in several different foods, such as yellow wax beans, soy beans, pomegranates, cucurbita (gourd), and daikon radish.
DL-DOPA, also known as (+-)-DOPA or (R,S)-DOPA or DL-3,4-dihydroxyphenylalanine is an alpha amino acid. These are amino acids in which the amino group is attached to the carbon atom immediately adjacent to the carboxylate group (alpha carbon). DL-DOPA also belongs to the class of organic compounds known as tyrosines and derivatives. Tyrosines and derivatives are compounds containing tyrosine or a derivative thereof resulting from reaction of tyrosine at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom. DL-DOPA is a racemic mixture of both D-DOPA and L-DOPA. D-DOPA is similar to L-DOPA (levodopa), but with opposite chirality. Levo- and dextro- rotation refer to a molecule's ability to rotate planes of polarized light in one or the other direction. Whereas L-DOPA is moderately effective in the treatment of Parkinson's disease (PD) by stimulating the production of dopamine in the brain, D-DOPA was at one time thought to be biologically inactive. However, it has recently been found that D-DOPA can be converted to L-DOPA and then to dopamine via the human enzyme known as D-amino acid oxidase and that racemic mixtures of DL-DOPA can be effective in treating Parkinsonism (PMID: 17924443; PMID: 3129126; PMID: 17042912).  The biological production or biosynthesis of D-DOPA is thought to occur through bacterial conversion of tyrosine.  L-DOPA is found naturally in both animals and plants. It is made via biosynthesis from the amino acid L-tyrosine by the enzyme tyrosine hydroxylase. L-DOPA is the precursor to the neurotransmitters dopamine, norepinephrine (noradrenaline), and epinephrine (adrenaline), which are collectively known as catecholamines.
3-(3-Hydroxyphenyl)propanoic (hMPP) acid is one of the major metabolites of ingested caffeic acid (PMID: 15479001) and of the phenolic degradation products of proanthocyanidins (the most abundant polyphenol present in chocolate) by the microflora in the colon (PMID: 12663291). mHPP is suspected to have antioxidants properties and is actively absorbed by the monocarboxylic acid transporter (MCT) in intestinal Caco-2 cell monolayers (PMID: 15479001, 12663291). hMPP has been found to be a metabolite of Clostridium, Escherichia, and Eubacterium (PMID: 28393285, 19520845). 3-(3-Hydroxyphenyl)propanoic acid is a flavonoid metabolite. 3-(3-Hydroxyphenyl)propanoic acid is a phenolic acid metabolite formed by the gut microflora detected after the consumption of whole grain.
3-Hydroxybenzyl alcohol (CAS Number 620-24-6) is a hydroxybenzyl alcohol that is phenol substituted at position C-3 by a hydroxymethyl group. It is a pink or beige to brown crystalline powder, soluble in water.
The use of tyrosine kinase receptor inhibitors is increasingly becoming a valuable therapeutic alternative in tumors carrying activated tyrosine kinase receptors. GMR beta tyrosine residues are not necessary for activation of the JAK/STAT pathway, or for proliferation, viability, or adhesion signaling in Ba/F3 cells, although tyrosine residues significantly affect the magnitude of the response. (PMID:10372132).
Beta-Guanidinopropionic acid is analog of creatine and is reported to decrease phosphocreatine and ATP content in animal tissues in vivo.
3-Hydroxyanthranilic acid, also known as 2-amino-3-hydroxy-benzoate or 3-ohaa, belongs to the class of organic compounds known as hydroxybenzoic acid derivatives. Hydroxybenzoic acid derivatives are compounds containing a hydroxybenzoic acid (or a derivative), which is a benzene ring bearing a carboxyl and a hydroxyl groups. 3-Hydroxyanthranilic acid is a drug. 3-Hydroxyanthranilic acid exists in all living species, ranging from bacteria to humans. Within humans, 3-hydroxyanthranilic acid participates in a number of enzymatic reactions. In particular, 3-hydroxyanthranilic acid and L-alanine can be biosynthesized from L-3-hydroxykynurenine through the action of the enzyme kynureninase. In addition, 3-hydroxyanthranilic acid can be converted into cinnavalininate through the action of the enzyme catalase. 3-Hydroxyanthranilic acid is an intermediate in the metabolism of tryptophan. In humans, 3-hydroxyanthranilic acid is involved in tryptophan metabolism. Outside of the human body, 3-hydroxyanthranilic acid has been detected, but not quantified in brassicas. This could make 3-hydroxyanthranilic acid a potential biomarker for the consumption of these foods. It is new antioxidant isolated from methanol extract of tempeh. It is effective in preventing autoxidation of soybean oil and powder, while antioxidant 6,7,4'-trihydroxyisoflavone is not.
3-Hydroxyglutaric acid is a member of the class of compounds known as dicarboxylic acids and derivatives. These are organic compounds containing exactly two carboxylic acid groups. 3-Hydroxyglutaric acid is soluble (in water) and a weakly acidic compound (based on its pKa). When present in sufficiently high levels, 3-hydroxyglutaric acid can act as an acidogen and a metabotoxin. An acidogen is an acidic compound that induces acidosis, which has multiple adverse effects on many organ systems. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Chronically high levels of 3-hydroxyglutaric acid are associated with glutaric aciduria type I (glutaric acidemia type I, glutaryl-CoA dehydrogenase deficiency, GA1, or GAT1). GA1 is an inherited disorder in which the body is unable to completely break down the amino acids lysine, hydroxylysine, and tryptophan due to a deficiency of mitochondrial glutaryl-CoA dehydrogenase (EC 1.3.99.7, GCDH). Excessive levels of their intermediate breakdown products (e.g. glutaric acid, glutaryl-CoA, 3-hydroxyglutaric acid, glutaconic acid) can accumulate and cause damage to the brain (and also other organs), but particularly the basal ganglia. GA1 is associated with a risk for intracranial and retinal hemorrhage, and non-specific white matter changes. Babies with glutaric acidemia type I are often born with unusually large heads (macrocephaly). Other symptoms include spasticity (increased muscle tone/stiffness) and dystonia (involuntary muscle contractions resulting in abnormal movement or posture), but many affected individuals are asymptomatic. Seizures and coma (encephalopathy) are rare. GA1 also causes secondary carnitine deficiency because 3-hydroxyglutaric acid, like other organic acids, is detoxified by carnitine.
Hydroxykynurenine is a free radical generator and a bioprecursor quinolinic acid which is a endogenous excitotoxin (PMID 16697652). It is a product of enzyme kynurenine 3-monooxygenase in the tryptophan catabolism pathway (Reactome http://www.reactome.org).
3-Hydroxyphenylacetic acid is a rutin metabolite and an antioxidant. It has a protective biological activity in human. It is a substrate of enzyme 4-hydroxyphenylacetate 3-monooxygenase [EC 1.14.13.3] in the pathway tyrosine metabolism (KEGG, PMID 155437). 3-Hydroxyphenylacetic acid is found to be associated with phenylketonuria, which is an inborn error of metabolism. It is also a marker of gut Clostridium species. Higher levels are associated with higher levels of Clostridia (PMID: 27123458). 3-Hydroxyphenylacetic acid can also be found in Klebsiella (PMID: 1851804).
3-Hydroxyvaleric acid may be products of the condensation of propionyl-CoA with acetyl-CoA catalyzed by 3-oxoacyl-CoA thiolases. An increase amount of 3-hydroxyvaleric acid can be found in methylmalonic acidemia and propionic acidemia. (PMID: 630060).
Indoleacetic acid (IAA) is a breakdown product of tryptophan metabolism and is often produced by the action of bacteria in the mammalian gut. Higher levels of IAA are associated with bacteria from Clostridium species including C. stricklandii, C. lituseburense, C. subterminale, and C. putrefaciens (PMID: 12173102). IAA can be found in Agrobacterium, Azospirillum, Bacillus, Bradyrhizobium, Clostridium, Enterobacter, Pantoea, Pseudomonas, Rhizobium (PMID: 12173102, PMID: 17555270, PMID: 12147474, PMID: 19400643, PMID: 9450337, PMID: 21397014) (https://link.springer.com/chapter/10.1007/978-1-4612-3084-7_7) (https://escholarship.org/uc/item/1bf1b5m3). Some endogenous production of IAA in mammalian tissues also occurs. It may be produced by the decarboxylation of tryptamine or the oxidative deamination of tryptophan. IAA frequently occurs at low levels in urine and has been found in elevated levels in the urine of patients with phenylketonuria (PMID: 13610897). IAA has also been identified as a uremic toxin according to the European Uremic Toxin Working Group (PMID: 22626821). Using material extracted from human urine, it was discovered by Kogl in 1933 that indoleacetic acid is also an important plant hormone (PMID: 13610897). Specifically, IAA is a member of the group of phytohormones called auxins. IAA is generally considered to be the most important native auxin. Plant cells synthesize IAA from tryptophan (Wikipedia). IAA and some derivatives can be oxidized by horseradish peroxidase (HRP) into cytotoxic species. IAA is only toxic after oxidative decarboxylation; the effect of IAA/HRP is thought to be due in part to the formation of methylene-oxindole, which may conjugate with DNA bases and protein thiols. IAA/HRP could be used as the basis for targeted cancer, a potential new role for plant auxins in cancer therapy (PMID: 11163327).
3-Indoleacetonitrile is a phytoalexin. Phytoalexins are antibiotics produced by plants that are under attack. Phytoalexins tend to fall into several classes including terpenoids, glycosteroids, and alkaloids; however, researchers often find it convenient to extend the definition to include all phytochemicals that are part of the plant's defensive arsenal. Phytoalexins produced in plants act as toxins to the attacking organism. They may puncture the cell wall, delay maturation, disrupt metabolism, or prevent the reproduction of the pathogen in question. However, phytoalexins are often targeted to specific predators; a plant that has anti-insect phytoalexins may not have the ability to repel a fungal attack. 3-Indoleacetonitrile is common in cruciferous vegetables such as cabbage, cauliflower, broccoli, and Brussels sprouts. Dietary indoles in cruciferous vegetables induce cytochrome P450 enzymes and have prevented tumours in various animal models. Consumption of Brassica vegetables is associated with a reduced risk of cancer of the alimentary tract in animal models and human populations (PMID:15612779, 15884814, 2342128, 3014947, 3880668, 6334634, 6419397, 6426808, 6584878, 6725517, 6838646, 7123561).
3-methylcatechol, also known as 2,3-dihydroxytoluene or 2,3-toluenediol, is a member of the class of compounds known as catechols. Catechols are compounds containing a 1,2-benzenediol moiety. 3-methylcatechol is soluble (in water) and a very weakly acidic compound (based on its pKa). 3-methylcatechol can be found in arabica coffee, beer, cocoa powder, and coffee, which makes 3-methylcatechol a potential biomarker for the consumption of these food products. 3-methylcatechol is a chemical compound .
3-Methylcrotonylglycine is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acyl glycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13) which is an enzyme that catalyzes the chemical reaction: acyl-CoA + glycine < -- > CoA + N-acylglycine. 3-Methylcrotonylglycine is a normal amino acid metabolite found in urine. Increased levels of this metabolite are found in patients suffering from leucine catabolic disorders, such as 3-methylcrotonyl-CoA carboxylase deficiency. 3-Methylcrotonylglycine is often considered to be a diagnostic marker of organic acidemias (PMID 11170888). Moreover, 3-methylcrotonylglycine is found to be associated with 3-hydroxy-3-methylglutaryl-CoA lyase deficiency and propionic acidemia, which are also inborn errors of metabolism.
Methylglutaric acid is a leucine metabolite. A large amount of methylglutaric acid is identified in urine of patients with deficiency of 3-methylglutaconyl coenzyme A hydratase (PMID 6181239). Methylglutaric acid is also found to be associated with 3-hydroxy-3-methylglutaryl-CoA lyase deficiency, another inborn error of metabolism.
3-Nitrotyrosine, also known as nitrotyrosine is a product of tyrosine nitration mediated by reactive nitrogen species such as peroxynitrite anion and nitrogen dioxide. Nitrotyrosine is identified as an indicator or marker of cell damage, inflammation as well as NO (nitric oxide) production. Nitrotyrosine is formed in the presence of the active metabolite NO. Nitrotyrosine belongs to the class of organic compounds known as tyrosine and derivatives. Tyrosine and derivatives are compounds containing tyrosine or a derivative thereof resulting from reaction of tyrosine at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom.
4-Acetamidobutanoic acid, also known as 4-acetamidobutanoate or N-acetyl-4-aminobutyric acid, is a member of the class of compounds known as gamma amino acids and derivatives. These compounds are amino acids having an -NH2 group attached to the gamma carbon atom. 4-Acetamidobutanoic acid is soluble in water. 4-Acetamidobutanoic acid can be found in a number of food items such as Rubus species (blackberry, raspberry), cassava, pepper (Capsicum frutescens), and napa cabbage, which makes 4-acetamidobutanoic acid a potential biomarker for the consumption of these food products. 4-Acetamidobutanoic acid can be found in blood, feces, and urine, as well as in human prostate tissue. 4-Acetamidobutanoic acid exists in all eukaryotes, ranging from yeast to humans. 4-Acetamidobutanoic acid is a GABA derivative, a product of the urea cycle and the metabolism of amino groups, and the product of NAD-linked aldehyde dehydrogenase (EC 1.2.1.3) (KEGG).
4-Acetylbutyrate belongs to the class of organic compounds known as medium-chain fatty acids. These are fatty acids with an aliphatic tail that contains between 4 and 12 carbon atoms.
4-aminophenol is considered a minor nephrotoxic metabolite of phenacetin and acetaminophen (paracetamol) in man. 4-Aminophenol can undergo autoxidations and metal-catalyzed and enzymatic oxidations in man to produce reactive oxygen species. (PMID 1713494).
4-Guanidinobutanoic acid, also known as gamma-guanidinobutyrate or 4-(carbamimidamido)butanoate, belongs to the class of organic compounds known as gamma amino acids and derivatives. These are amino acids having a (-NH2) group attached to the gamma carbon atom. 4-Guanidinobutanoic acid is a normal metabolite present in low concentrations. 4-Guanidinobutanoic acid exists in all eukaryotes, ranging from yeast to humans. Outside of the human body, 4-Guanidinobutanoic acid has been detected, but not quantified in a few different foods, such as apples, french plantains, and loquats. This could make 4-guanidinobutanoic acid a potential biomarker for the consumption of these foods. Patients with hyperargininemia have an arginase deficiency which leads to blockade of the urea cycle in the last step with several clinical symptoms. Owing to the arginase deficiency this patients accumulate arginine which leads eventually to epileptogenic guanidino compounds (PMID 7752905).
Diacetone alcohol is found in fruits. Diacetone alcohol is isolated from the arctic bramble Rubus arcticu
4-Hydroxybenzaldehyde, also known as 4-formylphenol or 4-hydroxybenzenecarbonal, belongs to the class of organic compounds known as hydroxybenzaldehydes. These are organic aromatic compounds containing a benzene ring carrying an aldehyde group and a hydroxyl group. A hydroxybenzaldehyde that is benzaldehyde substituted with a hydroxy group at position C-4. 4-Hydroxybenzaldehyde exists in all living organisms, ranging from bacteria to humans. 4-Hydroxybenzaldehyde is a sweet, almond, and balsam tasting compound. 4-Hydroxybenzaldehyde is found, on average, in the highest concentration within vinegars and oats. 4-Hydroxybenzaldehyde has also been detected, but not quantified, in several different foods, such as cardoons, colorado pinyons, oyster mushrooms, common chokecherries, and potato. This could make 4-hydroxybenzaldehyde a potential biomarker for the consumption of these foods.
4-Hydroxybenzeneacetonitrile is found in herbs and spices. 4-Hydroxybenzeneacetonitrile is isolated from white mustard (Brassica alba) as a decomposition product of 4-Hydroxybenzyl glucosinolate <ht>KZZ54-K</ht>
4-Hydroxyhippuric acid is a microbial end-product derived from polyphenol metabolism by the microflora in the intestine (PMID: 22932811). It is derived from 4-hydroxybenzoic acid derivatives which may undergo glycination in the liver and kidney (PMID: 20615997). 4-Hydroxyhippuric acid has been identified in the human placenta (PMID: 32033212).
p-Hydroxymandelic acid is an acidic metabolite of p-octopamine and p-synephrine (p-phenylephrine). It is also a naturally occurring metabolite of tyramine. A specific enantiomer of p-hydroxymandelic aicd ((R)-(-)-p-hydroxymandelic -- also called pisolithin B) has been shown to exhibit antifungal properties.
p-Hydroxyphenylacetic acid, also known as 4-hydroxybenzeneacetate, is classified as a member of the 1-hydroxy-2-unsubstituted benzenoids. 1-Hydroxy-2-unsubstituted benzenoids are phenols that are unsubstituted at the 2-position. p-Hydroxyphenylacetic acid is considered to be slightly soluble (in water) and acidic.  p-Hydroxyphenylacetic acid can be synthesized from acetic acid. It is also a parent compound for other transformation products, including but not limited to, methyl 2-(4-hydroxyphenyl)acetate, ixerochinolide, and lactucopicrin 15-oxalate.  p-Hydroxyphenylacetic acid can be found in numerous foods such as olives, cocoa beans, oats, and mushrooms. p-Hydroxyphenylacetic acid can be found throughout all human tissues and in all biofluids. Within a cell, p-hydroxyphenylacetic acid is primarily located in the cytoplasm and in the extracellular space. p-Hydroxyphenylacetic acid is also a microbial metabolite produced by Acinetobacter, Clostridium, Klebsiella, Pseudomonas, and Proteus. Higher levels of this metabolite are associated with an overgrowth of small intestinal bacteria from Clostridia species including C. difficile, C. stricklandii, C. lituseburense, C. subterminale, C. putrefaciens, and C. propionicum (PMID: 476929, 12173102). p-Hydroxyphenylacetic acid is detected after the consumption of whole grain.
Hydroxyphenyllactic acid or 4-hydroxyphenyllactate (the L-form) is a tyrosine metabolite. The level of L-hydroxyphenyllactic acid is elevated in patients with a deficiency of the enzyme p-hydroxyphenylpyruvate oxidase (EC 1.14.2.2) (PMID: 4720815). L-hydroxyphenyllactate is present in relatively higher concentrations in the cerebrospinal fluid and urine of patients with phenylketonuria (PKU) and tyrosinemia (PMID: 3126358). However, the D-form of hydroxyphenyllactate is of bacterial origin and is also found in individuals with bacterial overgrowth or unusual gut microflora (PMID: 3126358).  Microbial hydroxyphenyllactate is likely derived from phenolic or polyphenolic compounds in the diet.  Bifidobacteria and lactobacilli produce considerable amounts of phenyllactic and p-hydroxyphenyllactic acids (PMID: 23061754).  It has also been shown that hydroxyphenyllactate decreases ROS (reactive oxygen species) production in both mitochondria and neutrophils and so hydroxyphenyllactate may function as a natural anti-oxidant (PMID: 23061754). Hydroxyphenyllactic acid is a microbial metabolite found in Acinetobacter, Bacteroides, Bifidobacteria, Bifidobacterium, Clostridium, Enterococcus, Escherichia, Eubacterium, Klebsiella, Lactobacillus, Pseudomonas and Staphylococcus (PMID: 19961416).
4-Hydroxyphenylpyruvic acid (4-HPPA) is a keto acid that is involved in the tyrosine catabolism pathway. It is a product of the enzyme (R)-4-hydroxyphenyllactate dehydrogenase (EC 1.1.1.222) and is formed during tyrosine metabolism. The conversion from tyrosine to 4-HPPA is catalyzed by tyrosine aminotransferase. Additionally, 4-HPPA can be converted to homogentisic acid which is one of the precursors to ochronotic pigment. The enzyme 4-hydroxyphenylpyruvic acid dioxygenase (HPD) catalyzes the reaction that converts 4-hydroxyphenylpyruvic acid to homogentisic acid. A deficiency in the catalytic activity of HPD is known to lead to tyrosinemia type III, an autosomal recessive disorder characterized by elevated levels of blood tyrosine and massive excretion of tyrosine derivatives into urine. It has been shown that hawkinsinuria, an autosomal dominant disorder characterized by the excretion of 'hawkinsin,' may also be a result of HPD deficiency (PMID: 11073718). Moreover, 4-hydroxyphenylpyruvic acid is also found to be associated in phenylketonuria, which is also an inborn error of metabolism. There are two isomers of HPPA, specifically 4HPPA and 3HPPA, of which 4HPPA is the most common. 4-HPPA has been found to be a microbial metabolite in Escherichia (ECMDB).
4-Isopropylbenzoic acid is found in cumin. 4-Isopropylbenzoic acid is a constituent of various plant species including Cuminum cyminum (cumin), Ferula species and Perilla frutescens (perilla).
Ketoleucine is an abnormal metabolite that arises from the incomplete breakdown of branched-chain amino acids. Ketoleucine is both a neurotoxin and a metabotoxin. A neurotoxin causes damage to nerve cells and nerve tissues. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Chronically high levels of ketoleucine are associated with maple syrup urine disease (MSUD). MSUD is a metabolic disorder caused by a deficiency of the branched-chain alpha-keto acid dehydrogenase complex (BCKDC), leading to a buildup of the branched-chain amino acids (leucine, isoleucine, and valine) and their toxic by-products (ketoacids) in the blood and urine. The symptoms of MSUD often show in infancy and lead to severe brain damage if untreated. MSUD may also present later depending on the severity of the disease. If left untreated in older individuals, during times of metabolic crisis, symptoms of the condition include uncharacteristically inappropriate, extreme, or erratic behaviour and moods, hallucinations, anorexia, weight loss, anemia, diarrhea, vomiting, dehydration, lethargy, oscillating hypertonia and hypotonia, ataxia, seizures, hypoglycemia, ketoacidosis, opisthotonus, pancreatitis, rapid neurological decline, and coma.  In maple syrup urine disease, the brain concentration of branched-chain ketoacids can increase 10- to 20-fold. This leads to a depletion of glutamate and a consequent reduction in the concentration of brain glutamine, aspartate, alanine, and other amino acids. The result is a compromise of energy metabolism because of a failure of the malate-aspartate shuttle and a diminished rate of protein synthesis (PMID: 15930465).
4-Methylcatechol, also known as homocatechol or toluene-3,4-diol, belongs to the class of organic compounds known as catechols. Catechols are compounds containing a 1,2-benzenediol moiety. Outside of the human body, 4-Methylcatechol is found, on average, in the highest concentration within a few different foods such as coffee and cocoa powders and in a lower concentration in beers. 4-Methylcatechol has also been detected, but not quantified in eggplants. This could make 4-methylcatechol a potential biomarker for the consumption of these foods. Recent studies have suggested that a lack of brain-derived neurotrophic factor (BDNF) in the limbic system may cause neuropathic pain (PMID:22198556). It is both a substrate and a suicide inhibitor of catechol 2,3-dioxygenase (PMID:15006807). 4-Methylcatechol is a metabolite of homoprotocatechuic acid (PMID:4974346). 4-Methylcatechol is known to induce the production of BDNF.
4-methylumbelliferone is a substrate for: Liver carboxylesterase 1, Cocaine esterase, and S-formylglutathione hydrolase.
4-Nitrocatechol is the by-product of the hydroxylation of 4-nitrophenol by the human cytochrome P450 (CYP) 2E1. This reaction is a useful metabolic marker for the presence of functional cytochrome P450 2E1 in mammalian cell microsomes. Hepatic and extrahepatic microsomal cytochrome P450 isozymes further catalyze the reduction of p-nitrocatechol into p-aminophenol (PMID: 8267647, 8214571, 8267647).
4-Pyridoxic acid is a member of the class of compounds known as methylpyridines. More specifically it is a 2-methylpyridine derivative substituted by a hydroxy group at C-3, a carboxy group at C-4, and a hydroxymethyl group at C-5. 4-Pyridoxic acid is the catabolic product of vitamin B6 (also known as pyridoxine, pyridoxal and pyradoxamine) and is excreted in the urine. Urinary levels of 4-pyridoxic acid are lower in females than in males and will be reduced even further in persons with a riboflavin deficiency. 4-Pyridoxic acid is formed by the action of aldehyde oxidase I (an endogenous enzyme) and by microbial enzymes (pyridoxal 4-dehydrogenase), an NAD-dependent aldehyde dehydrogenase. 4-pyridoxic acid can be further broken down by the gut microflora via the enzyme known as 4-pyridoxic acid dehydrogenase. This enzyme catalyzes the four-electron oxidation of 4-pyridoxic acid to 3-hydroxy-2-methylpyridine-4,5-dicarboxylate, using nicotinamide adenine dinucleotide (NAD) as a cofactor.
4-hydroxystyrene occurs frequently in different ciders, wines, foods and berries, e.g. cloudberry. Styrene is a prohapten metabolized in the skin by aryl hydrocarbon hydroxylase (AHH, EC 1.14.14.1) to styrene epoxide acting as the true hapten. Styrene occurs in nature and as a synthetic product.(PMID: 6713846).
5'-Methylthioadenosine, also known as MTA or thiomethyladenosine, belongs to the class of organic compounds known as 5'-deoxy-5'-thionucleosides. These are 5'-deoxyribonucleosides in which the ribose is thio-substituted at the 5'position by a S-alkyl group. 5'-Methylthioadenosine is metabolized solely by MTA-phosphorylase, to yield 5-methylthioribose-1-phosphate and adenine, a crucial step in the methionine and purine salvage pathways, respectively. 5'-Methylthioadenosine exists in all living species, ranging from bacteria to humans. 5'-Methylthioadenosine (MTA) is a naturally occurring sulfur-containing nucleoside present in all mammalian tissues. Within humans, 5'-methylthioadenosine participates in a number of enzymatic reactions. In particular, 5'-methylthioadenosine and spermidine can be biosynthesized from S-adenosylmethioninamine and putrescine through the action of the enzyme spermidine synthase. In addition, 5'-methylthioadenosine can be converted into 5-methylthioribose 1-phosphate and L-methionine; which is catalyzed by the enzyme S-methyl-5'-thioadenosine phosphorylase. It is produced from S-adenosylmethionine mainly through the polyamine biosynthetic pathway, where it behaves as a powerful inhibitory product. For instance, 5'-Methylthioadenosine has been shown to influence the regulation of gene expression, proliferation, differentiation, and apoptosis (PMID:15313459). In humans, 5'-methylthioadenosine is involved in the metabolic disorder called hypermethioninemia. Outside of the human body, 5'-Methylthioadenosine has been detected, but not quantified in several different foods, such as soursops, allspices, summer grapes, alaska wild rhubarbs, and breadfruits. Elevated excretion appears in children with severe combined immunodeficiency syndrome (SCID) (PMID:3987052). Evidence suggests that 5'-Methylthioadenosine can affect cellular processes in many ways. 5'-Methylthioadenosine can be found in human urine.
Dimethylbenzimidazole is an intermediate in Riboflavin metabolism. Dimethylbenzimidazole is the second to last step for the synthesis of alpha-Ribazole. It is converted from Riboflavin then it is converted to N1-(5-Phospho-alpha-D-ribosyl)-5,6-dimethylbenzimidazole via the enzyme nicotinate-nucleotide--dimethylbenzimidazole phosphoribosyltransferase (EC 2.4.2.21).
5-Aminoimidazole-4-carboxamide is an imidazole derivative which is a metabolite of the antineoplastic agents BIC and DIC. By itself, or as the ribonucleotide, it is used as a condensation agent in the preparation of nucleosides and nucleotides. Compounded with orotic acid, it is used to treat liver diseases. -- Pubchem.
Mesalazine is only found in individuals that have used or taken this drug. It is an anti-inflammatory agent, structurally related to the salicylates, which is active in inflammatory bowel disease. It is considered to be the active moiety of sulphasalazine. (From Martindale, The Extra Pharmacopoeia, 30th ed)Although the mechanism of action of mesalazine is not fully understood, it appears to be topical rather than systemic. Mucosal production of arachidonic acid metabolites, both through the cyclooxygenase pathways, i.e., prostanoids, and through the lipoxygenase pathways, i.e., leukotrienes and hydroxyeicosatetraenoic acids, is increased in patients with chronic inflammatory bowel disease, and it is possible that mesalazine diminishes inflammation by blocking cyclooxygenase and inhibiting prostaglandin production in the colon.
Flucytosine is only found in individuals that have used or taken this drug. It is a fluorinated cytosine analog that is used as an antifungal agent. [PubChem]Although the exact mode of action is unknown, it has been proposed that flucytosine acts directly on fungal organisms by competitive inhibition of purine and pyrimidine uptake and indirectly by intracellular metabolism to 5-fluorouracil. Flucytosine enters the fungal cell via cytosine permease; thus, flucytosine is metabolized to 5-fluorouracil within fungal organisms. The 5-fluorouracil is extensively incorporated into fungal RNA and inhibits synthesis of both DNA and RNA. The result is unbalanced growth and death of the fungal organism. It also appears to be an inhibitor of fungal thymidylate synthase.
5-Hydroxyindoleacetic acid, also known as 5-hydroxyindole-3-acetate or 5-HIAA, belongs to the class of organic compounds known as indole-3-acetic acid derivatives. Indole-3-acetic acid derivatives are compounds containing an acetic acid (or a derivative) linked to the C3 carbon atom of an indole. 5-Hydroxyindoleacetic acid exists in all living organisms, ranging from bacteria to humans. In humans, 5-hydroxyindoleacetic acid is a breakdown product of serotonin that is excreted in the urine and it also participates in a number of enzymatic reactions. 5-hydroxyindoleacetic acid can be biosynthesized from 5-hydroxyindoleacetaldehyde; which is catalyzed by the mitochondrial enzyme aldehyde dehydrogenase. In addition, 5-hydroxyindoleacetic acid and S-adenosylmethionine can be converted into 5-methoxyindoleacetate and S-adenosylhomocysteine through its interaction with the enzyme acetylserotonin O-methyltransferase. 5-Hydroxyindoleacetic acid is also involved in the metabolism of tryptophan. 5-Hydroxyindoleacetic acid has been found to be associated with several human diseases such as brunner syndrome, friedreich's ataxia, schizophrenia, and olivopontocerebral atrophy; 5-hydroxyindoleacetic acid has also been linked to the inborn metabolic disorder sepiapterin reductase deficiency. Elevated levels of 5-hydroxyindoleacetic acid in urine (>20 uM) are indicative of appendicitis and gastroenteritis (PMID: 11462886). Serotonin and 5-Hydroxyindoleacetic acid are produced in excess amounts by carcinoid tumors, and levels of these substances may be measured in the urine to test for carcinoid tumors (NCI). 5-Hydroxyindoleacetic acid has also been found to be a product of human gut microbiota.
5-Methoxyindoleacetate, also known as 5-methoxy-IAA or 5-MIAA, belongs to the class of organic compounds known as indole-3-acetic acid derivatives. Indole-3-acetic acid derivatives are compounds containing an acetic acid (or a derivative) linked to the C3 carbon atom of an indole. 5-Methoxyindoleacetic acid is formed through oxidative deamination. It is identified in the urine, and the concentration is determined to be 1.3 µg/mL using GC-MS (PMID: 12908946). An increase in urinary 5-MIAA excretion was shown in patients with cancer of the stomach, rectum, and lung (PMID: 2446428).
5-Methylcytidine belongs to the class of organic compounds known as pyrimidine nucleosides. Pyrimidine nucleosides are compounds comprising a pyrimidine base attached to a ribosyl or deoxyribosyl moiety.
Ribothymidine is an endogenous methylated nucleoside found in human fluids; methylated purine bases are present in higher amounts in tumor-bearing patients compared to healthy controls.DNA hypermethylation is a common finding in malignant cells and has been explored as a therapeutic target for hypomethylating agents. When chemical bonds to DNA, the DNA becomes damaged and proper and complete replication cannot occur to make the normal intended cell. A DNA adduct is an abnormal piece of DNA covalently-bonded to a cancer-causing chemical. This has shown to be the start of a cancerous cell, or carcinogenesis. DNA adducts in scientific experiments are used as bio-markers and as such are themselves measured to reflect quantitatively, for comparison, the amount of cancer in the subject. (PMID:3506820, 17044778, 17264127, 16799933).
Aesculetin, also known as cichorigenin or cichoriin aglucon, belongs to the class of organic compounds known as 6,7-dihydroxycoumarins. These are coumarins bearing two hydroxyl groups at positions 6 and 7 of the coumarin skeleton, respectively. Aesculetin is found, on average, in the highest concentration within sherries. Aesculetin has also been detected, but not quantified, in several different foods, such as horseradish, carrots, dandelions, grape wines, and highbush blueberries. This could make aesculetin a potential biomarker for the consumption of these foods.
6-Hydroxyhexanoate was identified as the immediate product of hexanoate w-hydroxylation by whole cells and was further oxidized into adipic acid and an unexpected metabolite identified as 2-tetrahydrofuranacetic acid. This same metabolite, together with adipic acid, was also detected when similarly induced cells were incubated with hexanoate or 1,6-hexanediol, but not with 6-oxohexanoate (adipic semialdehyde).Cells grown on hexanoate and incubated with 6-hydroxyhexanoate were also found to accumulate 2-tetrahydrofuranacetic acid, which was not further degraded. Utilization of 6-hydroxyhexanoate for growth was restricted to those organisms also able to utilize adipate. Similar observations were made with 1,6-hexanediol serving as the carbon source and cells obtained from one organism,Pseudomonas aeruginosa PAO, grown either on 1,6-hexanediol or 6-hydroxyhexanoate,were found to be well induced for both 6-oxohexanoate and adipate oxidation. The results indicate that 6-hydroxyhexanoate and 1,6-hexanediol are susceptible to both 1B- and w-oxidative attack; however, the former pathway appears to be of no physiological significance since it generates 2-tetrahydrofuranacetic acid as a nonmetabolizable intermediate, making w-oxidation via adipate the exclusive pathway for degradation.
6-Hydroxynicotinic acid (6-OHNA) is exploited in the use of NMR spectroscopy or gas chromatography--mass spectrometry for the diagnosis of Pseudomonas aeruginosa in urinary tract infection. Among the common bacteria causing urinary infection, only P. aeruginosa produces 6-hydroxynicotinic acid from nicotinic acid. Pseudomonas aeruginosa infection has been reported to be the third leading cause of urinary infection, accounting for 11% of such infections, the first and second being Escherichia coli and Klebsiella pneumonia, respectively. Analyses of the NMR spectra of the bacterial media with variable cell count of P. aeruginosa, shows that the intensity of the signals of the 6-hydroxynicotinic acid increases with increasing number of bacterial cells (PMID:3926801, 15759292). 6-hydroxynicotinic acid can also be found in Achromobacter and Serratia.
6-Methylmercaptopurine is a metabolite of mercaptopurine. Mercaptopurine (also called 6-mercaptopurine, 6-MP or its brand name Purinethol) is an immunosuppressive drug. It is a thiopurine. (Wikipedia)
This compound belongs to the family of Phenanthrenes and Derivatives. These are polycyclic compounds containing a phenanthrene moiety, which is a tricyclic aromatic compound with three non-linearly fused benzene.
Acetaminophen glucuronide is a natural human metabolite of Acetaminophen generated in the liver by UDP glucuonyltransferase. Glucuronidation is used to assist in the excretion of toxic substances, drugs or other substances that cannot be used as an energy source. Glucuronic acid is attached via a glycosidic bond to the substance, and the resulting glucuronide, which has a much higher water solubility than the original substance, is eventually excreted by the kidneys. Acetaminophen glucuronide is found to be associated with beta-thalassemia, which is an inborn error of metabolism.
The excellent tolerability of therapeutic doses of paracetamol (acetaminophen) is a major factor in the very wide use of the drug. The major problem in the use of paracetamol is its hepatotoxicity after an overdose. Hepatotoxicity has also been reported after therapeutic doses, but critical analysis indicates that most patients with alleged toxicity from therapeutic doses have taken overdoses. Importantly, prospective studies indicate that therapeutic doses of paracetamol are an unlikely cause of hepatotoxicity in patients who ingest moderate to large amounts of alcohol (PMID: 15733027). Single doses of paracetamol are effective analgesics for acute postoperative pain and give rise to few adverse effects (PMID: 14974073). Acetaminophen (AAP) overdose and the resulting hepatotoxicity is an important clinical problem. In addition, AAP is widely used as a prototype hepatotoxin to study mechanisms of chemical-induced cell injury and to test the hepatoprotective potential of new drugs and herbal medicines. Because of its importance, the mechanisms of AAP-induced liver cell injury have been extensively investigated and controversially discussed for many years (PMID: 16863451).
trans-Aconitic acid, also known as trans-aconitate or (e)-aconitic acid, belongs to the class of organic compounds known as tricarboxylic acids and derivatives. These are carboxylic acids containing exactly three carboxyl groups. trans-Aconitic acid exists in all living species, ranging from bacteria to humans. trans-Aconitic acid is a dry, musty, and nut tasting compound. Outside of the human body, trans-aconitic acid has been detected, but not quantified in several different foods, such as garden tomato fruits, root vegetables, soy beans, and rices. trans-Aconitic acid is normally present in human urine, and it has been suggested that is present in larger amounts with Reye's syndrome and organic aciduria. trans-Aconitic acid in the urine is a biomarker for the consumption of soy products. trans-Aconitic acid is a substrate of enzyme trans-Aconitic acid 2-methyltransferase (EC2.1.1.144).
A compound composed of a two cyclic peptides attached to a phenoxazine that is derived from streptomyces parvullus. It binds to DNA and inhibits RNA synthesis (transcription), with chain elongation more sensitive than initiation, termination, or release. As a result of impaired mRNA production, protein synthesis also declines after dactinomycin therapy. (From AMA Drug Evaluations Annual, 1993, p2015)
Adenine is a purine base. Adenine is found in both DNA and RNA. Adenine is a fundamental component of adenine nucleotides. Adenine forms adenosine, a nucleoside, when attached to ribose, and deoxyadenosine when attached to deoxyribose; it forms adenosine triphosphate (ATP), a nucleotide, when three phosphate groups are added to adenosine. Adenosine triphosphate is used in cellular metabolism as one of the basic methods of transferring chemical energy between chemical reactions. Purine inborn errors of metabolism (IEM) are serious hereditary disorders, which should be suspected in any case of neonatal fitting, failure to thrive, recurrent infections, neurological deficit, renal disease, self-mutilation and other manifestations. Investigation usually starts with uric acid (UA) determination in urine and plasma. (OMIM 300322, 229600, 603027, 232400, 232600, 232800, 201450, 220150, 232200, 162000, 164050, 278300). (PMID: 17052198, 17520339).
Cyclic AMP (cAMP) or cyclic adenosine monophosphate is an adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. cAMP is found in all organisms ranging from bacteria to plants to animals. In humans and other mammals it is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon and ACTH. cAMP is synthesized from ATP by adenylate cyclase. Adenylate cyclase is located at the inner side of cell membranes. Adenylate cyclase is activated by the hormones glucagon and adrenaline and by G protein. Liver adenylate cyclase responds more strongly to glucagon, and muscle adenylate cyclase responds more strongly to adrenaline. cAMP decomposition into AMP is catalyzed by the enzyme phosphodiesterase. cAMP is primarily used for intracellular signal transduction, such as transferring into cells the effects of hormones like glucagon and adrenaline, which cannot pass through the plasma membrane. cAMP is also involved in the activation of protein kinases. In addition, cAMP binds to and regulates the function of ion channels such as the HCN channels. Hyperpolarization-activated cyclic nucleotide‚Äìgated (HCN) channels are integral membrane proteins that serve as nonselective voltage-gated cation channels in the plasma membranes of heart and brain cells. HCN channels are sometimes referred to as pacemaker channels because they help to generate rhythmic activity within groups of heart and brain cells.
Adenosine monophosphate, also known as 5'-adenylic acid and abbreviated AMP, is a nucleotide that is found in RNA. It is an ester of phosphoric acid with the nucleoside adenosine. AMP consists of the phosphate group, the pentose sugar ribose, and the nucleobase adenine. AMP can be produced during ATP synthesis by the enzyme adenylate kinase. AMP has recently been approved as a 'Bitter Blocker' additive to foodstuffs. When AMP is added to bitter foods or foods with a bitter aftertaste it makes them seem 'sweeter'. This potentially makes lower calorie food products more palatable.
Adenylic acid. Adenine nucleotide containing one phosphate group esterified to the sugar moiety in the 2'-, 3'-, or 5'-position. 3'-AMP has been identified in the human placenta (PMID: 32033212).
Adenosine is a nucleoside that is composed of adenine and D-ribose. Adenosine or adenosine derivatives play many important biological roles in addition to being components of DNA and RNA. For instance, adenosine plays an important role in energy transfer as adenosine triphosphate (ATP) and adenosine diphosphate (ADP). It also plays a role in signal transduction as cyclic adenosine monophosphate (cAMP). Adenosine itself is both a neurotransmitter and potent vasodilator. When administered intravenously adenosine causes transient heart block in the AV node. Due to the effects of adenosine on AV node-dependent supraventricular tachycardia, adenosine is considered a class V antiarrhythmic agent. Overdoses of adenosine intake (as a drug) can lead to several side effects including chest pain, feeling faint, shortness of breath, and tingling of the senses. Serious side effects include a worsening dysrhythmia and low blood pressure. When present in sufficiently high levels, adenosine can act as an immunotoxin and a metabotoxin. An immunotoxin disrupts, limits the function, or destroys immune cells. A metabotoxin is an endogenous metabolite that causes adverse health effects at chronically high levels. Chronically high levels of adenosine are associated with adenosine deaminase deficiency. Adenosine is a precursor to deoxyadenosine, which is a precursor to dATP. A buildup of dATP in cells inhibits ribonucleotide reductase and prevents DNA synthesis, so cells are unable to divide. Since developing T cells and B cells are some of the most mitotically active cells, they are unable to divide and propagate to respond to immune challenges. High levels of deoxyadenosine also lead to an increase in S-adenosylhomocysteine, which is toxic to immature lymphocytes.
Adipic acid is an important inudstrial dicarboxylic acid with about 2.5 billion kilograms produced per year. It is used mainly in the production of nylon. It occurs relatively rarely in nature. It has a tart taste and is also used as an additive and gelling agent in jello or gelatins. It is also used in some calcium carbonate antacids to make them tart. Adipic acid has also been incorporated into controlled-release formulation matrix tablets to obtain pH-independent release for both weakly basic and weakly acidic drugs. Adipic acid in the urine and in the blood is typically exogenous in origin and is a good biomarker of jello consumption. In fact, a condition known as adipic aciduria is actually an artifact of jello consumption (PMID: 1779643). However, certain disorders (such as diabetes and glutaric aciduria type I.) can lead to elevated levels of adipic acid snd other dicarboxcylic acids (such as suberic acid) in urine (PMID: 17520433; PMID: 6778884). Moreover, adipic acid is also found to be associated with 3-hydroxy-3-methylglutaryl-CoA lyase deficiency, carnitine-acylcarnitine translocase deficiency, malonyl-Coa decarboxylase deficiency, and medium Chain acyl-CoA dehydrogenase deficiency, which are inborn errors of metabolism. Adipic acid is also microbial metabolite found in Escherichia.
The ATP-dependent carboxylate-amine/thiol ligase superfamily is known to contain enzymes catalyzing the formation of various types of peptide, one of which is d-alanyl-d-alanine.(PMID: 16030213). The glycopeptide antibiotic vancomycin acts by binding to the D-alanyl-D-alanine terminus of the cell wall precursor lipid II in the cytoplasmic membrane.(PMID: 17418637). D-alanine-D-alanine ligase from Thermotoga maritima ATCC 43589 (TmDdl) was a useful biocatalyst for synthesizing D-amino acid dipeptides.D-Alanine-D-alanine ligase (Ddl) catalyzes the biosynthesis of an essential bacterial peptidoglycan precursor D-alanyl-D-alanine and it represents an important target for development of new antibacterial drugs. (PMID: 17267218). D-Alanyl-D-alanine is a microbial metabolite.
Alanylisoleucine is a dipeptide composed of alanine and isoleucine. It is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis.
Alanylvaline is a dipeptide composed of alanine and valine. It is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis.
Albendazole is only found in individuals that have used or taken this drug. It is a benzimidazole broad-spectrum anthelmintic structurally related to mebendazole that is effective against many diseases. (From Martindale, The Extra Pharmacopoeia, 30th ed, p38)Albendazole causes degenerative alterations in the tegument and intestinal cells of the worm by binding to the colchicine-sensitive site of tubulin, thus inhibiting its polymerization or assembly into microtubules. The loss of the cytoplasmic microtubules leads to impaired uptake of glucose by the larval and adult stages of the susceptible parasites, and depletes their glycogen stores. Degenerative changes in the endoplasmic reticulum, the mitochondria of the germinal layer, and the subsequent release of lysosomes result in decreased production of adenosine triphosphate (ATP), which is the energy required for the survival of the helminth. Due to diminished energy production, the parasite is immobilized and eventually dies.
Salbutamol is a short-acting, selective beta2-adrenergic receptor agonist used in the treatment of asthma and COPD. It is 29 times more selective for beta2 receptors than beta1 receptors giving it higher specificity for pulmonary beta receptors versus beta1-adrenergic receptors located in the heart. Salbutamol is formulated as a racemic mixture of the R- and S-isomers. The R-isomer has 150 times greater affinity for the beta2-receptor than the S-isomer and the S-isomer has been associated with toxicity. This lead to the development of levalbuterol, the single R-isomer of salbutamol. However, the high cost of levalbuterol compared to salbutamol has deterred wide-spread use of this enantiomerically pure version of the drug. Salbutamol is generally used for acute episodes of bronchospasm caused by bronchial asthma, chronic bronchitis and other chronic bronchopulmonary disorders such as chronic obstructive pulmonary disorder (COPD). It is also used prophylactically for exercise-induced asthma
Alfuzosin is only found in individuals that have used or taken this drug. It is an alpha-adrenergic blocker used to treat benign prostatic hyperplasia (BPH). It works by relaxing the muscles in the prostate and bladder neck, making it easier to urinate. [Wikipedia]Alfuzosin is a non-subtype specific alpha(1)-adrenergic blocking agent that exhibits selectivity for alpha(1)-adrenergic receptors in the lower urinary tract. Inhibition of these adrenoreceptors leads to the relaxation of smooth muscle in the bladder neck and prostate, resulting in the improvement in urine flow and a reduction in symptoms in benign prostate hyperplasia. Alfuzosin also inhibits the vasoconstrictor effect of circulating and locally released catecholamines (epinephrine and norepinephrine), resulting in peripheral vasodilation.
Allantoic acid is the end product of Allantoicase [EC:3.5.3.4], an enzyme involved in uric acid degradation (Purine metabolism). Although it is commonly accepted that allantoicase is lost in mammals, it has been identified in mice and humans. (PMID 11852104). A crystalline, transparent, colorless substance found in the allantoic liquid of the fetal calf. It was formerly called allantoic acid and amniotic acid.
Allantoin is a diureide of glyoxylic acid with the chemical formula C4H6N4O3. It is also called 5-ureidohydantoin or glyoxyldiureide. It is a product of the oxidation of uric acid. It is also a product of purine metabolism in most mammals except for higher apes, and it is present in their urine. In humans, uric acid is excreted instead of allantoin. The presence of allantoin in the urine can be an indication of microbial overgrowth or it can be created via non-enzymatic means through high levels of reactive oxygen species. In this regard, allantoin is sometimes used as a marker of oxidative stress. Allantoin can be isolated from cow urine or as a botanical extract of the comfrey plant. It has long been used for its healing, soothing, and anti-irritating properties. Allantoin helps to heal wounds and skin irritations and stimulates the growth of healthy tissue. Allantoin can be found in anti-acne products, sun care products, and clarifying lotions because of its ability to help heal minor wounds and promote healthy skin. Allantoin is frequently present in toothpaste, mouthwash, and other oral hygiene products as well as in shampoos, lipsticks, various cosmetic lotions and creams, and other cosmetic and pharmaceutical products. It is also a metabolite of Bacillus (PMID: 18302748) and Streptomyces (PMID: 24292080).
Allyl isothiocyanate is a volatile organic compound. Allyl isothiocyanate (AITC) is a constituent of mustard, horseradish and wasabi and certain vegetables found in the human diet, mostly in cruciferous vegetables. AITC is a colorless to pale yellow liquid that is slightly soluble in water, but soluble in most organic solvents. AITC possesses numerous biochemical and physiological activities. It is cytotoxic and tumorigenic at high doses and is also a modulator of enzymes involved in metabolism of xenobiotics, including carcinogens. It is plausible that the wide consumption of dietary AITC may have profound effects on human health. oxidative DNA damage may play important roles in carcinogenic processes induced by AITC. Allergic contact dermatitis from AICT is well known but infrequently reported. AITC is occasionally found as a volatile component of normal human biofluids. (PMID:5556886, 8222057, 8000299, 10754276, 15373848).
Alpha-Hydroxyhippuric acid, also known as alpha-hydroxybenzoylglycine or a-hydroxyhippate, belongs to the class of organic compounds known as hippuric acids. Hippuric acids are compounds containing hippuric acid, which consists of a of a benzoyl group linked to the N-terminal of a glycine. Alpha-Hydroxyhippuric acid (or Benzamidohydroxyacetic acid) is a carboxylic acid occasionally present in human biofluids. Alpha-hydroxyhippuric acid should not be confused with 2-hydroxyhippuric acid. It is used in the formulation of some herbicides and inks to enhance their action (Patents US 1996-657134, US 1975-627965). It is a substrate for the enzyme peptidyl-alpha-hydroxyglycine alpha-amidating lyase. Alpha-Hydroxyhippuric acid (or Benzamidohydroxyacetic acid) is a hippuric acid derivative that is occasionally present in human biofluids.
2-oxo-4-methylthiobutanoate, also known as 2-keto-4-methylthiobutyric acid, 2-keto-4-methylthiobutyrate or 4-(methylsulfanyl)-2-oxobutanoic acid, is a member of the class of compounds known as thia- fatty acids. Thia-fatty acids are fatty acid derivatives obtained by insertion of a sulfur atom at specific positions in the chain. Thus, 2-oxo-4-methylthiobutanoate is a fatty acid lipid molecule. 2-oxo-4-methylthiobutanoate is slightly soluble (in water) and a weakly acidic compound (based on its pKa). 2-oxo-4-methylthiobutanoate can be synthesized from L-methionine and butyric acid. 2-oxo-4-methylthiobutanoate can also be synthesized into S-adenosyl-4-methylthio-2-oxobutanoic acid. 2-oxo-4-methylthiobutanoate can be found in a number of food items such as cloves, highbush blueberries, common beets, and cashew nuts. 2-oxo-4-methylthiobutanoate can be found in urine. Within the cell, 2-oxo-4-methylthiobutanoate is primarily located in the cytoplasm and in the membrane. 2-oxo-4-methylthiobutanoate has been found in all living species, from bacteria to humans. In humans, 2-oxo-4-methylthiobutanoate is found to be involved in several metabolic disorders, some of those are S-adenosylhomocysteine (SAH) hydrolase deficiency, methylenetetrahydrofolate reductase deficiency (MTHFRD), methionine adenosyltransferase deficiency, and glycine N-methyltransferase deficiency. 4-Methylthio-2-oxobutanoic acid is the direct precursor of methional, which is a potent inducer of apoptosis in a BAF3 murine lymphoid cell line which is interleukin-3 (IL3)-dependent (PMID: 7848263).
A pyrazine compound inhibiting sodium reabsorption through sodium channels in renal epithelial cells. This inhibition creates a negative potential in the luminal membranes of principal cells, located in the distal convoluted tubule and collecting duct. Negative potential reduces secretion of potassium and hydrogen ions. Amiloride is used in conjunction with diuretics to spare potassium loss. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p705)
Anagrelide is only found in individuals that have used or taken this drug. It is a drug used for the treatment of essential thrombocytosis (ET; essential thrombocythemia). It also has been used in the treatment of chronic myeloid leukemia. [Wikipedia]The mechanism by which anagrelide reduces blood platelet count is still under investigation. Studies in patients support a hypothesis of dose-related reduction in platelet production resulting from a decrease in megakaryocyte hypermaturation. In blood withdrawn from normal volunteers treated with anagrelide, a disruption was found in the postmitotic phase of megakaryocyte development and a reduction in megakaryocyte size and ploidy. At therapeutic doses, anagrelide does not produce significant changes in white cell counts or coagulation parameters, and may have a small, but clinically insignificant effect on red cell parameters. Anagrelide inhibits cyclic AMP phosphodiesterase III (PDEIII). PDEIII inhibitors can also inhibit platelet aggregation. However, significant inhibition of platelet aggregation is observed only at doses of anagrelide higher than those required to reduce platelet count.
Aprobarbital is a barbiturate derivative synthesized in the 1920s by Ernst Preiswerk. It has sedative, hypnotic and anticonvulsant properties, and was used primarily for the treatment of insomnia. Aprobarbital was never as widely used as more common barbiturate derivatives such as phenobarbital and is now rarely prescribed.
D-Arabitol is a polyol. Polyols are sugar alcohols linked to the pentose phosphate pathway (PPP). They are classified on the basis of the number of carbon atoms. Polyols occur in body fluids. A patient with leukoencephalopathy and peripheral neuropathy has been identified as suffering from ribose-5-phosphate isomerase (RPI) deficiency, a defect in the PPP. In this disorder, highly elevated concentrations of the C5 polyols such as D-arabitol are found in body fluids. In addition, transaldolase deficiency, another defect in the PPP, has been diagnosed in a patient with mainly liver problems among others. This patient had increased concentrations of polyols, mainly D-arabitol. So far, the pathophysiological role of polyols is relatively unknown. It is thought that D-arabitol is a metabolic end-product in humans. The strong brain-CSF-plasma gradient of polyols in the patient with RPI deficiency suggested a primary metabolic disorder. The mechanisms of brain and neuronal damage in RPI deficiency remain to be elucidated. A neurotoxic effect due to the accumulation of the polyols may play a role. D-Arabitol is a product of the enzyme D-arabinitol 4-dehydrogenase (EC 1.1.1.11) in the pentose and glucuronate interconversion pathway (PMID: 16435225, J Inherit Metab Dis. 2005;28(6):1181-3). D-Arabitol has also been found to be a fungal metabolite, urinary D-Arabinitol is a marker for invasive candidiasis or infection by Candida fungal species (PMID: 15183861; PMID: 10647119). It can also a metabolite in Debaryomyces, Pichia and Zygosaccharomyces (PMID: 25809659).
Arbutin is found in apple. Glucoside in pear leaves (Pyrus communis
Ascorbic acid is found naturally in citrus fruits and many vegetables and is an essential nutrient in human diets. It is necessary to maintain connective tissue and bone. The biologically active form of ascorbic acid is vitamin C. Vitamin C is a water soluble vitamin. Primates (including humans) and a few other species in all divisions of the animal kingdom, notably the guinea pig, have lost the ability to synthesize ascorbic acid and must obtain it in their food. Vitamin C functions as a reducing agent and coenzyme in several metabolic pathways. Vitamin C is considered an antioxidant (PubChem). Ascorbic acid is an electron donor for enzymes involved in collagen hydroxylation, biosynthesis of carnitine and norepinephrine, tyrosine metabolism, and amidation of peptide hormones. Ascrobic acid (vitamin C) deficiency causes scurvy. The amount of vitamin C necessary to prevent scurvy may not be adequate to maintain optimal health. The ability of vitamin C to donate electrons also makes it a potent water-soluble antioxidant that readily scavenges free radicals such as molecular oxygen, superoxide, hydroxyl radical, and hypochlorous acid. In this setting, several mechanisms could account for a link between vitamin C and heart disease. One is the relation between LDL oxidation and vitamins C and E. Vitamin C in vitro can recycle vitamin E, which can donate electrons to prevent LDL oxidation in vitro. As the lipid-phase vitamin E is oxidized, it can be regenerated by aqueous vitamin C. Other possibilities are that vitamin C could decrease cholesterol by mechanisms not well characterized, or could improve vasodilatation and vascular reactivity, perhaps by decreasing the interactions of nitric oxide with oxidants (PMID: 10799361). Moreover, ascorbic acid is found to be associated with hyperoxalemia, which is an inborn error of metabolism. Ascorbic acid is also a microbial metabolite produced by Ketogulonicigenium (PMID: 15785002).
Aspartyl-Glutamate is a dipeptide composed of aspartate and glutamate. It is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis. This dipeptide has not yet been identified in human tissues or biofluids and so it is classified as an 'Expected' metabolite.
Aspartylphenylalanine is a dipeptide composed of aspartate and phenylalanine, and is a metabolic byproduct of its methyl ester, aspartame (Nutrasweet). After hydrolysis of the ester bond in the intestinal lumen, the dipeptide is apparently absorbed and digested in the same manner as dipeptides derived from protein digestion. There are several Asp-Phe dipeptidases that degrade this peptide. It has been suggested that individuals with aspartame allergies may be deficient in this peptidase (PMID: 3743970). It has been observed that N-beta-aspartylphenylalanine (a breakdown product of Asp-Phe) is a naturally occurring peptide found in both blood and urine (PMID: 2723819).
Benazepril, brand name Lotensin, is a medication used to treat high blood pressure (hypertension), congestive heart failure, and chronic renal failure. Upon cleavage of its ester group by the liver, benazepril is converted into its active form benazeprilat, a non-sulfhydryl angiotensin-converting enzyme (ACE) inhibitor.
Benzbromarone (INN) is a uricosuric agent used in the treatment of gout, especially when allopurinol, a first-line treatment, fails or produces intolerable adverse effects. It is structurally related to the antiarrhythmic amiodarone. Benzbromarone is a very potent inhibitor of CYP2C9. Several analogues of the drug have been developed as CYP2C9 and CYP2C19 inhibitors for use in research.
Benzoic acid, C6H5COOH, is a colourless crystalline solid and the simplest aromatic carboxylic acid. Benzoic acid occurs naturally free and bound as benzoic acid esters in many plant and animal species. Appreciable amounts have been found in most berries (around 0.05%). Cranberries contain as much as 300-1300 mg free benzoic acid per kg fruit. Benzoic acid is a fungistatic compound that is widely used as a food preservative. It often is conjugated to glycine in the liver and excreted as hippuric acid. Benzoic acid is a byproduct of phenylalanine metabolism in bacteria. It is also produced when gut bacteria process polyphenols (from ingested fruits or beverages). It can be found in Serratia (PMID:23061754).
Benzyl acetate, also known as benzyl ethanoate or fema 2135, belongs to the class of organic compounds known as benzyloxycarbonyls. These are organic compounds containing a carbonyl group substituted with a benzyloxyl group. Benzyl acetate is a sweet, apple, and apricot tasting compound. Benzyl acetate is found, on average, in the highest concentration within sweet basils. Benzyl acetate has also been detected, but not quantified, in several different foods, such as figs, fruits, pomes, tea, and alcoholic beverages. On high concnetrations benzyl acetate is a potentially toxic compound. If the compound has entered the eyes, they should be washed with large quantities of isotonic saline or water.
L-3-Cyanoalanine, also known as L-beta-cyanoalanine, belongs to the class of organic compounds known as L-alpha-amino acids. These are alpha-amino acids which have the L-configuration of the alpha-carbon atom. L-3-Cyanoalanine is a very strong basic compound (based on its pKa). L-3-Cyanoalanine exists in all living organisms, ranging from bacteria to humans. Outside of the human body, L-3-cyanoalanine has been detected, but not quantified in, several different foods, such as summer savouries, orange bell peppers, red rices, mixed nuts, and green bell peppers. This could make L-3-cyanoalanine a potential biomarker for the consumption of these foods.
Bicalutamide is only found in individuals that have used or taken this drug. It is an oral non-steroidal anti-androgen for prostate cancer. It binds to the androgen receptor.Bicalutamide competes with androgen for the binding of androgen receptors, consequently blocking the action of androgens of adrenal and testicular origin which stimulate the growth of normal and malignant prostatic tissue.
Butabarbital (trade name Butisol) is a prescription barbiturate sleep aid. Butabarbital has a particularly fast onset of effects and short duration of action compared to other barbiturates, which makes it useful for certain applications such as treating severe insomnia and relieving anxiety before surgical procedures; however it is also relatively dangerous particularly when combined with alcohol, and so is now rarely used, although it is still prescribed in some Eastern European and South American countries. Its short duration of action gives butabarbital a high abuse potential, comparable to secobarbital. [Wikipedia]
N-Butyrylglycine is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism, such as ethylmalonic encephalopathy. In certain cases the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acyl glycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13), which is an enzyme that catalyzes the chemical reaction: acyl-CoA + glycine < -- > CoA + N-acylglycine amino acids composed of glycine substituted at the nitrogen rather than the usual carbon position, resulting in the loss of hydrogen bonding donors. Polymers of these compounds are called Peptoids.
Caffeic acid (CAS: 331-39-5) is a polyphenol present in normal human urine positively correlated to coffee consumption and influenced by the dietary intake of diverse types of food (PMID:16870009). Caffeic acid has been found to be a microbial metabolite of Escherichia (PMID: 28396925).
L-Canavanine, a non-protein amino acid of certain leguminous plants, is related structurally to the protein amino acid, L-arginine. Canavanine is accumulated primarily in the seeds where it serves both as a defensive compound against herbivores and a vital source of nitrogen for the growing embryo. Organisms that consume it can mistakenly incorporate it into their own proteins, in the place of arginine thereby producing structurally aberrant proteins that may not function properly or not at all. Some specialized herbivores tolerate L-canavanine either because they metabolize it efficiently or avoid its incorporation into their own nascent proteins.
Carboxy-ibuprofen is a metabolite of ibuprofen. Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) used for relief of symptoms of arthritis, fever, as an analgesic (pain reliever), especially where there is an inflammatory component, and dysmenorrhea. Ibuprofen is known to have an antiplatelet effect, though it is relatively mild and somewhat short-lived when compared with aspirin or other better-known antiplatelet drugs. (Wikipedia)
Carvedilol is only found in individuals that have used or taken this drug. It is a non-selective beta blocker indicated in the treatment of mild to moderate congestive heart failure (CHF).Carvedilol is a racemic mixture in which nonselective beta-adrenoreceptor blocking activity is present in the S(-) enantiomer and alpha-adrenergic blocking activity is present in both R(+) and S(-) enantiomers at equal potency. Carvedilol's beta-adrenergic receptor blocking ability decreases the heart rate, myocardial contractility, and myocardial oxygen demand. Carvedilol also decreases systemic vascular resistance via its alpha adrenergic receptor blocking properties. Carvedilol and its metabolite BM-910228 (a less potent beta blocker, but more potent antioxidant) have been shown to restore the inotropic responsiveness to Ca<sup>2+</sup> in OH<sup>-</sup> free radical-treated myocardium. Carvedilol and its metabolites also prevent OH<sup>-</sup> radical-induced decrease in sarcoplasmic reticulum Ca<sup>2+</sup>-ATPase activity. Therefore, carvedilol and its metabolites may be beneficial in chronic heart failure by preventing free radical damage.
Pyrocatechol, often known as catechol or benzene-1,2-diol, is a benzenediol, with formula C6H4(OH)2. It was first prepared in 1839 by H. Reinsch by distilling catechin (the juice of Mimosa catechu). This colourless compound occurs naturally, but about 20000 tons are manufactured each year, mainly as precursors to pesticides, flavors, and fragrances. Its sulfonic acid is often present in the urine of many mammals. Small amounts of catechol occur naturally in fruits and vegetables, along with the enzyme polyphenol oxidase. Upon mixing the enzyme with the substrate and exposure to oxygen (as when a potato or apple is cut), the colorless catechol oxidizes to reddish-brown benzoquinone derivatives. The enzyme is inactivated by adding an acid, such as lemon juice, or by refrigeration. Excluding oxygen also prevents the browning reaction. Catechol melts at 28 °C and boils at 250 °C. It is employed in medicine as an expectorant. The dimethyl ether or veratrol is also used in medicine. Many other pyrocatechin derivatives have been suggested for therapeutic application. Pyrocatechol has also been found to be a microbial metabolite in Escherichia, Mycobacterium and Pseudomonas (PMID:19300498; PMID:25281236).
Cefaclor is only found in individuals that have used or taken this drug. It is a semisynthetic, broad-spectrum antibiotic derivative of cephalexin. [PubChem]Cefaclor, like the penicillins, is a beta-lactam antibiotic. By binding to specific penicillin-binding proteins (PBPs) located inside the bacterial cell wall, it inhibits the third and last stage of bacterial cell wall synthesis. Cell lysis is then mediated by bacterial cell wall autolytic enzymes such as autolysins. It is possible that cefaclor interferes with an autolysin inhibitor.
Cefdinir (marketed by Abbott Laboratories under the brand name Omnicef) is a semi-synthetic, broad-spectrum antibiotic in the third generation of the cephalosporin class, proven effective for common bacterial infections of the ear, sinus, throat, and skin. It was approved by the U.S. Food and Drug Administration (FDA) in December of 1997.
Cefixime, an antibiotic, is a third-generation cephalosporin like ceftriaxone and cefotaxime. Cefixime is highly stable in the presence of beta-lactamase enzymes. As a result, many organisms resistant to penicillins and some cephalosporins due to the presence of beta-lactamases, may be susceptible to cefixime. The antibacterial effect of cefixime results from inhibition of mucopeptide synthesis in the bacterial cell wall.
Cellobiose, also known as GLCB1-4GLCB or cellose, is a disaccharide. It is also classified as a reducing sugar. In terms of its chemical structure, it is derived from the condensation of a pair beta-glucose molecules creating a beta (1‚Üí4) bond. It belongs to the class of organic compounds known as O-glycosyl compounds. These are glycosides in which a sugar group is bonded through one carbon to another group via a O-glycosidic bond. Cellobiose can be obtained by enzymatic hydrolysis of cellulose and cellulose-rich materials such as cotton, jute, or paper. Cellobiose is a plant metabolite found in flowering plants, conifers and other gymnosperms. Cellobiose can also be found in vertebrates that have consumed plant foods. It has been detected, but not quantified in, several different foods, such as okra, common chokecherries, cherry tomatoes, and welsh onions. Cellobiose can be used as an indicator carbohydrate for Crohn's disease and malabsorption syndrome. Intestinal permeability to detect Crohn's disease and malabsorption syndrome can be measured by the sugar absorption test. This test is based on determining the ratio of the urinary excretion of a large (a disaccharide such as cellobiose) and a small carbohydrate (a monosaccharide such as lactulose or rhamnose) after oral administration. Patients with Crohn's disease or with ulcerative colitis have increased permeability indices in comparison to healthy controls (PMID: 15546811).
Cellobiose, also known as GLCB1-4GLCB or cellose, is a disaccharide. It is also classified as a reducing sugar. In terms of its chemical structure, it is derived from the condensation of a pair beta-glucose molecules creating a beta (1‚Üí4) bond. It belongs to the class of organic compounds known as O-glycosyl compounds. These are glycosides in which a sugar group is bonded through one carbon to another group via a O-glycosidic bond. Cellobiose can be obtained by enzymatic hydrolysis of cellulose and cellulose-rich materials such as cotton, jute, or paper. Cellobiose is a plant metabolite found in flowering plants, conifers and other gymnosperms. Cellobiose can also be found in vertebrates that have consumed plant foods. It has been detected, but not quantified in, several different foods, such as okra, common chokecherries, cherry tomatoes, and welsh onions. Cellobiose can be used as an indicator carbohydrate for Crohn's disease and malabsorption syndrome. Intestinal permeability to detect Crohn's disease and malabsorption syndrome can be measured by the sugar absorption test. This test is based on determining the ratio of the urinary excretion of a large (a disaccharide such as cellobiose) and a small carbohydrate (a monosaccharide such as lactulose or rhamnose) after oral administration. Patients with Crohn's disease or with ulcerative colitis have increased permeability indices in comparison to healthy controls (PMID: 15546811).
Chlorogenic acid is an ester of caffeic acid and quinic acid. Chlorogenic acid is the major polyphenolic compound in coffee, isolated from the leaves and fruits of dicotyledonous plants. This compound, long known as an antioxidant, also slows the release of glucose into the bloodstream after a meal. Coffee is a complex mixture of chemicals that provides significant amounts of chlorogenic acid. The chlorogenic acid content of a 200 ml (7-oz) cup of coffee has been reported to range from 70-350 mg, which would provide about 35-175 mg of caffeic acid. The results of epidemiological research suggest that coffee consumption may help prevent several chronic diseases, including type 2 diabetes mellitus, Parkinson's disease and liver disease (cirrhosis and hepatocellular carcinoma). Most prospective cohort studies have not found coffee consumption to be associated with significantly increased cardiovascular disease risk. However, coffee consumption is associated with increases in several cardiovascular disease risk factors, including blood pressure and plasma homocysteine. At present, there is little evidence that coffee consumption increases the risk of cancer. (PMID:16507475, 17368041).
A renal dehydropeptidase-I and leukotriene D4 dipeptidase inhibitor. Since the antibiotic, imipenem, is hydrolyzed by dehydropeptidase-I, which resides in the brush border of the renal tubule, cilastatin is administered with imipenem to increase its effectiveness. The drug also inhibits the metabolism of leukotriene D4 to leukotriene E4. [PubChem]
trans-Cinnamic acid, also known as (e)-cinnamic acid or phenylacrylic acid, belongs to the class of organic compounds known as cinnamic acids. These are organic aromatic compounds containing a benzene and a carboxylic acid group forming 3-phenylprop-2-enoic acid. trans-Cinnamic acid exists in all living species, ranging from bacteria to humans. trans-Cinnamic acid is a sweet, balsam, and cinnamon tasting compound. Outside of the human body, trans-Cinnamic acid is found, on average, in the highest concentration within a few different foods, such as chinese cinnamons, olives, and lingonberries and in a lower concentration in redcurrants, red raspberries, and corianders. trans-Cinnamic acid has also been detected, but not quantified in several different foods, such as common oregano, pepper (spice), fennels, pomegranates, and european cranberries. This could make trans-cinnamic acid a potential biomarker for the consumption of these foods. Cinnamic acid has been shown to be a microbial metabolite; it can be found in Alcaligenes, Brevibacterium, Cellulomonas, and Pseudomonas (PMID:16349793). trans-Cinnamic acid is a potentially toxic compound.
Citraconic acid, also known as 2-methylmaleate or methylmaleic acid, belongs to the class of organic compounds known as methyl-branched fatty acids. These are fatty acids with an acyl chain that has a methyl branch. Usually, they are saturated and contain only one or more methyl group. However, branches other than methyl may be present. Citraconic acid is a dicarboxylic acid consisting of maleic acid having a methyl substituent at the 2-position. Citraconic acid exists as a white solid. It is the cis-isomer of mesaconic acid and is one of the pyrocitric acids formed upon the heating of citric acid.  Citraconic acid has been detected in the urine of both normal and fasting individuals (PMID: 6778884). Citraconic acid is also elevated in the urine of individuals with methylmalonic acidaemia who have suffered ketotic attacks (PMID: 116077).  Altered serum levels of citraconic acid have been detected in patients with primary biliary cholangitis (PMID: 28400566).
Citramalic acid, also known as 2-Methylmalic acid, is an analog of malic acid. The structure of citramalic acid is similar to the structure of malic acid except it has an extra CH3 group on position 2. It is also classified as a 2-hydroxydicarboxylic acid. Citramalic acid exists in two isomers, L-citramalic acid and D-citramalic acid.  The L-isomer is more biologically relevant isomer. Citramalic acid is found in almost all living organisms from microbes to plants to humans although citramalate is primarily produced from bacteria. L-citramalic acid was first isolated from the peel of apples in 1954 (PMID: 13160011). It has also been isolated in wine and other ripening fruit (PMID: 13807713). Citramalic acid can inhibit the production of malic acid. Citramalic acid is also an important microbial metabolite and has been found to be a byproduct of Saccharomyces yeast species, as well as Propionibacterium acnes and Aspergillus niger (PMID: 31827810) (http://drweyrich.weyrich.com/labs/oat.html) (PMID: 7628083). Citramalic acid is a component of the C5-branched dibasic acid metabolism pathway. It can be broken down by the enzyme citramalate lyase, which converts citramalate to acetate and pyruvate. Citramalate synthase is an enzyme found in bacteria that synthesizes citramalic acid from acetyl-CoA, pyruvate and water. Citramalic acid may have a useful role in medical diagnoses. It has been found in the urine of two brothers with autistic features (PMID: 7628083). Citramalic acid can also be used as a urinary marker for gut dysbiosis (PMID: 31669633). Dysbiosis is a disorder of the bacterial flora of the human digestive tract. It is usually diagnosed clinically by direct detection of an abnormal pattern of the intestinal microbiota.
Cladribine is only found in individuals that have used or taken this drug. It is an antineoplastic agent used in the treatment of lymphoproliferative diseases including hairy-cell leukemia. [PubChem]Cladribine is structurally related to fludarabine and pentostatin but has a different mechanism of action. Although the exact mechanism of action has not been fully determined, evidence shows that cladribine is phosphorylated by deoxycytidine kinase to the nucleotidecladribine triphosphate (CdATP; 2-chloro-2â€²-deoxyadenosine 5â€²-triphosphate), which accumulates and is incorporated into DNA in cells such as lymphocytes that contain high levels of deoxycytidine kinase and low levels of deoxynucleotidase, resulting in DNA strand breakage and inhibition of DNA synthesis and repair. High levels of CdATP also appear to inhibit ribonucleotide reductase, which leads to an imbalance in triphosphorylated deoxynucleotide (dNTP) pools and subsequent DNA strand breaks, inhibition of DNA synthesis and repair, nicotinamide adenine dinucleotide (NAD) and ATP depletion, and cell death. Unlike other antimetabolite drugs, cladribine has cytotoxic effects on resting as well as proliferating lymphocytes. However, it does cause cells to accumulate at the G1/S phase junction, suggesting that cytotoxicity is associated with events critical to cell entry into S phase. It also binds purine nucleoside phosphorylase (PNP), however no relationship between this binding and a mechanism of action has been established.
3-Carboxy-4-methyl-5-propyl-2-furanpropionic acid (CMPF) is also called 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid and 2-(2-carboxyethyl)-4-methyl-4-propylfuran-3-carboxylic acid. CMPF is significantly accumulated in the serum of chronic kidney disease patients and is considered to be a potent uremic toxin (PMID: 8734460) and identified as a uremic toxin according to the European Uremic Toxin Working Group (PMID: 22626821). There are several minor derivatives of CMPF that have been detected in serum and urine including 3-carboxy-4-methyl-5-pentyl-2-furanpropionic acid, 3-carboxy-4-methyl-5-ethyl-2-furanpropionic acid, and 3-carboxy-5-propyl-2-furanpropionic acid. CMPF was first detected in human urine in 1979 (PMID: 12388676) and it is believed to be formed from the consumption of fish, vegetables, and fruits (PMID: 19083276 ; PMID: 12388676). CMPF is a strong inhibitor of mitochondrial respiration and is associated with thyroid dysfunction (PMID: 19083276). CMPF also directly inhibits renal secretion of various drugs and endogenous organic acids by competitively inhibiting OAT3 transporters (PMID: 11967025). It is also thought to contribute to various neurological abnormalities because it inhibits the transport of organic acids at the blood-brain barrier (PMID: 12388676). 
Coniferaldehyde (CAS: 458-36-6), also known as 4-hydroxy-3-methoxycinnamaldehyde or ferulaldehyde, belongs to the class of organic compounds known as methoxyphenols. Methoxyphenols are compounds containing a methoxy group attached to the benzene ring of a phenol moiety. Coniferaldehyde is an extremely weak basic (essentially neutral) compound (based on its pKa). Outside of the human body, coniferaldehyde is found, on average, in the highest concentration within sherries. Coniferaldehyde has also been detected, but not quantified in, several different foods, such as highbush blueberries, lima beans, Chinese cabbages, loquats, and greenthread tea. This could make coniferaldehyde a potential biomarker for the consumption of these foods. BioTransformer predicts that coniferaldehyde is a product of caffeic aldehyde metabolism via a catechol-O-methylation-pattern2 reaction catalyzed by the enzyme catechol O-methyltransferase (PMID: 30612223).
Cortisone is a naturally occurring glucocorticoid. It has been used in replacement therapy for adrenal insufficiency and as an anti-inflammatory agent. Cortisone itself is inactive. It is converted in the liver into the active metabolite cortisol. Cortisone is a corticosteroid hormone released by the adrenal gland in response to stress. One of cortisone's effects on the body, and a potentially harmful side effect when administered clinically, is the suppression of the immune system. This is an explanation for the apparent correlation between high stress and sickness.
Cortexolone, also known as cortodoxone or 11-deoxycortisol, belongs to the class of organic compounds known as 21-hydroxysteroids. These are steroids carrying a hydroxyl group at the 21-position of the steroid backbone. Thus, cortexolone is considered to be a steroid molecule. Cortexolone is an endogenous glucocorticoid steroid hormone, and a metabolic intermediate in the synthesis of cortisol. It was first described by Tadeusz Reichstein in 1938 and named as Substance S. It has also been referred to as Reichstein's Substance S or Compound S. Cortexolone acts as a glucocorticoid, though it is less potent than cortisol. Cortexolone is synthesized from 17Œ±-hydroxyprogesterone by 21-hydroxylase and is converted to cortisol by 11Œ≤-hydroxylase. As a result, the level of cortexolone is often measured in patients to diagnose impaired cortisol synthesis, to identify any enzyme deficiency that may be causing impairment along the pathway to cortisol, and to differentiate adrenal disorders. Cortexolone in mammals has limited biological activity and mainly acts as metabolic intermediate within the glucocorticoid pathway, leading to cortisol. On the other hand, in sea lampreys, cortexolone is the major glucocorticoid, with mineralocorticoid activity. Cortexolone in sea lampreys binds to specific corticosteroid receptors and is involved in intestinal osmoregulation and in sea lamprey at metamorphosis, a process in which they develop seawater tolerance before downstream migration.
Creatinine, or creatine anhydride, is a breakdown product of creatine phosphate in muscle. The loss of a water molecule from creatine results in the formation of creatinine. Creatinine is transferred to the kidneys by blood plasma, whereupon it is eliminated from the body by glomerular filtration and partial tubular excretion. Creatinine is usually produced at a fairly constant rate by the body. Measuring serum creatinine is a simple test and it is the most commonly used indicator of renal function. A rise in blood creatinine levels is observed only with marked damage to functioning nephrons. Therefore, this test is not suitable for detecting early kidney disease. The typical reference range for women is considered about 45-90 µmol/L; for men 60-110 µmol/L. Creatine and creatinine are metabolized in the kidneys, muscle, liver, and pancreas.
Cystathionine is a dipeptide formed by serine and homocysteine. Cystathioninuria is a prominent manifestation of vitamin-B6 deficiency. The transsulfuration of methionine yields homocysteine, which combines with serine to form cystathionine, the proximate precursor of cysteine through the enzymatic activity of cystathionase. In conditions in which cystathionine gamma-synthase or cystathionase is deficient, for example, there is cystathioninuria. Although cystathionine has not been detected in normal human serum or plasma by most conventional methods, gas chromatographic/mass spectrometric methodology detected a mean concentration of cystathionine in normal human serum of 140 nM, with a range of 65 to 301 nM. Cystathionine concentrations in CSF have been 10, 1, and 0.5 uM, and "not detected". Only traces (i.e., <1 uM) of cystathionine are present in normal CSF.587. Gamma-cystathionase deficiency (also known as Cystathioninuria), which is an autosomal recessive disorder (NIH: 2428), provided the first instance in which, in a human, the major biochemical abnormality due to a defined enzyme defect was clearly shown to be alleviated by administration of large doses of pyridoxine. The response in gamma-cystathionase-deficient patients is not attributable to correction of a preexisting deficiency of this vitamin (OMMBID, Chap. 88).
Cysteinesulfonic acid, also known as (2r)-2-amino-3-sulfopropanoic acid or 3-sulfoalanine, is a member of the class of compounds known as L-alpha-amino acids. L-alpha-amino acids are alpha amino acids which have the L-configuration of the alpha-carbon atom. Cysteinesulfonic acid is soluble (in water) and an extremely strong acidic compound (based on its pKa). Cysteinesulfonic acid can be found in a number of food items such as roman camomile, pili nut, chicory, and garden tomato, which makes cysteinesulfonic acid a potential biomarker for the consumption of these food products.
Cystine is an oxidized dimeric form of cysteine. It is formed by linking two cysteine residues via a disulfide bond (Cys-S-S-Cys) between the -SH groups. Cystine is found in high concentrations in digestive enzymes and in the cells of the immune system, skeletal and connective tissues, skin, and hair. Hair and skin are 10-14% cystine. Cystine is the preferred form of cysteine for the synthesis of glutathione in cells involved in the immune system (e.g. macrophages and astrocytes). Lymphocytes and neurons prefer cysteine for glutathione production. Optimizing glutathione levels in macrophages and astrocytes with cystine allows these cells to provide cysteine to lymphocytes and neurons directly upon demand (Wikipedia).
Cytarabine, or cytosine arabinoside, a pyrimidine nucleoside analog, is found in mushrooms. Cytarabine is isolated from the mushroom Xerocomus nigromaculatus of unknown palatability. Cytarabine is an antineoplastic anti-metabolite used in the treatment of several forms of leukemia including acute myelogenous leukemia and meningeal leukemia. Cytarabine is an antimetabolite antineoplastic agent that inhibits the synthesis of DNA. Its actions are specific for the S phase of the cell cycle to stop normal cell development and division. Cytarabine is metabolized intracellularly into its active triphosphate form (cytosine arabinoside triphosphate). This metabolite then damages DNA by multiple mechanisms, including the inhibition of alpha-DNA polymerase, inhibition of DNA repair through an effect on beta-DNA polymerase, and incorporation into DNA. The latter mechanism is probably the most important. Cytotoxicity is highly specific for the S phase of the cell cycle. Cytarabine is a chemotherapy agent used mainly in the treatment of hematological malignancies such as acute myeloid leukemia (AML) and non-Hodgkin lymphoma. It is also known as ara C. Cytosine arabinoside is an antimetabolic agent with the chemical name of 1 -arabinofuranosylcytosine. Its mode of action is due to its rapid conversion into cytosine arabinoside triphosphate, which damages DNA when the cell cycle holds in the S phase (synthesis of DNA). Rapidly dividing cells, which require DNA replication for mitosis, are therefore most affected. Cytosine arabinoside also inhibits both DNA and RNA polymerases and nucleotide reductase enzymes needed for DNA synthesis
Cytidine monophosphate, also known as 5'-cytidylic acid and abbreviated CMP, is a nucleotide. It is an ester of phosphoric acid with the nucleoside cytidine. CMP consists of the phosphate group, the pentose sugar ribose, and the nucleobase cytosine. Cytidine monophosphate (CMP) is derived from cytidine triphosphate (CTP) with subsequent loss of two phosphates. The synthesis of the pyrimidines CTP and UTP occurs in the cytoplasm and starts with the formation of carbamoyl phosphate from glutamine and CO2. Next, aspartate undergoes a condensation reaction with carbamoyl-phosphate to form orotic acid. In a subsequent cyclization reaction, the enzyme Aspartate carbamoyltransferase forms N-carbamoyl-aspartate which is converted into dihydroorotic acid by Dihydroorotase. The latter is converted to orotate by Dihydroorotate oxidase. Orotate is covalently linked with a phosphorylated ribosyl unit with Orotate phosphoribosyltransferase (aka "PRPP transferase") catalyzing reaction, yielding orotidine monophosphate (OMP). Orotidine-5-phosphate is decarboxylated by Orotidine-5'-phosphate decarboxylase to form uridine monophosphate (UMP). UMP is phosphorylated by two kinases to uridine triphosphate (UTP) via two sequential reactions with ATP. CTP is subsequently formed by amination of UTP by the catalytic activity of CTP synthetase. Cytosine monophosphate (CMP) and uridine monophosphate (UMP) have been prescribed for the treatment of neuromuscular affections in humans. Patients treated with CMP/UMP recover from altered neurological functions. Additionally, the administration of CMP/UMP appears to favour the entry of glucose in the muscle and CMP/UMP may be important in maintaining the level of hepatic glycogen constant during exercise. [PMID:18663991].
Cytidine is a nucleoside that is composed of the base cytosine linked to the five-carbon sugar D-ribose. Cytidine is a pyrimidine that besides being incorporated into nucleic acids, can serve as a substrate for the salvage pathway of pyrimidine nucleotide synthesis. It is a precursor of cytidine triphosphate (CTP) needed in the phosphatidylcholine (PC) and phosphatidylethanolamine (PE) biosynthetic pathways. These variations probably reflect the species differences in cytidine deaminase, the enzyme that converts cytidine to uridine in the body. The transport of cytidine into the brain's extracellular fluid, and then into neurons and glia, are essential prerequisites for cytidine to be utilized in the brain. An efficient mechanism mediating the brain uptake of circulating cytidine has not yet been demonstrated. The biosynthesis of PC, the most abundant phosphatide in the brain, via the Kennedy pathway requires phosphocholine and cytidine triphosphate (CTP), a cytidine nucleotide involved in the rate-limiting step. The enzyme that converts CTP to endogenous CDP-choline (CTP:phosphocholine cytidylyltransferase) is unsaturated at physiological brain CTP levels. APOBEC is a family of enzymes that has been discovered with the ability to deaminate cytidines on RNA or DNA. The human apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3G protein (APOBEC3G, or hA3G), provides cells with an intracellular antiretroviral activity that is associated with the hypermutation of viral DNA through cytidine deamination. Indeed, hA3G belongs to a family of vertebrate proteins that contains one or two copies of a signature sequence motif unique to cytidine deaminases (CTDAs) (PMID: 16769123, 15780864, 16720547).
Cytosine, also known as C, belongs to the class of organic compounds known as pyrimidones. Pyrimidones are compounds that contain a pyrimidine ring, which bears a ketone. Pyrimidine is a 6-membered ring consisting of four carbon atoms and two nitrogen centers at the 1- and 3- ring positions. Cytosine is also classified as a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached (an amine group at position 4 and a keto group at position 2). Cytosine is one of the four main bases found in DNA and RNA, along with adenine, guanine, and thymine (uracil in RNA). The nucleoside of cytosine is cytidine. In Watson-Crick base pairing, cytosine forms three hydrogen bonds with guanine. Cytosine was discovered and named by Albrecht Kossel and Albert Neumann in 1894 when it was hydrolyzed from calf thymus tissues. Cytosine exists in all living species, ranging from bacteria to plants to humans. Within cells, cytosine can undergo several enzymatic reactions. It can be methylated into 5-methylcytosine by an enzyme called DNA methyltransferase (DNMT) or be methylated and hydroxylated to make 5-hydroxymethylcytosine. The DNA methyltransferase (DNMT) family of enzymes transfer a methyl group from S-adenosyl-l-methionine (SAM) to the 5‚Äô carbon of cytosine in a molecule of DNA. High levels of cytosine can be found in the urine of individuals with severe combined immunodeficiency syndrome (SCID). Cytosine concentrations as high as (23-160 mmol/mol creatinine) were detected in SCID patients compared to normal levels of <2 mmol/mol creatinine (PMID: 262183).
Daidzein is one of several known isoflavones. Isoflavones compounds are found in a number of plants, but soybeans and soy products like tofu and textured vegetable protein are the primary food source. Up until recently, daidzein was considered to be one of the most important and most studied isoflavones, however more recently attention has shifted to isoflavone metabolites. Equol represents the main active product of daidzein metabolism, produced via specific microflora in the gut. The clinical effectiveness of soy isoflavones may be a function of the ability to biotransform soy isoflavones to the more potent estrogenic metabolite, equol, which may enhance the actions of soy isoflavones, owing to its greater affinity for estrogen receptors, unique antiandrogenic properties, and superior antioxidant activity. However, not all individuals consuming daidzein produce equol. Only approximately one-third to one-half of the population is able to metabolize daidzein to equol. This high variability in equol production is presumably attributable to interindividual differences in the composition of the intestinal microflora, which may play an important role in the mechanisms of action of isoflavones. But, the specific bacterial species in the colon involved in the production of equol are yet to be discovered. (PMID:18045128, 17579894). Daidzein is a biomarker for the consumption of soy beans and other soy products.
Dehydroepiandrosterone sulfate or DHEA-S is the sulfated form of dehydroepiandrosterone (DHEA). This sulfation is reversibly catalyzed by sulfotransferase 2A1 (SULT2A1) primarily in the adrenals, the liver, and small intestine. In the blood, most DHEA is found as DHEA-S with levels that are about 300 times higher than those of free DHEA. Orally-ingested DHEA is converted into its sulfate when passing through the intestines and liver. Whereas DHEA levels naturally reach their peak in the early morning hours, DHEAS levels show no diurnal variation. From a practical point of view, measurement of DHEA-S is preferable to DHEA since levels are more stable. DHEA (from which DHEA-S comes from) is a natural steroid prohormone produced from cholesterol by the adrenal glands, the gonads, adipose tissue, brain, and in the skin (by an autocrine mechanism). DHEA is the precursor of androstenedione, which can undergo further conversion to produce the androgen testosterone and the estrogens estrone and estradiol. DHEA is also a potent sigma-1 agonist. Serum dehydroepiandrosterone sulfate is a classic marker for adrenarche, and subsequently for the individual hormonal milieu (PMID: 10599744). Dehydroepiandrosterone sulfate is an endogenously produced sex steroid that has been hypothesized to have anti-aging effects (PMID: 16960027). It also has been inversely associated with the development of atherosclerosis (PMID: 8956025).
5-Hydroxylysine (Hyl), also known as hydroxylysine or 5-Hydroxy-L-lysine, belongs to the class of organic compounds known as L-alpha-amino acids. These are alpha amino acids which have the L-configuration of the alpha-carbon atom. Amino acids are organic compounds that contain amino (‚ÄìNH2) and carboxyl (‚ÄìCOOH) functional groups, along with a side chain (R group) specific to each amino acid. 5-Hydroxylysine is a hydroxylated derivative of the amino acid lysine that is present in certain collagens, the chief structural protein of mammalian skin and connective tissue. 5-Hydroxylysine arises from a post-translational hydroxy modification of lysine and is biosynthesized from lysine via oxidation by lysyl hydroxylase enzymes. 5-Hydroxylysine can then undergo further modification by glycosylation, giving rise to galactosyl hydroxylysine (GH) and glucosylgalactosyl hydroxylysine (GGH). These glycosylated forms of hydroxylysine contribute to collagen‚Äôs unusual toughness and resiliency. The monoglycosylated, galactosyl-hydroxylysine is enriched in bone compared with the disaccharide form, glucosyl-galactosyl-hydroxylysine, which is the major form in skin. 5-Hydroxylysine exists in all eukaryotes, ranging from yeast to humans. It was first discovered in 1921 by Donald Van Slyke. Free forms of hydroxylysine arise through proteolytic degradation of collagen.  Urinary excretion of 5-Hydroxylysine and its glycosides can be used as an index of collagen degradation, with high levels being indicative of more rapid or extensive collagen degradation (often seen in patients with thermal burns, Paget's disease of bone or hyperphosphatasia) (PMID: 404321).
Deoxyadenosine is a derivative of the nucleoside adenosine. It is composed of adenine attached to a deoxyribose moiety via a N9-glycosidic bond. Deoxyribose differs from ribose by the absence of oxygen in the 3' position of its ribose ring. Deoxyadenosine is a critical component of DNA. When present in sufficiently high levels, deoxyadensoine can act as an immunotoxin and a metabotoxin. An immunotoxin disrupts, limits the function, or destroys immune cells. A metabotoxin is an endogenous metabolite that causes adverse health effects at chronically high levels. Chronically high levels of deoxyadenosine are associated with adenosine deaminase (ADA) deficiency, an inborn error of metabolism. ADA deficiency damages the immune system and causes severe combined immunodeficiency (SCID). People with SCID lack virtually all immune protection from bacteria, viruses, and fungi. They are prone to repeated and persistent infections that can be very serious or life-threatening. These infections are often caused by "opportunistic" organisms that ordinarily do not cause illness in people with a normal immune system. The main symptoms of ADA deficiency are pneumonia, chronic diarrhea, and widespread skin rashes. The mechanism by which dATP functions as an immunotoxin is as follows: because deoxyadenosine is a precursor to dATP, a buildup of dATP in cells inhibits ribonucleotide reductase and prevents DNA synthesis, so cells are unable to divide. Since developing T cells and B cells are some of the most mitotically active cells, they are unable to divide and propagate to respond to immune challenges. High levels of deoxyadenosine also lead to an increase in S-adenosylhomocysteine, which is toxic to immature lymphocytes.
Deoxyuridine monophosphate (dUMP), also known as deoxyuridylic acid or deoxyuridylate in its conjugate acid and conjugate base forms, respectively, is a deoxynucleotide. It belongs to the class of organic compounds known as pyrimidine 2'-deoxyribonucleoside monophosphates. These are pyrimidine nucleotides with a monophosphate group linked to the ribose moiety lacking a hydroxyl group at position 2. dUMP exists in all living species, ranging from bacteria to humans. Within humans, dUMP participates in a number of enzymatic reactions. In particular, dUMP can be biosynthesized from dCMP through its interaction with the enzyme deoxycytidylate deaminase. In addition, dUMP can be biosynthesized from deoxyuridine; which is mediated by the enzyme thymidine kinase, cytosolic. In humans, dUMP is involved in pyrimidine metabolism. A pyrimidine 2'-deoxyribonucleoside 5'-monophosphate having uracil as the nucleobase. Outside of the human body, dUMP has been detected, but not quantified in several different foods, such as breadnut tree seeds, sea-buckthornberries, sour cherries, black walnuts, and common oregano.
Diazoxide is only found in individuals that have used or taken this drug. It is a benzothiadiazine derivative that is a peripheral vasodilator used for hypertensive emergencies. It lacks diuretic effect, apparently because it lacks a sulfonamide group. [PubChem]As a diuretic, diazoxide inhibits active chloride reabsorption at the early distal tubule via the Na-Cl cotransporter, resulting in an increase in the excretion of sodium, chloride, and water. Thiazides like diazoxide also inhibit sodium ion transport across the renal tubular epithelium through binding to the thiazide sensitive sodium-chloride transporter. This results in an increase in potassium excretion via the sodium-potassium exchange mechanism. The antihypertensive mechanism of diazoxide is less well understood although it may be mediated through its action on carbonic anhydrases in the smooth muscle or through its action on the large-conductance calcium-activated potassium (KCa) channel, also found in the smooth muscle. As a antihypoglycemic, diazoxide inhibits insulin release from the pancreas, probably by opening potassium channels in the beta cell membrane.
Diclofenac is only found in individuals that have used or taken this drug. It is a non-steroidal anti-inflammatory agent (NSAID) with antipyretic and analgesic actions. It is primarily available as the sodium salt. [PubChem]The antiinflammatory effects of diclofenac are believed to be due to inhibition of both leukocyte migration and the enzyme cylooxygenase (COX-1 and COX-2), leading to the peripheral inhibition of prostaglandin synthesis. As prostaglandins sensitize pain receptors, inhibition of their synthesis is responsible for the analgesic effects of diclofenac. Antipyretic effects may be due to action on the hypothalamus, resulting in peripheral dilation, increased cutaneous blood flow, and subsequent heat dissipation.
Dihydrocapsaicin is found in pepper (C. annuum). It is a potential nutriceutical. Dihydrocapsaicin is a capsaicinoid and analog and congener of capsaicin in chili peppers (Capsicum). Like capsaicin it is an irritant. Dihydrocapsaicin accounts for about 22% of the total capsaicinoids mixture and has about the same pungency as capsaicin. Pure dihydrocapsaicin is a lipophilic colorless odorless crystalline to waxy compound. It is soluble in dimethyl sulfoxide and 100 % ethanol.
3,4-Dihydro-2H-1-benzopyran-2-one, also known as 3,4-dihydrocoumarin or 1,2-benzodihydropyrone, belongs to the class of organic compounds known as 3,4-dihydrocoumarins. These are 3,4-dihydrogenated coumarins. Coumarin is a bicyclic compound that are 1-benzopyran carrying an oxo group at the 2-position. 3,4-Dihydro-2H-1-benzopyran-2-one exists in all living organisms, ranging from bacteria to humans. 3,4-Dihydro-2H-1-benzopyran-2-one is a sweet, almond, and cinnamon tasting compound. 3,4-Dihydro-2H-1-benzopyran-2-one has been detected, but not quantified, in several different foods, such as green vegetables, pulses, sour cherries, and tarragons. A chromanone that is the 3,4-dihydro derivative of coumarin.
L-Dihydroorotic acid, also known as (S)-4,5-dihydroorotate or dihydro-L-orotate, belongs to the class of organic compounds known as alpha amino acids and derivatives. These are amino acids in which the amino group is attached to the carbon atom immediately adjacent to the carboxylate group (alpha carbon), or a derivative thereof. 4,5-Dihydroorotic acid is a derivative of orotic acid which serves as an intermediate in pyrimidine biosynthesis. L-Dihydroorotic acid is a drug. L-Dihydroorotic acid exists in all living species, ranging from bacteria to humans. Within humans, L-dihydroorotic acid participates in a number of enzymatic reactions. In particular, L-dihydroorotic acid can be biosynthesized from ureidosuccinic acid; which is catalyzed by the enzyme cad protein. In addition, L-dihydroorotic acid and quinone can be converted into orotic acid through the action of the enzyme dihydroorotate dehydrogenase (quinone), mitochondrial. In humans, L-dihydroorotic acid is involved in the metabolic disorder called the beta-ureidopropionase deficiency pathway. Outside of the human body, L-dihydroorotic acid has been detected, but not quantified in several different foods, such as black chokeberries, vanilla, sweet basils, soy beans, and broad beans.
Dihydroxyacetone phosphate is an important intermediate in lipid biosynthesis and in glycolysis. Dihydroxyacetone phosphate is found to be associated with transaldolase deficiency, which is an inborn error of metabolism. Dihydroxyacetone phosphate has been identified in the human placenta (PMID: 32033212).
Docosahexaenoic acid (DHA) is an omega-3 essential fatty acid. Chemically, DHA is a carboxylic acid with a 22-carbon chain and six cis- double bonds with the first double bond located at the third carbon from the omega end. DHA is most often found in fish oil. It is a major fatty acid in sperm and brain phospholipids, especially in the retina. Dietary DHA can reduce the level of blood triglycerides in humans, which may reduce the risk of heart disease (Wikipedia). Docosahexaenoic acid is found to be associated with isovaleric acidemia, which is an inborn error of metabolism.
Adrenic acid, also known as 7,10,13,16-docosatetraenoic acid or adrenate, is a member of the class of compounds known as very long-chain fatty acids. Very long-chain fatty acids are fatty acids with an aliphatic tail that contains at least 22 carbon atoms. Adrenic acid is practically insoluble (in water) and a weakly acidic compound (based on its pKa). Adrenic acid can be found in blood and in human myelin tissue. Within the cell, adrenic acid is primarily located in the cytoplasm, in the membrane (predicted from logP), and in the peroxisome. It can also be found in the extracellular space. In humans, adrenic acid is involved in alpha-linolenic acid and linoleic acid metabolism. Docosatetraenoic acid designates any straight chain 22:4 fatty acid. In particular, all-cis-7,10,13,16-docosatetraenoic acid is an ω-6 fatty acid with the trivial name adrenic acid (AdA). This is a naturally occurring polyunsaturated fatty acid formed through a 2-carbon chain elongation of arachidonic acid. It is one of the most abundant fatty acids in the early human brain. This unsaturated fatty acid is also metabolized by cells into biologically active products, such as dihomoprostaglandins and dihomo-epoxyeicosatrienoic acids (dihomo-EETs) (Wikipedia). Adrenic acid, which is a prostacyclin inhibitor, appears to be a potential prothrombotic agent (PMID: 1642692).
Dofetilide is a class III antiarrhythmic agent that is approved by the Food and Drug Administration (FDA) for the maintenance of sinus rhythm in individuals prone to the formation of atrial fibrillation and flutter, and for the chemical cardioversion to sinus rhythm from atrial fibrillation and flutter. [Wikipedia]
Doxorubicin is only found in individuals that have used or taken this drug. It is antineoplastic antibiotic obtained from Streptomyces peucetius. It is a hydroxy derivative of daunorubicin. [PubChem]Doxorubicin has antimitotic and cytotoxic activity through a number of proposed mechanisms of action: Doxorubicin forms complexes with DNA by intercalation between base pairs, and it inhibits topoisomerase II activity by stabilizing the DNA-topoisomerase II complex, preventing the religation portion of the ligation-religation reaction that topoisomerase II catalyzes.
Efavirenz (brand names Sustiva and Stocrin) is a non-nucleoside reverse transcriptase inhibitor (NNRTI) and is used as part of highly active antiretroviral therapy (HAART) for the treatment of a human immunodeficiency virus (HIV) type 1.
Enalaprilat belongs to the family of Peptides. These are compounds containing an amide derived from two or more amino carboxylic acid molecules (the same or different) by formation of a covalent bond from the carbonyl carbon of one to the nitrogen atom of another. Enalaprilat is the active drug form of the ACE inhibitor Enalapril.
(-)-Catechin 3-O-gallate is a polyphenol compound found in foods of plant origin  (PMID: 20428313)
Epicatechin is an antioxidant flavonoid, occurring especially in woody plants as both (+)-catechin and (-)-epicatechin (cis) forms. Catechin is a tannin peculiar to green and white tea because the black tea oxidation process reduces catechins in black tea. Catechin is a powerful, water soluble polyphenol and antioxidant that is easily oxidized. Several thousand types are available in the plant world. As many as two thousand are known to have a flavon structure and are called flavonoids. Catechin is one of them. Green tea is manufactured from fresh, unfermented tea leaves; the oxidation of catechins is minimal, and hence they are able to serve as antioxidants. Researchers believe that catechin is effective because it easily sticks to proteins, blocking bacteria from adhering to cell walls and disrupting their ability to destroy them. Viruses have hooks on their surfaces and can attach to cell walls. The catechin in green tea prevents viruses from adhering and causing harm. Catechin reacts with toxins created by harmful bacteria (many of which belong to the protein family) and harmful metals such as lead, mercury, chrome, and cadmium. From its NMR espectra, there is a doubt on 2 and 3 atoms configuration. It seems to be that they are in trans position.
(-)-Epigallocatechin is found in almond. (-)-Epigallocatechin is widespread in plants; broad beans are an especially good source; present in green and black tea. Potential nutriceutica
Epirubicin is only found in individuals that have used or taken this drug. It is an anthracycline which is the 4&#39;-epi-isomer of doxorubicin. The compound exerts its antitumor effects by interference with the synthesis and function of DNA. [PubChem]Epirubicin has antimitotic and cytotoxic activity. It inhibits nucleic acid (DNA and RNA) and protein synthesis through a number of proposed mechanisms of action: Epirubicin forms complexes with DNA by intercalation between base pairs, and it inhibits topoisomerase II activity by stabilizing the DNA-topoisomerase II complex, preventing the religation portion of the ligation-religation reaction that topoisomerase II catalyzes. It also interferes with DNA replication and transcription by inhibiting DNA helicase activity.
Ergothioneine is a naturally occurring metabolite of histidine that has antioxidant properties. -- Pubchem. Ergothioneine is a product of plant origin that accumulates in animal tissues. Ergothioneine is biosynthesized exclusively by fungi and mycobacteria and is captured by plants through their roots. As an ingredient of human food, ET is distributed very unevenly. By far, the highest levels of Ergothioneine have been found in mushrooms (0.1-1 mg/g dried material). Ergothioneine is rapidly cleared from the circulation and then avidly retained with minimal metabolism: the whole-body half-life of ingested Ergothioneine in rats is 1 month. The content of Ergothioneine varies greatly among tissues and is strongly dependent on its dietary level. In addition to erythrocytes and bone marrow, high Ergothioneine levels have also been found in seminal fluid. The precise physiological role of ET has remained elusive since its discovery in 1909. It is known that Ergothioneine is a powerful scavenger of hydroxyl radicals and an inhibitor of iron or copper ion-dependent generation of hydroxyl radicals from hydrogen peroxide (H2O2). A specific ergothioneine transporter has recently been identified (gene symbol SLC22A4 - PMID: 15795384). Ergothioneine appears to play a pivotal protective role in monocytes, because the occurrence of rheumatoid arthritis and Crohn's disease has very recently been linked to variant ergothioneine transporter genes (PMID: 15795384). SLC22A4 is highly expressed in the kidney, where it is thought to aid in active secretion of organic cations, and may facilitate the active reabsorption of ergothioneine.
Erythrono-1,4-lactone has been identified as a lactone of tetronic acid in the urine from normal adults and neonates. The formation of this compound may be a consequence of lactonization of erythronic acid during the extraction/isolation process. Lactonization is a potential problem when measuring acids that contain a hydroxyl group at the number 4 carbon, as lactones are formed under acidic conditions. Evidence indicates that most 4-hydroxy acids do not normally exist to any appreciable extent as lactones in urine. (PMID 1192581).
Esomeprazole (brand names Nexium; Lucen; Esopral and Axagon in Italy) is a proton pump inhibitor which reduces gastric acid secretion through the inhibition of H+/K+-ATPase in gastric parietal cells. By inhibiting the functioning of this enzyme, the drug prevents the formation of gastric acid. Esomeprazole is used in the treatment of dyspepsia, peptic ulcer disease (PUD), gastroesophageal reflux disease (GORD/GERD), and Zollinger-Ellison syndrome. Esomeprazole is the S-enantiomer of omeprazole (marketed as Losec/Prilosec), and AstraZeneca claims improved efficacy of this single enantiomer product over the racemic mixture of omeprazole.
Estrone is a major mammalian estrogen. The conversion of the natural C19 steroids, testosterone and androstenedione into estrone is dependent on a complex key reaction catalyzed by the cytochrome P450 aromatase (EC 1.14.14.1, unspecific monooxygenase), which is expressed in many tissues of the adult human (e.g. ovary, fat tissue), but not in the liver. The ovaries after menopause continue to produce androstenedione and testosterone in significant amounts and these androgens are converted in fat, muscle, and skin into estrone. When women between the ages of 45 and 64 years have prophylactic oophorectomy (when hysterectomy is performed for benign disease to prevent the development of ovarian cancer), evidence suggests that oophorectomy increases the subsequent risk of coronary heart disease (CHD) and osteoporosis. Whereas 14,000 women die of ovarian cancer every year nearly 490,000 women die of heart disease and 48,000 women die within 1 year after hip fracture. Therefore, the decision to perform prophylactic oophorectomy should be approached with great caution for the majority of women who are at low risk of developing ovarian cancer. Steroid sulfatase (EC 3.1.6.2, STS) hydrolyzes steroid sulfates, such as estrone sulfate to estrone which can be converted to steroids with potent estrogenic properties, that is, estradiol; STS activity is much higher in breast tumors and high levels of STS mRNA expression in tumors are associated with a poor prognosis. The biological roles of estrogens in tumorigenesis are certainly different between the endometrium and breast, although both are considered "estrogen-dependent tissues". 17beta-hydroxysteroid dehydrogenases (EC 1.1.1.62, 17-HSDs) are enzymes involved in the formation of active sex steroids. estrone is interconverted by two enzymes 17-HSD types. Type 1 converts estrone to estradiol and Type 2 catalyzes the reverse reaction. (PMID: 17653961, 17513923, 17470679, 17464097).
Ethyl glucuronide is a natural human metabolite of Ethanol generated in the liver by UDP glucuonyltransferase. Glucuronidation is used to assist in the excretion of toxic substances, drugs or other substances that cannot be used as an energy source. Glucuronic acid is attached via a glycosidic bond to the substance, and the resulting glucuronide, which has a much higher water solubility than the original substance, is eventually excreted by the kidneys. Ethyl glucuronide is a general biomarker for the consumption of alcohol
Ethyl butyrate, also known as ethyl butanoate, or butyric ether, is an ester with the chemical formula CH3CH2CH2COOCH2CH3, with one oxygen having a double bond. It is soluble in propylene glycol, paraffin oil and kerosene. Ethyl butyrate is present in many fruits e.g. apple, apricot, banana, plum, tangerine etc. Ethyl butyrate is a flavouring ingredient and it can be synthesized by reacting ethanol and butyric acid. This is a condensation reaction, meaning water is produced in the reaction as a byproduct.
Etoposide, also known as vepesid or VP-16, belongs to the class of organic compounds known as podophyllotoxins. These are tetralin lignans in which the benzene moiety of the tetralin skeleton is fused to a 1,3-dioxolane and the cyclohexane is fused to a butyrolactone (pyrrolidin-2-one). Etoposide is a drug. Within humans, etoposide participates in a number of enzymatic reactions. In particular, etoposide can be converted into etoposide ortho-quinone; which is mediated by the enzymes prostaglandin g/h synthase 1 and prostaglandin g/h synthase 2. In addition, etoposide and uridine diphosphate glucuronic acid can be converted into etoposide glucuronide and uridine 5'-diphosphate; which is mediated by the enzyme UDP-glucuronosyltransferase 1-1. In humans, etoposide is involved in etoposide metabolism pathway. Etoposide is formally rated as a carcinogen (by IARC 1) and is also a potentially toxic compound. Etoposide is used as a form of chemotherapy for cancers such as Kaposi's sarcoma, Ewing's sarcoma, lung cancer, testicular cancer, lymphoma, nonlymphocytic leukemia, and glioblastoma multiforme. It is given intravenously (IV) or orally in capsule or tablet form. It is believed to work by damaging DNA. Etoposide was approved for medical use in the United States in 1983. They can include low blood cell counts, vomiting, loss of appetite, diarrhea, hair loss, and fever.
Ezetimibe is an anti-hyperlipidemic medication which is used to lower cholesterol levels. Specifically, it appears to bind to a critical mediator of cholesterol absorption, the Niemann-Pick C1-Like 1 (NPC1L1) protein on the gastrointestinal tract epithelial cells as well as in hepatocytes.
Famotidine is a histamine H2-receptor antagonist that inhibits stomach acid production, and is commonly used in the treatment of peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD/GORD). It is commonly marketed by Merck under the trade names Pepcidine and Pepcid.
Fenoldopam is only found in individuals that have used or taken this drug. It is a dopamine D1 receptor agonist that is used as an antihypertensive agent. It lowers blood pressure through arteriolar vasodilation. [PubChem]Fenoldopam is a rapid-acting vasodilator. It is an agonist for D<sub>1</sub>-like dopamine receptors and binds with moderate affinity to &alpha;<sub>2</sub>-adrenoceptors. It has no significant affinity for D<sub>2</sub>-like receptors, &alpha;<sub>1</sub> and &beta;-adrenoceptors, 5<sub>HT1</sub> and 5<sub>HT2</sub> receptors, or muscarinic receptors. Fenoldopam is a racemic mixture with the R-isomer responsible for the biological activity. The R-isomer has approximately 250-fold higher affinity for D<sub>1</sub>-like receptors than does the S-isomer. In non-clinical studies, fenoldopam had no agonist effect on presynaptic D<sub>2</sub>-like dopamine receptors, or &alpha; or &beta; -adrenoceptors, nor did it affect angiotensin-converting enzyme activity. Fenoldopam may increase norepinephrine plasma concentration.
trans-Ferulic acid is a highly abundant phenolic phytochemical which is present in plant cell walls. Ferulic acid is a phenolic acid that can be absorbed by the small intestine and excreted through the urine. It is one of the most abundant phenolic acids in plants, varying from 5 g/kg in wheat bran to 9 g/kg in sugar-beet pulp and 50 g/kg in corn kernel. It occurs primarily in seeds and leaves both in its free form (albeit rarely) and covalently linked to lignin and other biopolymers. It is usually found as ester cross-links with polysaccharides in the cell wall, such as arabinoxylans in grasses, pectin in spinach and sugar beet, and xyloglucans in bamboo. It also can cross-link with proteins. Due to its phenolic nucleus and an extended side chain conjugation (carbohydrates and proteins), it readily forms a resonance-stabilized phenoxy radical which accounts for its potent antioxidant potential. Food supplementation with curcumin and ferulic acid is considered a nutritional approach to reducing oxidative damage and amyloid pathology in Alzheimer disease (PMID:17127365, 1398220, 15453708, 9878519). Ferulic acid can be found in Pseudomonas and Saccharomyces (PMID:8395165).
Flavin adenine dinucleotide (FAD) is a redox-active coenzyme associated with various proteins, which is involved with several enzymatic reactions in metabolism. FAD, also known as adeflavin or flamitajin b, belongs to the class of organic compounds known as flavin nucleotides. These are nucleotides containing a flavin moiety. Flavin is a compound that contains the tricyclic isoalloxazine ring system, which bears 2 oxo groups at the 2- and 4-positions. FAD is a drug which is used to treat eye diseases caused by vitamin b2 deficiency, such as keratitis and blepharitis. FAD exists in all living species, ranging from bacteria to humans. In humans, FAD is involved in the metabolic disorder called the medium chain acyl-coa dehydrogenase deficiency (mcad) pathway. Outside of the human body, FAD has been detected, but not quantified in several different foods, such as other bread, passion fruits, asparagus, kelps, and green bell peppers. It is a flavoprotein in which the substituent at position 10 of the flavin nucleus is a 5'-adenosyldiphosphoribityl group.
Flurbiprofen, a propionic acid derivative, is a nonsteroidal anti-inflammatory agent (NSAIA) with antipyretic and analgesic activity. Oral formulations of flurbiprofen may be used for the symptomatic treatment of rheumatoid arthritis, osteoarthritis and anklylosing spondylitis. Flurbiprofen may also be used topically prior to ocular surgery to prevent or reduce intraoperative miosis. Flurbiprofen is structurally and pharmacologically related to fenoprofen, ibuprofen, and ketoprofen.
Formononetin are abundant in vegetables. It is a phyto-oestrogen that is a polyphenolic non-steroidal plant compound with oestrogen-like biological activity (PMID: 16108819). It can be the source of considerable estrogenic activity (http://www.herbalchem.net/Intermediate.htm).
Formoterol is a long-acting (12 hours) beta2-agonist used in the management of asthma and/or chronic obstructive pulmonary disease (COPD). Inhaled formoterol works like other beta2-agonists, causing bronchodilatation through relaxation of the smooth muscle in the airway so as to treat the exacerbation of asthma.
This compound belongs to the family of Monosaccharide Phosphates. These are monosaccharides comprising a phosphated group linked tot he carbohydrate unit.
Fumaric acid is a dicarboxylic acid. It is a precursor to L-malate in the Krebs tricarboxylic acid (TCA) cycle. It is formed by the oxidation of succinic acid by succinate dehydrogenase. Fumarate is converted by the enzyme fumarase to malate. Fumaric acid has recently been identified as an oncometabolite or an endogenous, cancer causing metabolite. High levels of this organic acid can be found in tumors or biofluids surrounding tumors. Its oncogenic action appears to due to its ability to inhibit prolyl hydroxylase-containing enzymes. In many tumours, oxygen availability becomes limited (hypoxia) very quickly due to rapid cell proliferation and limited blood vessel growth. The major regulator of the response to hypoxia is the HIF transcription factor (HIF-alpha). Under normal oxygen levels, protein levels of HIF-alpha are very low due to constant degradation, mediated by a series of post-translational modification events catalyzed by the prolyl hydroxylase domain-containing enzymes PHD1, 2 and 3, (also known as EglN2, 1 and 3) that hydroxylate HIF-alpha and lead to its degradation. All three of the PHD enzymes are inhibited by fumarate. Fumaric acid is found to be associated with fumarase deficiency, which is an inborn error of metabolism. It is also a metabolite of Aspergillus.
Galactose is an optical isomer of glucose. An aldohexose that occurs naturally in the D-form in lactose, cerebrosides, gangliosides, and mucoproteins. Deficiency of galactosyl-1-phosphate uridyltransferase (Galactose-1-phosphate uridyl-transferase deficiency disease) causes an error in galactose metabolism called galactosemia, resulting in elevations of galactose in the blood. Galactose (Gal) (also called brain sugar) is a type of sugar found in dairy products, in sugar beets and other gums and mucilages. It is also synthesized by the body, where it forms part of glycolipids and glycoproteins in several tissues. It is considered a nutritive sweetener because it has food energy. Galactose is less sweet than glucose and not very water-soluble. Galactose is a monosaccharide constituent, together with glucose, of the disaccharide lactose. The hydrolysis of lactose to glucose and galactose is catalyzed by the enzyme beta-galactosidase, a lactase. In the human body, glucose is changed into galactose in order to enable the mammary glands to secrete lactose. Galactan is a polymer of the sugar galactose. It is found in hemicellulose and can be converted to galactose by hydrolysis.
Gallic acid is an organic acid, also known as 3,4,5-trihydroxybenzoic acid, found in gallnuts, sumac, witch hazel, tea leaves, oak bark, and other plants. The chemical formula is C6H2(OH)3CO2H. Gallic acid is widely distributed in plants and is found both free and as part of tannins. It is commonly used in the pharmaceutical industry. Gallic acid can also be used to synthesize the hallucinogenic alkaloid mescaline, also known as 3,4,5-trimethoxyphenethylamine. Salts and esters of gallic acid are termed gallates. Gallic acid has been found to be s metabolite of Aspergillus (PMID:24031294).
N2-gamma-Glutamylglutamine, also known as gamma-L-Glu-L-Gln or L-gamma-glutamyl-L-glutamine, belongs to the class of organic compounds known as dipeptides. These are organic compounds containing a sequence of exactly two alpha-amino acids joined by a peptide bond. N2-gamma-Glutamylglutamine is a very strong basic compound (based on its pKa). N2-gamma-Glutamylglutamine is a dipeptide obtained from the condensation of the gamma-carboxy group of glutamic acid with the alpha-amino group of glutamine. Some dipeptides are known to have physiological or cell-signalling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis.
gamma-Glutamylleucine is a dipeptide composed of gamma-glutamate and leucine, and is a proteolytic breakdown product of larger proteins. It belongs to the family of N-acyl-alpha amino acids and derivatives. These are compounds containing an alpha amino acid which bears an acyl group at its terminal nitrogen atom. gamma-Glutamylleucine is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis. gamma-Glutamylleucine is a biomarker for the consumption of whey protein. It is found in urine (PMID: 3782411).
gamma-Glutamylmethionine is a dipeptide composed of gamma-glutamate and methionine, and is a proteolytic breakdown product of larger proteins. It belongs to the family of N-acyl-alpha amino acids and derivatives. These are compounds containing an alpha amino acid which bears an acyl group at its terminal nitrogen atom. gamma-Glutamylmethionine is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis. gamma-Glutamylmethionine is found in onion-family vegetables. It is isolated from the seeds of onion (Allium cepa), kidney bean (Phaseolus vulgaris), mung bean (Vigna radiata), garlic (Allium sativum), and black gram (Vigna mungo).
gamma-Glutamyltyrosine is a dipeptide composed of gamma-glutamate and tyrosine, and is a proteolytic breakdown product of larger proteins. It belongs to the family of N-acyl-alpha amino acids and derivatives. These are compounds containing an alpha amino acid which bears an acyl group at its terminal nitrogen atom. gamma-Glutamyltyrosine is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis.
Gentisic acid, also known as gentisate or 2,5-dioxybenzoate, belongs to the class of organic compounds known as hydroxybenzoic acid derivatives. Hydroxybenzoic acid derivatives are compounds containing a hydroxybenzoic acid (or a derivative), which is a benzene ring bearing a carboxyl and a hydroxyl groups. Gentisic acid is also classified as a dihydroxybenzoic acid.  It is a derivative of benzoic acid and a minor (1%) product of the metabolic break down of aspirin, which is excreted by the kidneys. Gentisic acid is found in essentially all organisms ranging from bacteria to fungi to plants to animals. Gentisic acid has been associated with a number of useful effects on human health and exhibits anti-inflammatory, antigenotoxic, hepatoprotective, neuroprotective, antimicrobial, and especially antioxidant activities (PMID: 31825145). It is widely distributed in plants as a secondary plant product such as Gentiana spp., Citrus spp., Vitis vinifera, Pterocarpus santalinus, Helianthus tuberosus, Hibiscus rosa-sinensis, Olea europaea, and Sesamum indicum and in fruits such as avocados, batoko plum, kiwi fruits, apple, bitter melon, black berries, pears, and some mushrooms (PMID: 31825145). Gentisic acid is found in higher concentrations in a number of foods such as tarragons, common thymes, and common sages and in a lower concentration in grape wines, rosemaries, and sweet marjorams. Gentisic acid has also been shown to act as a pathogen-inducible signal for the activation of plant defenses in tomato plants and cucumbers (PMID: 16321412; https://doi.org/10.1094/MPMI.1999.12.3.227).
Gibberellic acid, also known as gibberellin A3, GA, or GA3, is a very potent hormone whose natural occurrence in plants controls their development. Since GA regulates growth, applications of very low concentrations can have a profound effect while too much will have the opposite effect. Gibberellic acid is a hormone found in plants. Gibberellic acid is a simple gibberellin promoting the growth and elongation of cells. It affects the decomposition of plants. It also helps plants grow if used in small amounts but eventually, plants grow a tolerance for it. Gibberellic acid stimulates the cells of germinating seeds to produce mRNA molecules that code for hydrolytic enzymes.
Glimepiride is only found in individuals that have used or taken this drug. It is the first III generation sulphonyl urea it is a very potent sulphonyl urea with long duration of action.The mechanism of action of glimepiride in lowering blood glucose appears to be dependent on stimulating the release of insulin from functioning pancreatic beta cells, and increasing sensitivity of peripheral tissues to insulin. Glimepiride likely binds to ATP-sensitive potassium channel receptors on the pancreatic cell surface, reducing potassium conductance and causing depolarization of the membrane. Membrane depolarization stimulates calcium ion influx through voltage-sensitive calcium channels. This increase in intracellular calcium ion concentration induces the secretion of insulin.
Glutamylthreonine is a dipeptide composed of glutamate and threonine, and is a proteolytic breakdown product of larger proteins. It belongs to the family of N-acyl-alpha amino acids and derivatives. These are compounds containing an alpha amino acid which bears an acyl group at its terminal nitrogen atom. Glutamylthreonine is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis.
Glucoraphanin belongs to the class of organic compounds known as alkylglucosinolates. These are organic compounds containing a glucosinolate moiety that carries an alkyl chain. Outside of the human body, glucoraphanin has been detected, but not quantified in, several different foods, such as radish, common cabbages, Brassicas, Chinese cabbages, and cabbages. This could make glucoraphanin a potential biomarker for the consumption of these foods.
Glucosamine 6-phosphate (CAS: 3616-42-0) is normally produced in endothelial cells via de novo glucosamine synthesis by the enzyme fructose-6-phosphate amidotransferase and the modulation of this pathway by hyperglycemia and glutamine. Glutamine-fructose-6-phosphate amidotransferase (GFAT) catalyzes the first committed step in the pathway for biosynthesis of hexosamines in mammals.It is a member of the N-terminal nucleophile class of amidotransferases, GFAT transfers the amino group from the L-glutamine amide to D-fructose 6-phosphate, producing glutamic acid and glucosamine 6-phosphate. As glucosamine inhibits endothelial nitric oxide synthesis it has important implications for impaired endothelium-dependent relaxation and vascular dysfunction in diabetes mellitus (PMID:11270676, 11842094).
Glucose 1-phosphate (also called cori ester) is a glucose molecule with a phosphate group on the 1'-carbon. It can exist in either the α- or β-anomeric form. Glucose 1-phosphate belongs to the class of organic compounds known as monosaccharide phosphates. These are monosaccharides comprising a phosphated group linked to the carbohydrate unit. Glucose 1-phosphate is the direct product of the reaction in which glycogen phosphorylase cleaves off a molecule of glucose from a greater glycogen structure. It cannot travel down many metabolic pathways and must be interconverted by the enzyme phosphoglucomutase in order to become glucose 6-phosphate. Free glucose 1-phosphate can also react with UTP to form UDP-glucose. It can then return to the greater glycogen structure via glycogen synthase.
Oxidized glutathione, also known as glutathione disulfide or GSSG, belongs to the class of organic compounds known as peptides. Peptides are compounds containing an amide derived from two or more amino carboxylic acid molecules (the same or different) by the formation of a covalent bond from the carbonyl carbon of one to the nitrogen atom of another. In humans, oxidized glutathione is involved in the metabolic disorder called leukotriene C4 synthesis deficiency pathway. Outside of the human body, oxidized glutathione has been detected, but not quantified in several different foods, such as leeks, star anises, mamey sapotes, climbing beans, and common persimmons. Oxidized glutathione is a glutathione dimer formed by a disulfide bond between the cysteine sulfhydryl side chains during the course of being oxidized. Glutathione participates in leukotriene synthesis and is a cofactor for the enzyme glutathione peroxidase. It is also important as a hydrophilic molecule that is added to lipophilic toxins and waste in the liver during biotransformation before they can become part of the bile. Glutathione is also needed for the detoxification of methylglyoxal, a toxin produced as a by-product of metabolism. This detoxification reaction is carried out by the glyoxalase system. Glyoxalase I (EC 4.4.1.5) catalyzes the conversion of methylglyoxal and reduced glutathione into S-D-lactoyl-glutathione. Glyoxalase II (EC 3.1.2.6) catalyzes the hydrolysis of S-D-lactoyl-glutathione into glutathione and D-lactate.
Glycylglycylglycine, also known as GGG or triglycine, belongs to the class of organic compounds known as oligopeptides. These are organic compounds containing a sequence of between three and ten alpha-amino acids joined by peptide bonds. A tripeptide in which three glycine units are linked via peptide bonds in a linear sequence. Glycylglycylglycine has been detected, but not quantified, in fruits. This could make glycylglycylglycine a potential biomarker for the consumption of these foods. Glycylglycylglycine is a potentially toxic compound.
Glycyl-Isoleucine is a dipeptide composed of glycine and isoleucine. It is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis. This dipeptide has not yet been identified in human tissues or biofluids and so it is classified as an 'Expected' metabolite.
Glycyltyrosine is a dipeptide composed of glycine and tyrosine. It is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis.
Glyceraldehyde is a triose monosaccharide with chemical formula C3H6O3. It is the simplest of all common aldoses. It is a sweet, colourless crystalline solid that is an intermediate compound in carbohydrate metabolism. The word "glyceraldehyde" comes from combining glycerine and aldehyde, as glyceraldehyde is merely glycerine with one hydroxide changed to an aldehyde. Glyceraldehyde is produced from the action of the enzyme glyceraldehyde dehydrogenase, which converts glycerol to glyceraldehyde using NADP as a cofactor. When present at sufficiently high levels, glyceraldehyde can be a cytotoxin and a mutagen. A cytotoxin is a compound that kills cells. A mutagen is a compound that causes mutations in DNA. Glyceraldehyde is a highly reactive compound that can modify and cross-link proteins. Glyceraldehyde-modified proteins appear to be cytotoxic, depress intracellular glutathione levels, and induce reactive oxygen species (ROS) production (PMID:14981296). Glyceraldehyde has been shown to cause chromosome damage to human cells in culture and is mutagenic in the Ames bacterial test.
Glyceric acid is a colourless syrupy acid, obtained from oxidation of glycerol. It is a compound that is secreted excessively in the urine by patients suffering from D-glyceric aciduria, an inborn error of metabolism, and D-glycerate anemia. Deficiency of human glycerate kinase leads to D-glycerate acidemia/D-glyceric aciduria. Symptoms of the disease include progressive neurological impairment, hypotonia, seizures, failure to thrive, and metabolic acidosis. At sufficiently high levels, glyceric acid can act as an acidogen and a metabotoxin. An acidogen is an acidic compound that induces acidosis, which has multiple adverse effects on many organ systems. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Glyceric acid is an organic acid. Abnormally high levels of organic acids in the blood (organic acidemia), urine (organic aciduria), the brain, and other tissues lead to general metabolic acidosis. Acidosis typically occurs when arterial pH falls below 7.35. In infants with acidosis, the initial symptoms include poor feeding, vomiting, loss of appetite, weak muscle tone (hypotonia), and lack of energy (lethargy). These can progress to heart abnormalities, seizures, coma, and possibly death. These are also the characteristic symptoms of untreated glyceric aciduria. Many affected children with organic acidemias experience intellectual disability or delayed development. In adults, acidosis or acidemia is characterized by headaches, confusion, feeling tired, tremors, sleepiness, and seizures. Elevated values may also be due to microbial sources such as yeast (Aspergillus, Penicillium, probably Candida) or due to dietary sources containing glycerol (glycerine). Glyceric acid is isolated from various plants (e.g. brassicas, pulses, and Vicia faba).
Glycerol or glycerin is a colourless, odourless, viscous liquid that is sweet-tasting and mostly non-toxic. It is widely used in the food industry as a sweetener and humectant and in pharmaceutical formulations. Glycerol is an important component of triglycerides (i.e. fats and oils) and of phospholipids. Glycerol is a three-carbon substance that forms the backbone of fatty acids in fats. When the body uses stored fat as a source of energy, glycerol and fatty acids are released into the bloodstream. The glycerol component can be converted into glucose by the liver and provides energy for cellular metabolism. Normally, glycerol shows very little acute toxicity and very high oral doses or acute exposures can be tolerated. On the other hand, chronically high levels of glycerol in the blood are associated with glycerol kinase deficiency (GKD). GKD causes the condition known as hyperglycerolemia, an accumulation of glycerol in the blood and urine. There are three clinically distinct forms of GKD: infantile, juvenile, and adult. The infantile form is the most severe and is associated with vomiting, lethargy, severe developmental delay, and adrenal insufficiency. The mechanisms of glycerol toxicity in infants are not known, but it appears to shift metabolism towards chronic acidosis. Acidosis typically occurs when arterial pH falls below 7.35. In infants with acidosis, the initial symptoms include poor feeding, vomiting, loss of appetite, weak muscle tone (hypotonia), and lack of energy (lethargy). These can progress to heart, liver, and kidney abnormalities, seizures, coma, and possibly death. These are also the characteristic symptoms of untreated GKD. Many affected children with organic acidemias experience intellectual disability or delayed development. Patients with the adult form of GKD generally have no symptoms and are often detected fortuitously.
Glycitein is a soy isoflavone. It is a minor component in most soy products. It's role of reducing low-density lipoprotein cholesterol is not clear. Glycitein is metabolized by human gut microorganisms and may follow metabolic pathways similar to other soy isoflavones (PMID: 12011578; 16248547). Glycitein is a biomarker for the consumption of soy beans and other soy products.
Glycylleucine is a dipeptide composed of glycine and leucine. It is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis. It appears to be a common substrate for glycyl-leucine dipeptidase.
Goserelin is a synthetic hormone. In men, it stops the production of the hormone testosterone, which may stimulate the growth of cancer cells. In women, goserelin decreases the production of the hormone estradiol (which may stimulate the growth of cancer cells) to levels similar to a postmenopausal state. When the medication is stopped, hormone levels return to normal.
Guanidoacetic acid (GAA), also known as guanidinoacetate or glycocyamine, belongs to the class of organic compounds known as alpha amino acids and derivatives. These are amino acids in which the amino group is attached to the carbon atom immediately adjacent to the carboxylate group (alpha carbon), or a derivative thereof. Guanidinoacetic acid was first prepared in 1861 by Adolph Strecker by reaction of cyanamide with glycine in aqueous solution. Manufactured guanidinoacetic acid is primarily used a feed additive approved by EFSA in poultry farming (for fattening), and pigs for fattening. Guanidoacetic acid exists naturally in all vertebrates. It is formed primarily in the kidneys by transferring the guanidine group of L-arginine to the amino acid glycine via the enzyme known as L-Arg:Gly-amidinotransferase (AGAT). In a further step, guanidinoacetate is methylated to generate creatine using S-adenosyl methionine (as the methyl donor) via the enzyme known as guanidinoacetate N-methyltransferase (GAMT). The resulting creatine is released into the bloodstream. Elevated levels of guanidoacetic acid are a characteristic of an inborn metabolic disorder known as Guanidinoacetate Methyltransferase (GAMT) Deficiency. GAMT converts guanidinoacetate to creatine and deficiency of this enzyme results in creatine depletion and accumulation of guanidinoacetate The disorder is transmitted in an autosomal recessive fashion and is localized to mutations on chromosome 19p13.3. GAMT deficiency is characterized by developmental arrest, medication-resistant epilepsy (myoclonic, generalized tonic-clonic, partial complex, atonic), severe speech impairment, progressive dystonia, dyskinesias, hypotonia, ataxia, and autistic-like behavior.
Guanosine cyclic 3',5'-(hydrogen phosphate). A guanine nucleotide containing one phosphate group which is esterified to the sugar moiety in both the 3'- and 5'-positions. It is a cellular regulatory agent and has been described as a second messenger. Its levels increase in response to a variety of hormones, including acetylcholine, insulin, and oxytocin and it has been found to activate specific protein kinases. (From Merck Index, 11th ed).
Guanosine monophosphate (GMP), also known as 5′-guanidylic acid or guanylic acid (conjugate base guanylate), is a nucleotide that is used as a monomer in RNA. It is an ester of phosphoric acid with the nucleoside guanosine. GMP consists of the phosphate group, the pentose sugar ribose, and the nucleobase guanine; hence it is a ribonucleoside monophosphate. Guanosine monophosphate is commercially produced by microbial fermentation. Guanosine monophosphate, also known as guanylic acid or 5'-GMP, belongs to the class of organic compounds known as purine ribonucleoside monophosphates. These are nucleotides consisting of a purine base linked to a ribose to which one monophosphate group is attached. A guanine nucleotide containing one phosphate group esterified to the sugar moiety and found widely in nature. Guanosine monophosphate exists in all living species, ranging from bacteria to humans. Within humans, guanosine monophosphate participates in a number of enzymatic reactions. In particular, guanosine triphosphate and guanosine monophosphate can be biosynthesized from diguanosine tetraphosphate through its interaction with the enzyme bis(5'-nucleosyl)-tetraphosphatase [asymmetrical]. In addition, guanosine monophosphate can be biosynthesized from guanosine diphosphate; which is mediated by the enzyme ectonucleoside triphosphate diphosphohydrolase 5. In humans, guanosine monophosphate is involved in the metabolic disorder called the lesch-nyhan syndrome (lns) pathway. Outside of the human body, guanosine monophosphate has been detected, but not quantified in several different foods, such as common cabbages, tea, winter squash, spearmints, and sugar apples.
Henicosanoic acid, also known as N-heneicosanoate or 21:0,is a long-chain fatty acid that is henicosane in which one of the methyl groups has been oxidised to give the corresponding carboxylic acid. It is a straight-chain saturated fatty acid and a long-chain fatty acid. It is a conjugate acid of a henicosanoate. Heneicosanoic acid belongs to the class of organic compounds known as long-chain fatty acids. These are fatty acids with an aliphatic tail that contains between 13 and 21 carbon atoms. Heneicosanoic acid is a very hydrophobic molecule, practically insoluble in water, and relatively neutral. Heneicosanoic acid is a potentially toxic compound.
Histamine is an amine derived by enzymatic decarboxylation of histidine. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter. Histamine can be found in Photobacterium phosphoreum and Lactobacillus (PMID:17066936). Histamine belongs to the class of organic compounds known as 2-arylethylamines. These are primary amines that have the general formula RCCNH2, where R is an organic group. High amounts of histamine have been found in spinach, oats and ryes. Another foods such as green beans, broccoli, and beetroots also contain histamine but in lower concentrations. Histamine has also been detected but not quantified in several different foods, such as groundcherries, carobs, bok choy, biscuits, and longans.
L-homoarginine, also known as N6-(aminoiminomethyl)-L-lysine or N6-amidino-L-lysine, is a member of the class of compounds known as L-alpha-amino acids. L-alpha-amino acids are alpha amino acids which have the L-configuration of the alpha-carbon atom. More specifically, L-homoarginine is a naturally occurring, non-proteinogenic, cationic amino acid. It is formed in the liver in a reaction catalyzed by L-arginine:glycine amidinotransferase (AGAT) when transferring the amidino group from arginine to lysine. It is an alternative substrate for nitric oxide (NO) synthase. L-homoarginine increases the availability of NO and thereby affects endothelial function. High homoarginine levels may exert positive actions that are relevant to cardiovascular health, including enhanced endothelial function, inhibition of platelet aggregation and stimulation of insulin secretion (PMID: 30866658). Recent studies have demonstrated that low serum homoarginine levels are a strong predictor of cardiovascular mortality (PMID: 24583919). L-homoarginine is a substrate of the human cationic amino acid CAT1 [solute carrier family 7 (SLC7A1)], CAT2A (SLC7A2A) or CAT2B (SLC7A2B) (PMID: 28684763). According to published human metabolomic data, L-homoarginine can be found primarily in blood, cerebrospinal fluid (CSF), and urine, as well as in human intestinal and testes tissues. Moreover, L-homoarginine has been found to be associated with liver cirrhosis and the genetic disorder, hyperargininemia. Homoarginine is an organ-specific uncompetitive inhibitor of human liver and bone alkaline phosphohydrolase (PMID: 5063678).
Homoserine is a more reactive variant of the amino acid serine. In this variant, the hydroxyl side chain contains an additional CH2 group which brings the hydroxyl group closer to its own carboxyl group, allowing it to chemically react to form a five-membered ring. This occurs at the point that amino acids normally join to their neighbours in a peptide bond. Homoserine is therefore unsuitable for forming proteins and has been eliminated from the repertoire of amino acids used by living things. Homoserine is the final product on the C-terminal end of the N-terminal fragment following a cyanogen bromide cleavage. (wikipedia). Homoserine is also a microbial metabolite.
Homovanillic acid (HVA), also known as homovanillate, belongs to the class of organic compounds known as methoxyphenols. Methoxyphenols are compounds containing a methoxy group attached to the benzene ring of a phenol moiety. HVA is also classified as a catechol.  HVA is a major catecholamine metabolite that is produced by a consecutive action of monoamine oxidase and catechol-O-methyltransferase on dopamine. HVA is typically elevated in patients with catecholamine-secreting tumors (such as neuroblastoma, pheochromocytoma, and other neural crest tumors). HVA levels are also used in monitoring patients who have been treated for these kinds tumors. HVA levels may also be altered in disorders of catecholamine metabolism such as monoamine oxidase-A (MOA) deficiency. MOA deficiency can cause decreased urinary HVA values, while a deficiency of dopamine beta-hydrolase (the enzyme that converts dopamine to norepinephrine) can cause elevated urinary HVA values. Within humans, HVA participates in a number of enzymatic reactions. In particular, HVA and pyrocatechol can be biosynthesized from 3,4-dihydroxybenzeneacetic acid and guaiacol. This reaction is catalyzed by the enzyme known as catechol O-methyltransferase. In addition, HVA can be biosynthesized from homovanillin through the action of the enzyme known aldehyde dehydrogenase. HVA has recently been found in a number of beers and appears to arise from the fermentation process (https://doi.org/10.1006/fstl.1999.0593). HVA is also a metabolite of Bifidobacterium (PMID: 24958563) and the bacterial breakdown of dietary flavonoids. Dietary flavonols commonly found in tomatoes, onions, and tea, can lead to significantly elevated levels of urinary HVA (PMID: 20933512). Likewise, the microbial digestion of hydroxytyrosol (found in olive oil) can also lead to elevated levels of HVA in humans (PMID: 11929304).
Hydrocinnamic acid, also known as 3-phenylpropanoic acid or dihydrocinnamic acid, belongs to the class of organic compounds known as phenylpropanoic acids. Phenylpropanoic acids are compounds with a structure containing a benzene ring conjugated to a propanoic acid (C6-C3). Phenylpropanoic acid can be prepared from cinnamic acid by hydrogenation. Hydrocinnamic acid is a sweet, balsamic, and cinnamon tasting compound. This compound is used frequently in cosmetic products such as perfumes, bath gels, detergent powders, liquid detergents, fabric softeners, and soaps as it gives off a floral scent. A characteristic reaction of phenylpropanoic acid is its cyclization to indanones. Phenylpropanoic acid is used in the food industry to preserve and maintain the original aroma quality of frozen foods. Phenylpropanoic acid is also added to food for technological purposes in a wide variety including manufacturing, processing, preparation, treatment, packaging, transportation or storage, and food additives. This compound is used as a sweetener as well to sweeten food and can be found in tabletop sweeteners.
Quercetin 3-galactoside is found in alcoholic beverages. Quercetin 3-galactoside occurs widely in plants, e.g. in apple peel and Hypericum perforatum (St John's wort).Hyperoside is the 3-O-galactoside of quercetin. It is a medicinally active compound that can be isolated from Drosera rotundifolia, from the Stachys plant, from Prunella vulgaris, from Rumex acetosella and from St John's wort. (Wikipedia
Idarubicin is only found in individuals that have used or taken this drug. It is an orally administered anthracycline antineoplastic. The compound has shown activity against breast cancer, lymphomas and leukemias, together with the potential for reduced cardiac toxicity. [PubChem]Idarubicin has antimitotic and cytotoxic activity through a number of proposed mechanisms of action: Idarubicin forms complexes with DNA by intercalation between base pairs, and it inhibits topoisomerase II activity by stabilizing the DNA-topoisomerase II complex, preventing the religation portion of the ligation-religation reaction that topoisomerase II catalyzes.
Imatinib is a drug used to treat certain types of cancer. It is currently marketed by Novartis as Gleevec (USA) or Glivec (Europe/Australia) as its mesylate salt, imatinib mesilate (INN). It is occasionally referred to as CGP57148B or STI571 (especially in older publications). It is used in treating chronic myelogenous leukemia (CML), gastrointestinal stromal tumors (GISTs) and a number of other malignancies. It is the first member of a new class of agents that act by inhibiting particular tyrosine kinase enzymes, instead of non-specifically inhibiting rapidly dividing cells.
Indirubin or indigo red is an organic compound with a distinctive deep red/orange color. It is an oxindole dimer consisting of two fused oxindole rings. Indoles are compounds which consist of a pyrrole ring fused to benzene to form 2,3-benzopyrrole. Indirubin is found in both plants and animals and has been detected in human urine and human tissues (PMID: 11076521; PMID: 8667928). The precursor to indirubin is indican, a colorless, water-soluble derivative of the amino acid tryptophan which is converted to indole via microbial metabolism. Indican readily hydrolyzes to release β-D-glucose and indoxyl. Oxidation of indoxyl by CYP450 enzymes in the liver or kidneys can convert indoxyl to indirubin (PMID: 11076521). Likewise, exposure to air can convert indoxyl to indirubin. In addition to the mammalian production of minute amounts of indirubin, this chemical can also be recovered in far larger amounts from plants. Historically, indirubin has been extracted from the leaves of certain plants of the Indigofera genus, in particular Indigofera tinctoria. Indigofera plants were commonly grown and used throughout the world for the production of dyes. Indirubin is a chemical constituent of indigo naturalis (also known as qing dai), which has been used for hundreds of years in traditional Chinese medicine. It is produced by collecting the waste products from the bacterial degradation of specific forms of vegetation. Indirubin has shown anti-inflammatory and anti-angiogenesis properties in vitro (PMID: 21207415). It has also been studied for potential use in the treatment of ulcerative colitis (PMID: 23674882).
Indinavir is only found in individuals that have used or taken this drug. It is a potent and specific HIV protease inhibitor that appears to have good oral bioavailability. [PubChem]Indinavir inhibits the HIV viral protease enzyme which prevents cleavage of the gag-pol polyprotein, resulting in noninfectious, immature viral particles.
Indole-3-acetamide, also known as 2-(3-indolyl)acetamide or IAM, belongs to the class of organic compounds known as 3-alkylindoles. 3-Alkylindoles are compounds containing an indole moiety that carries an alkyl chain at the 3-position. Indole-3-acetamide has been detected, but not quantified, in several different foods, such as Alaska wild rhubarbs, lingonberries, butternut squash, pineapples, and agaves. Indole-3-acetamide is also found in the common pea and has been isolated from the etiolated seedlings of the black gram (Phaseolus mungo).
Indole-3-carboxylic acid, also known as 3-carboxyindole or 3-indolecarboxylate, belongs to the class of organic compounds known as indolecarboxylic acids and derivatives. Indolecarboxylic acids and derivatives are compounds containing a carboxylic acid group (or a derivative thereof) linked to an indole. Naphthylmethylindoles: Any compound containing a 1H-indol-3-yl-(1-naphthyl)methane structure with substitution at the nitrogen atom of the indole ring by an alkyl, haloalkyl, alkenyl, cycloalkylmethyl, cycloalkylethyl, 1-(N-methyl-2-piperidinyl)methyl, or 2-(4-morpholinyl)ethyl group whether or not further substituted in the indole ring to any extent and whether or not substituted in the naphthyl ring to any extent. One example given is JWH-250. Outside of the human body, indole-3-carboxylic acid has been detected, but not quantified in several different foods, such as brassicas, broccoli, pulses, common beets, and barley. This could make indole-3-carboxylic acid a potential biomarker for the consumption of these foods. Notice the pentyl group substituted onto the nitrogen atom of the indole ring. Note that this definition encompasses only those compounds that have OH groups attached to both the phenyl and the cyclohexyl rings, and so does not include compounds such as O-1871 which lacks the cyclohexyl OH group, or compounds such as JWH-337 or JWH-344 which lack the phenolic OH group.
Indomethacin is a non-steroidal antiinflammatory agent (NSAIA) with antiinflammatory, analgesic and antipyretic activity. Its pharmacological effect is thought to be mediated through inhibition of the enzyme cyclooxygenase (COX), the enzyme responsible for catalyzes the rate-limiting step in prostaglandin synthesis via the arachidonic acid pathway.
Indoxyl sulfate is a dietary protein metabolite and also a metabolite of the common amino acid tryptophan. It has been identified as a uremic toxin according to the European Uremic Toxin Working Group (PMID: 22626821). It is a circulating uremic toxin stimulating glomerular sclerosis and interstitial fibrosis. Indoxyl sulfate is one of the well-known substances of a group of protein-bound uremic retention solutes. Indoxyl sulfate increases the rate of progression of renal failure. In plasma, indoxyl sulfate is a protein-bound uremic solute that induces endothelial dysfunction by inhibiting endothelial proliferation and migration in vitro. Some studies suggest that indoxyl sulfate is also involved in oxidative stress. In hemodialyzed patients, serum levels of indoxyl sulfate are associated with levels of pentosidine, a marker of carbonyl and oxidative stress. In vitro, indoxyl sulfate increases reactive oxygen species (ROS) production in tubular cells and increases NAD(P)H oxidase activity in endothelial cells. Indoxyl sulfate impairs osteoblast function and induces abnormalities of bone turnover. Indoxyl sulfate strongly decreases the levels of glutathione, one of the most active antioxidant systems of the cell (PMID: 10681668 , 14681860 , 17471003 , 17403109). Indoxyl sulfate is a microbial metabolite found in Escherichia (PMID: 19946322).
Inosinic acid, also known as inosine monophosphate, IMP, 5'-inosinate or 5'-IMP, belongs to the class of organic compounds known as purine ribonucleoside monophosphates. These are nucleotides consisting of a purine base linked to a ribose to which one monophosphate group is attached. IMP is also classified as a nucleotide (a nucleoside monophosphate). Inosinic acid exists in all living species, ranging from bacteria to plants to humans. IMP is widely used as a flavor enhancer. In the food industry it is known as E number reference E630.  Inosinic acid can be converted into various salts including disodium inosinate (E631), dipotassium inosinate (E632), and calcium inosinate (E633). These three inosinate compounds are used as flavor enhancers for the basic taste umami. These inosinate salts are mostly used in soups, sauces, and seasonings for the intensification and balance of the flavor of meat. Inosinic acid is typically obtained from chicken byproducts or other meat industry waste. Inosinic acid or IMP is important in metabolism. It is the ribonucleotide of hypoxanthine and the first nucleotide formed during the synthesis of purine nucleotides. It can also be formed by the deamination of adenosine monophosphate by AMP deaminase.  GMP is formed by the inosinate oxidation to xanthylate (XMP). Within humans, inosinic acid participates in a number of enzymatic reactions. In particular, inosinic acid can be converted into phosphoribosyl formamidocarboxamide; which is catalyzed by the bifunctional purine biosynthesis protein. In addition, inosinic acid can be converted into xanthylic acid; which is catalyzed by the enzyme inosine-5'-monophosphate dehydrogenase 1.
Irbesartan is an angiotensin receptor blocker (ARB) used mainly for the treatment of hypertension. It competes with angiotensin II for binding at the AT1 receptor subtype. Unlike ACE inhibitors, ARBs do not have the adverse effect of dry cough. The use of ARBs is pending revision due to findings from several clinical trials suggesting that this class of drugs may be associated with a small increased risk of cancer.
Irinotecan is an antineoplastic enzyme inhibitor primarily used in the treatment of colorectal cancer. It is a derivative of camptothecin that inhibits the action of topoisomerase I. Irinotecan prevents religation of the DNA strand by binding to topoisomerase I-DNA complex, and causes double-strand DNA breakage and cell death.
Isobutyric acid is a carboxylic or short chain fatty acid with characteristic sweat-like smell. Small amount of isobutyrate is generated via microbial (gut) metabolism. Small amounts may also be found in certain foods or fermented beverages. There is anosmia (genetic inability to smell) for the odor of isobutyric acid with a frequency of about 2.5%. (OMIM 207000). Isobutyric acid is slightly soluble in water but much more soluble in ethanol, ether and organic solvents. Isobutyric acid can affect people if breathed in and may be absorbed through the skin. Contact can irritate and burn the skin and eyes. Breathing Isobutyric acid can irritate the nose, throat and lungs causing coughing, wheezing and/or shortness of breath.
Isoquercitrin is found in alcoholic beverages. Isoquercitrin occurs widely in plants. Isoquercitrin is present in red wine.Isoquercitin can be isolated from mangoes and from Rheum nobile, the Noble rhubarb or Sikkim rhubarb, a giant herbaceous plant native to the Himalaya. Quercetin glycosides are also present in tea. (Wikipedia
Isorhamnetin 3-beta-d-glucoside, also known as isorhamnetin-3-glu, is a member of the class of compounds known as flavonoid-3-o-glycosides. Flavonoid-3-o-glycosides are phenolic compounds containing a flavonoid moiety which is O-glycosidically linked to carbohydrate moiety at the C3-position. Isorhamnetin 3-beta-d-glucoside is slightly soluble (in water) and a very weakly acidic compound (based on its pKa). Isorhamnetin 3-beta-d-glucoside can be synthesized from beta-D-glucose. Isorhamnetin 3-beta-d-glucoside can also be synthesized into isorhamnetin. Isorhamnetin 3-beta-d-glucoside can be found in sea-buckthornberry, which makes isorhamnetin 3-beta-d-glucoside a potential biomarker for the consumption of this food product. Isorhamnetin 3-beta-d-glucoside may be a unique S.cerevisiae (yeast) metabolite.
Isorhamnetin is the methylated metabolite of quercetin. Quercetin is an important dietary flavonoid with in vitro antioxidant activity. However, it is found in human plasma as conjugates with glucuronic acid, sulfate or methyl groups, with no significant amounts of free quercetin present. Isorhamnetin prevents endothelial cell injuries from oxidized LDL via inhibition of lectin-like ox-LDL receptor-1 upregulation, interference of ox-LDL-mediated intracellular signaling pathway (p38MAPK activation, NF-kappaB nuclear translocation, eNOS expression) and the antioxidant activity of isorhamnetin. Isorhamnetin prevents endothelial dysfunction, superoxide production, and overexpression of p47phox induced by angiotensin II. Isorhamnetin appears to be a potent drug against esophageal cancer due to its in vitro potential to not only inhibit proliferation but also induce apoptosis of Eca-109 cells. (PMID: 15493462, 17368593, 17374653, 16963021).
Isoxanthopterin is a pteridine normally present in plasma, urine, and other bodily fluids also vary from normal concentrations in some disease states and also have diagnostic value. Pteridines' urinary concentrations seem to vary independently from each other and from normal values to yield a pattern of excreted pteridines that is diagnostic for different species, tissues, and tumor types. Intravenous or intramuscular administration of isoxanthopterin inhibits the growth rates of animal tumor models. Pteridin derivatives are a family of organic compound with very similar chemical structures which play an important biochemistry role. Pteridines metabolism and its regulation in normal and pathological conditions have not been extensively investigated due to the difficulty of their quantification. A significant decrease of isoxanthopterin has been determined in cancer patients. (PMID 15837549, 9800651). Xanthine dehydrogenase (XDH) is the enzymes responsible for the conversion of xanthine to uric acid. It requires the presence of the molybdenum cofactor for its proper functioning. XDH is reported to have additional functions, i.e., the conversion of pterin to isoxanthopterin, one of the steps the degradation pathway of 5,6,7,8-tetrahydrobiopterin (BH4). Isoxanthopterin is very low in some cases of hereditary xanthinuria (OMIM 278300) and molybdenum cofactor deficiency (OMIM 252150). (PMID: 8812740).
Isradipine belongs to the dihydropyridine (DHP) class of calcium channel blockers (CCBs), the most widely used class of CCBs. It is structurally related to felodipine, nifedipine, and nimodipine and is the most potent calcium-channel blocking agent of the DHP class. Isradipine binds to calcium channels with high affinity and specificity and inhibits calcium flux into cardiac and arterial smooth muscle cells. It exhibits greater selectivity towards arterial smooth muscle cells owing to alternative splicing of the alpha-1 subunit of the channel and increased prevalence of inactive channels in smooth muscle cells. Isradipine may be used to treat mild to moderate essential hypertension.
Kaempferol 3-rhamno-glucoside, also known as nicotiflorin or kaempferol 3-rutinoside, is a member of the class of compounds known as flavonoid-3-o-glycosides. Flavonoid-3-o-glycosides are phenolic compounds containing a flavonoid moiety which is O-glycosidically linked to carbohydrate moiety at the C3-position. Kaempferol 3-rhamno-glucoside is slightly soluble (in water) and a very weakly acidic compound (based on its pKa). Kaempferol 3-rhamno-glucoside can be found in ginkgo nuts and tea, which makes kaempferol 3-rhamno-glucoside a potential biomarker for the consumption of these food products.
Kaempferol, also known as rhamnolutein or c.i. 75640, belongs to the class of organic compounds known as flavonols. Flavonols are compounds that contain a flavone (2-phenyl-1-benzopyran-4-one) backbone carrying a hydroxyl group at the 3-position. Thus, kaempferol is considered to be a flavonoid molecule. A tetrahydroxyflavone in which the four hydroxy groups are located at positions 3, 5, 7 and 4'. Kaempferol is a very hydrophobic molecule, practically insoluble in water, and relatively neutral. Kaempferol exists in all eukaryotes, ranging from yeast to humans. Kaempferol is a bitter tasting compound. Kaempferol is found, on average, in the highest concentration within a few different foods, such as saffrons, capers, and cumins and in a lower concentration in lovages, endives, and cloves. Kaempferol has also been detected, but not quantified, in several different foods, such as shallots, pine nuts, feijoa, kombus, and chicory leaves. This could make kaempferol a potential biomarker for the consumption of these foods. Kaempferol is a potentially toxic compound.
Kynurenine is a metabolite of the amino acid tryptophan used in the production of niacin. L-Kynurenine is a central compound of the tryptophan metabolism pathway since it can change into the neuroprotective agent kynurenic acid or to the neurotoxic agent quinolinic acid. The break-up of these endogenous compounds' balance can be observable in many disorders such as stroke, epilepsy, multiple sclerosis, and amyotrophic lateral sclerosis. It can also occur in neurodegenerative disorders such as Parkinson's disease, Huntington's, and Alzheimer's disease; and in mental disorders such as schizophrenia and depression.
Lactitol is found in herbs and spices. Artificial sweetener used in foods. Sweetness 0.4 x sucrose.Lactitol is a sugar alcohol used as a replacement bulk sweetener for low calorie foods with approximately 40% of the sweetness of sugar. Lactitol is produced by two manufacturers, Danisco and Purac Biochem
Lactulose is a synthetic disaccharide used in the treatment of constipation and hepatic encephalopathy. It has also been used in the diagnosis of gastrointestinal disorders (From Martindale, The Extra Pharmacopoeia, 30th ed, p887). Moreover, lactulose is found to be associated with celiac disease, which is an inborn error of metabolism.
Lamivudine is only found in individuals that have used or taken this drug. It is a reverse transcriptase inhibitor and zalcitabine analog in which a sulfur atom replaces the 3&#39; carbon of the pentose ring. It is used to treat Human Immunodeficiency Virus Type 1 (HIV-1) and hepatitis B (HBV).Lamivudine is a synthetic nucleoside analogue and is phosphorylated intracellularly to its active 5'-triphosphate metabolite, lamivudine triphosphate (L-TP). This nucleoside analogue is incorporated into viral DNA by HIV reverse transcriptase and HBV polymerase, resulting in DNA chain termination.
Laricitrin, also known as 3'-O-methylmyricetin or 3,4',5,5',7-pentahydroxy-3'-methoxyflavone, belongs to the class of organic compounds known as flavonols. Flavonols are compounds that contain a flavone (2-phenyl-1-benzopyran-4-one) backbone carrying a hydroxyl group at the 3-position. Thus, laricitrin is considered to be a flavonoid lipid molecule. Laricitrin is a very hydrophobic molecule, practically insoluble (in water), and relatively neutral. BioTransformer predicts that laricitrin is a product of isorhamnetin metabolism via a hydroxylation-of-benzene-ortho-to-edg reaction catalyzed by the CYP1A2, CYP2C8, CYP2C9, and CYP3A4 enzymes (PMID: 30612223).
Letrozole (INN, trade name Femara) is an oral non-steroidal aromatase inhibitor that has been introduced for the adjuvant treatment of hormonally-responsive breast cancer
Levocetirizine is a second-generation piperazine H1-antihistamine. It has also been labeled as a third-generation antihistamine because it is developed from a second-generation antihistamine (cetirizine).
Linoleic acid is a doubly unsaturated fatty acid, also known as an omega-6 fatty acid, occurring widely in plant glycosides. In this particular polyunsaturated fatty acid (PUFA), the first double bond is located between the sixth and seventh carbon atom from the methyl end of the fatty acid (n-6). Linoleic acid is an essential fatty acid in human nutrition because it cannot be synthesized by humans. It is used in the biosynthesis of prostaglandins (via arachidonic acid) and cell membranes (From Stedman, 26th ed). Linoleic acid is found to be associated with isovaleric acidemia, which is an inborn error of metabolism.
Liquiritigenin is found in alfalfa. Liquiritigenin is isolated from Glycyrrhiza, Medicago, Myroxylon, Cicer, and all Leguminosae species. Several glycosides, particularly rutinoside and neohesperidoside, are important in influencing citrus fruit flavour.
Lorazepam is only found in individuals that have used or taken this drug. It is a benzodiazepine used as an anti-anxiety agent with few side effects. It also has hypnotic, anticonvulsant, and considerable sedative properties and has been proposed as a preanesthetic agent. [PubChem]Lorazepam binds to an allosteric site on GABA-A receptors, which are pentameric ionotropic receptors in the CNS. Binding potentiates the effects of the inhibitory neurotransmitter GABA, which upon binding opens the chloride channel in the receptor, allowing chloride influx and causing hyperpolerization of the neuron.
Losartan is an angiotensin-receptor blocker (ARB) that may be used alone or with other agents to treat hypertension. Losartan and its longer acting metabolite, E-3174, lower blood pressure by antagonizing the renin-angiotensin-aldosterone system (RAAS); they compete with angiotensin II for binding to the type-1 angiotensin II receptor (AT1) subtype and prevents the blood pressure increasing effects of angiotensin II. Unlike angiotensin-converting enzyme (ACE) inhibitors, ARBs do not have the adverse effect of dry cough. Losartan may be used to treat hypertension, isolated systolic hypertension, left ventricular hypertrophy and diabetic nephropathy. It may also be used as an alternative agent for the treatment of systolic dysfunction, myocardial infarction, coronary artery disease, and heart failure.
As most NSAIDs, loxoprofen is a non-selective cyclooxygenase inhibitor, and works by reducing the synthesis of prostaglandins from arachidonic acid. Loxoprofen (INN) is a non-steroidal anti-inflammatory drug in the propionic acid derivatives group, which also includes ibuprofen and naproxen among others. It is marketed in Brazil, Mexico and Japan by Sankyo as its sodium salt, loxoprofen sodium, under the trade name Loxonin, Argentina as Oxeno and in India as Loxomac. It is available in these countries for oral administration, and a transdermal preparation was approved for sale in Japan on January 2006. Loxoprofen is a prodrug. It is quickly converted to its active trans-alcohol metabolite following oral administration, and reaches its peak plasma concentration within 30 to 50 minutes.
Maleic acid is a dicarboxylic acid, a molecule with two carboxyl groups. It consists of an ethylene group flanked by two carboxylic acid groups. Maleic acid is the cis isomer of butenedioic acid, whereas fumaric acid is the trans isomer. The cis isomer is the less stable one of the two; the difference in heat of combustion is 22.7 kJ/mol. The physical properties of maleic acid are very different from that of fumaric acid. Maleic acid is soluble in water whereas fumaric acid is not and the melting point of maleic acid (130 - 131 oC) is also much lower than that of fumaric acid (287 oC). Maleic acid is converted into maleic anhydride by dehydration, to malic acid by hydration, and to succinic acid by hydrogenation. Maleic acid is used in making polyesters for fibre-reinforced laminated moldings and paint vehicles. More specifically it is used in the manufacture of phthalic-type alkyd and polyester resins, surface coatings, copolymers, plasticizers, lubricant additives and agricultural chemicals. It is also found in adhesives and sealants and as a preservative for oils and fats. In the natural world, maleic acid has been identified in ginseng, pineapple, cacao plants, sour cherries and corn. A large number of microbes are able to convert maleic acid to D-malate using the enzyme maleate hydratase (PMID: 1444397).
D-Malic acid is found in herbs and spices. This enantiomer of rare occurrence; reported from fruits and leaves of Hibiscus sabdariffa (roselle) although there are many more isolations of malic acid with no opt. rotn. given and some may be of the R-for
Malonic acid (IUPAC systematic name: propanedioic acid) is a dicarboxylic acid with structure CH2(COOH)2. The ionised form of malonic acid, as well as its esters and salts, are known as malonates. For example, diethyl malonate is malonic acid's ethyl ester. The name originates from Latin malum, meaning apple. Malonic acid is the archetypal example of a competitive inhibitor: it acts against succinate dehydrogenase (complex II) in the respiratory electron transport chain. Malonic acid is found to be associated with malonyl-CoA decarboxylase deficiency, which is an inborn error of metabolism.
Maltotriose is a trisaccharide (three-part sugar) consisting of three glucose molecules linked with α-1,4 glycosidic bonds. It is most commonly produced by the digestive enzyme alpha-amylase (a common enzyme in human saliva) on amylose in starch. The creation of both maltotriose and maltose during this process is due to the random manner in which alpha amylase hydrolyses α-1,4 glycosidic bonds. It is the shortest chain oligosaccharide that can be classified as maltodextrin. Maltotriose belongs to the class of organic compounds known as oligosaccharides. These are carbohydrates made up of 3 to 10 monosaccharide units linked to each other through glycosidic bonds. Maltotriose is a common oligosaccharide metabolite found in human urine after maltose ingestion or infusion (PMID:6645121). Maltotriose is increased in glycogen storage disease II (OMIM: 232300) due to a mutation of the enzyme alpha-1,4-glucosidase (EC 3.2.1.20) (PMID:4286143).
It is an isomer of cresotinic acid (2-hydroxy-3-methylbenzoic acid) and oxymethylbenzoic acid (2-methoxybenzoic acid). Derivatives of mandelic acid are formed as a result of metabolism of adrenaline and noradrenaline by monoamine oxidase and catechol-o-methyl transferase. It is also present in certain skin care products, is an intermediate molecule in the production of other biochemicals, may be used as an analytical reagent and is a precursor in the manufacture of dyes. Mandelic acid is an aromatic alpha hydroxy acid with the molecular formula C8H8O3. It is a white crystalline solid that is soluble in water and most common organic solvents. Mandelic acid is found to be associated with phenylketonuria, which is an inborn error of metabolism.
Mannitol, or hexan-1,2,3,4,5,6-hexol (C6H8(OH)6), is an alcohol and a sugar (sugar alcohol), or a polyol, it is a stereoisomer of sorbitol and is similar to the C5 xylitol. The structure of mannitol is made of a straight chain of six carbon atoms, each of which is substituted with a hydroxyl group. Mannitol is one of the most abundant energy and carbon storage molecules in nature, it is produced by a wide range of organisms such as bacteria, fungi and plants (PMID: 19578847). In medicine, mannitol is used as a diuretic and renal diagnostic aid. Mannitol has little significant energy value as it is largely eliminated from the body before any metabolism can take place. It can be used to treat oliguria associated with kidney failure or other manifestations of inadequate renal function and has been used for determination of glomerular filtration rate. Mannitol is also commonly used as a research tool in cell biological studies, usually to control osmolarity. Mannitol has a tendency to lose a hydrogen ion in aqueous solutions, which causes the solution to become acidic. For this, it is not uncommon to add a weak base, such as sodium bicarbonate, to the solution to adjust its pH. Mannitol is a non-permeating molecule i.e., it cannot cross biological membranes. Mannitol is an osmotic diuretic agent and a weak renal vasodilator. Mannitol is found to be associated with cytochrome c oxidase deficiency and ribose-5-phosphate isomerase deficiency, which are inborn errors of metabolism. Mannitol is also a microbial metabolite found in Aspergillus, Candida, Clostridium, Gluconobacter, Lactobacillus, Lactococcus, Leuconostoc, Pseudomonas, Rhodobacteraceae, Saccharomyces, Streptococcus, Torulaspora and Zymomonas (PMID: 15240312; PMID: 29480337).
Melatonin is a biogenic amine that is found in animals, plants and microbes. Aaron B. Lerner of Yale University is credited for naming the hormone and for defining its chemical structure in 1958. In mammals, melatonin is produced by the pineal gland. The pineal gland is small endocrine gland, about the size of a rice grain and shaped like a pine cone (hence the name), that is located in the center of the brain (rostro-dorsal to the superior colliculus) but outside the blood-brain barrier. The secretion of melatonin increases in darkness and decreases during exposure to light, thereby regulating the circadian rhythms of several biological functions, including the sleep-wake cycle. In particular, melatonin regulates the sleep-wake cycle by chemically causing drowsiness and. lowering the body temperature. Melatonin is also implicated in the regulation of mood,learning and memory, immune activity, dreaming, fertility and reproduction. Melatonin is also an effective antioxidant. Most of the actions of melatonin are mediated through the binding and activation of melatonin receptors. Individuals with autism spectrum disorders(ASD) may have lower than normal levels of melatonin. A 2008 study found that unaffected parents of individuals with ASD also have lower melatonin levels, and that the deficits. were associated with low activity of the ASMT gene, which encodes the last enzyme of melatonin synthesis. Reduced melatonin production has also been proposed as a likely factor in the significantly higher cancer rates in night workers.
Melezitose, also spelled melicitose, is a nonreducing trisaccharide sugar that is produced by many plant sap eating insects, including aphids such as Cinara pilicornis by an enzyme reaction. This is beneficial to the insects, as it reduces the stress of osmosis by reducing their own water potential. The melezitose is part of the honeydew which acts as an attractant for ants and also as a food for bees. This is useful to the lice as they have a symbiotic relationship with ants. Melezitose can be partially hydrolyzed to glucose and turanose the latter of which is an isomer of sucrose (Wikipedia).
Mestranol is only found in individuals that have used or taken this drug. It is the 3-methyl ether of ethinyl estradiol. It must be demethylated to be biologically active. It is used as the estrogen component of many combination ORAL contraceptives. [PubChem]Mestranol is the 3-methyl ether of ethinylestradiol. Ethinylestradiol, is a synthetic derivative of estradiol. Ethinylestradiol is orally bio-active and the estrogen used in almost all modern formulations of combined oral contraceptive pills. It binds to (and activates) the estrogen receptor. Mestranol is a biologically inactive prodrug of ethinylestradiol to which it is demethylated in the liver with a conversion efficiency of 70%.Estrogens diffuse into their target cells and interact with a protein receptor. Target cells include the female reproductive tract, the mammary gland, the hypothalamus, and the pituitary. Estrogens increase the hepatic synthesis of sex hormone binding globulin (SHBG), thyroid-binding globulin (TBG), and other serum proteins and suppress follicle-stimulating hormone (FSH) from the anterior pituitary. The combination of an estrogen with a progestin suppresses the hypothalamic-pituitary system, decreasing the secretion of gonadotropin-releasing hormone (GnRH).
Methionine sulfoxide belongs to the class of organic compounds known as l-alpha-amino acids. These are alpha amino acids which have the L-configuration of the alpha-carbon atom. Methionine sulfoxide exists in all living species, ranging from bacteria to humans. Within humans, methionine sulfoxide participates in a number of enzymatic reactions. In particular, methionine sulfoxide can be biosynthesized from L-methionine through its interaction with the enzyme methionine-R-sulfoxide reductase B3. In addition, methionine sulfoxide can be biosynthesized from L-methionine through the action of the enzyme methionine-R-sulfoxide reductase b2, mitochondrial. In humans, methionine sulfoxide is involved in the metabolic disorder called hypermethioninemia.
Methotrexate is only found in individuals that have used or taken this drug. It is an antineoplastic antimetabolite with immunosuppressant properties. It is an inhibitor of tetrahydrofolate dehydrogenase and prevents the formation of tetrahydrofolate, necessary for synthesis of thymidylate, an essential component of DNA. [PubChem]Methotrexate anti-tumor activity is a result of the inhibition of folic acid reductase, leading to inhibition of DNA synthesis and inhibition of cellular replication. The mechanism involved in its activity against rheumatoid arthritis is not known.
Methyl vanillate is a member of the class of compounds known as m-methoxybenzoic acids and derivatives. These compounds are benzoic acids in which the hydrogen atom at position 3 of the benzene ring is replaced by a methoxy group. Methyl vanillate is considered to be a slightly soluble in water acidic compound. Methyl vanillate can be synthesized from vanillic acid. Vanillic acid is a phenolic acid or chlorogenic acid that is an oxidized form of vanillin. Vanillic acid is also an intermediate in the production of vanillin from ferulic acid. It is found in some forms of vanilla and many other plant extracts. It is a flavouring and scent agent that produces a pleasant, creamy odour. Vanillic acid is also found in wine and vinegar. Vanillic acid is a metabolic by-product of caffeic acid and is often found in the urine of humans who have consumed coffee, chocolate, tea, and vanilla-flavoured confectionary. Vanillic acid selectively and specifically inhibits 5'-nucleotidase activity (PMID:16899266 ). Vanillic acid is also a microbial metabolite found in several bacterial genera including Amycolatopsis, Delftia, and Pseudomonas (PMID:11152072 , 10543794 , 11728709 , 9579070 ). Methyl vanillate has been identified in foods such as cow's milk (PMID:4682334) and beer (PMID:20800742).
Methyl acetate belongs to the class of organic compounds known as carboxylic acid esters. These are carboxylic acid derivatives in which the carbon atom from the carbonyl group is attached to an alkyl or an aryl moiety through an oxygen atom (forming an ester group). Methyl acetate is present in apple, grape, banana and other fruits. Methyl acetate is a flavouring ingredient and it is an ester that, in the laboratory, is synthesized from acetic acid and methanol in the presence of strong acids such as sulfuric acid in an esterification reaction. In the presence of strong bases such as sodium hydroxide or strong acids such as hydrochloric acid or sulfuric acid it is hydrolyzed back into methanol and acetic acid, especially at elevated temperature. Methyl acetate, also known as acetic acid methyl ester or methyl ethanoate, is a clear, flammable liquid with a characteristic, not unpleasant smell like certain glues or nail polish removers. Methyl acetate has characteristics very similar to its analog ethyl acetate. Methyl acetate is used as a solvent in glues, paints, and nail polish removers, in chemical reactions, and for extractions. Methyl acetate is a non-polar (lipophilic) to weakly polar (hydrophilic) aprotic solvent. Methyl acetate has a solubility of 25% in water at room temperature. At elevated temperature its solubility in water is much higher. Methyl acetate is not stable in the presence of strong aqueous bases or acids. The conversion of methyl acetate back into its components, by an acid, is a first-order reaction with respect to the ester. The reaction of methyl acetate and a base, for example sodium hydroxide, is a second-order reaction with respect to both reactants
Miglitol is an oral anti-diabetic drug that acts by inhibiting the ability of the patient to breakdown complex carbohydrates into glucose. It is primarily used in diabetes mellitus type 2 for establishing greater glycemic control by preventing the digestion of carbohydrates (such as disaccharides, oligosaccharides, and polysaccharides) into monosaccharides which can be absorbed by the body. Miglitol inhibits glycoside hydrolase enzymes called alpha-glucosidases. Since miglitol works by preventing digestion of carbohydrates, it lowers the degree of postprandial hyperglycemia. It must be taken at the start of main meals to have maximal effect. Its effect will depend on the amount of non-monosaccharide carbohydrates in a person's diet. In contrast to acarbose (another alpha-glucosidase inhibitor), miglitol is systemically absorbed; however, it is not metabolized and is excreted by the kidneys.
Milrinone is only found in individuals that have used or taken this drug. It is a positive inotropic cardiotonic agent with vasodilator properties. Milrinone inhibits erythrocyte phosphodiesterase, resulting in an increase in erythrocyte cAMP activity. Subsequently, the erythrocyte membrane becomes more resistant to deformity. Along with erythrocyte activity, Milrinone also decreases blood viscosity by reducing plasma fibrinogen concentrations and increasing fibrinolytic activity. It also inhibits cAMP phosphodiesterase activity in myocardium and vascular smooth muscle. Milrinone is a derivative of amrinone and has 20-30 times the ionotropic potency of amrinone. [PubChem]
Galactaric acid, also known as mucic acid or galactarate, belongs to the class of organic compounds known as glucuronic acid derivatives. Glucuronic acid derivatives are compounds containing a glucuronic acid moiety (or a derivative), which consists of a glucose moiety with the C6 carbon oxidized to a carboxylic acid. Technically, galactaric acid is an aldaric acid obtained by oxidation of galactose. Galactaric acid exists as a white crystalline powder, which melts at 210 - 230 oC. It is insoluble in alcohol, and nearly insoluble in cold water (1 g/300 mL) but more soluble in hot water (1 g/60 mL).. Galactaric acid exists in all living organisms, ranging from bacteria to plants to humans. In plants, galactaric acid is commonly produced or utilized as an osmorgulator (PMID: 31505987). Galactaric acid has been detected, but not quantified in, several different foods, such as fruits, vegetables and bovine milk. A recent large-scale dietary study found that galactaric acid can serve as a biomarker for long-term dairy intake and for the consumption of carotenoid-rich vegetables (PMID: 33566801). In food production, galactaric acid can be used to replace tartaric acid in self-rising flour or fizzies.
Myricetin, also known as cannabiscetin or myricetol, belongs to the class of organic compounds known as flavonols. Flavonols are compounds that contain a flavone (2-phenyl-1-benzopyran-4-one) backbone carrying a hydroxyl group at the 3-position. Thus, myricetin is considered to be a flavonoid lipid molecule. A hexahydroxyflavone that is flavone substituted by hydroxy groups at positions 3, 3', 4', 5, 5' and 7. Myricetin is a very hydrophobic molecule, practically insoluble in water, and relatively neutral. Myricetin is found, on average, in the highest concentration within a few different foods, such as common walnuts, carobs, and fennels and in a lower concentration in welsh onions, yellow bell peppers, and jutes. Myricetin has also been detected, but not quantified in several different foods, such as napa cabbages, sesames, mixed nuts, lichee, and garden cress.
Asymmetric dimethylarginine (ADMA) is a naturally occurring chemical found in blood plasma. It is a metabolic by-product of continual protein modification processes in the cytoplasm of all human cells. It is closely related to L-arginine, a conditionally-essential amino acid. ADMA interferes with L-arginine in the production of nitric oxide, a key chemical to endothelial and hence cardiovascular health. Asymmetric dimethylarginine is created in protein methylation, a common mechanism of post-translational protein modification. This reaction is catalyzed by an enzyme set called S-adenosylmethionine protein N-methyltransferases (protein methylases I and II). The methyl groups transferred to create ADMA are derived from the methyl group donor S-adenosylmethionine, an intermediate in the metabolism of homocysteine. (Homocysteine is an important blood chemical, because it is also a marker of cardiovascular disease). After synthesis, ADMA migrates into the extracellular space and thence into blood plasma. Asymmetric dimethylarginine is measured using high performance liquid chromatography. ADMA has been identified as a uremic toxin according to the European Uremic Toxin Working Group (PMID: 22626821).
N,N-Dimethylformamide (DMF) is a clear liquid that has been widely used in industries as a solvent, an additive, or an intermediate because of its extensive miscibility with water and most common organic solvents. Its health effects include hepatotoxicity and male reproductoxicity, possibly linked with mitochondrial DNA (mtDNA) alterations including mtDNA common deletion (delta-mtDNA4977) and mtDNA copy number; during the biotransformation of DMF in the body, free radicals are formed, including hydroxyl radicals. The world-wide consumption of DMF in 2001 was approximately 285,000 metric tonnes and most of that was used as an industrial solvent. Overexposure to DMF could result in hepatotoxicity, alcohol intolerance, possible embryotoxicity and teratogenicity in humans and animals, and decline of human sperm motility. Based on its wide application and a wide range of toxic effects, DMF has been selected as one of the four priority compounds for human field studies by the National Toxicology Program (NTP) of the US National Institute of Environmental Health Sciences (NIEHS). The current permissible exposure limit for DMF in the working environment is 10 ppm in both USA and Taiwan. The concentrations of two major DMF metabolites in urine, N-methylformamide (U-NMF) of 15 mg/L and N-acetyl-S-(N-methylcarbamoyl) cysteine (U-AMCC) of 40 mg/L, were recommended as the biological exposure indices (BEIs) by the American Conference of Governmental Industrial Hygienists for DMF exposure in workplace. (PMID: 17254560).
Dimethylglycine (DMG) is an amino acid derivative found in the cells of all plants and animals and can be obtained in the diet in small amounts from grains and meat. The human body produces DMG when metabolizing choline into glycine. Dimethylglycine that is not metabolized in the liver is transported by the circulatory system to body tissue. Dimethylglycine was popular with Russian athletes and cosmonauts owing to its reputed ability to increase endurance and reduce fatigue. DMG is also a byproduct of homocysteine metabolism. Homocysteine and betaine are converted to methionine and N,N-dimethylglycine by betaine-homocysteine methyltransferase. DMG in the urine is a biomarker for the consumption of legumes. It is also a microbial metabolite (PMID: 25901889).
2-Furoylglycine is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acyl glycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13) which is an enzyme that catalyzes the chemical reaction:. acyl-CoA + glycine < -- > CoA + N-acylglycine. Dietary studies show that 2-Furoylglycine precursors are of exogenous origin. Most probably from furan derivatives found in food prepared by strong heating. This may explain the absence of 2-furoylglycine in urine of breastfed children (PMID 4630229). 2-Furoylglycine is also a microbial metabolite.
N-Acetylaspartylglutamate (NAAG) is a neuropeptide found in millimolar concentrations in the brain that is localized to subpopulations of glutamatergic, cholinergic, GABAergic, and noradrenergic neuronal systems. NAAG is released upon depolarization by a Ca(2+)-dependent process and is an agonist at mGluR3 receptors and an antagonist at NMDA receptors. NAAG is catabolized to N-acetylaspartate and glutamate primarily by glutamate carboxypeptidase II, which is expressed on the extracellular surface of astrocytes. The levels of NAAG and the activity of carboxypeptidase II are altered in a regionally specific fashion in several neuropsychiatric disorders (PMID:9361299). N-Acetylaspartylglutamic acid (NAAG) is a purported precursor of N-acetylaspartic acid (NAA) and is present at about one-tenth of the concentration of NAA in the brain. NAAG has been reported to activate N-methyl-D-aspartic acid (NMDA) receptors in neurons. Previous immunohistochemical studies in the vertebrate central nervous system (CNS) have suggested that NAAG is exclusively localized to neurons. Recent evidence, however, indicates that NAAG might also be localized to nonneuronal cells within the CNS. Only traces of NAA and NAAG are detectable in other tissues. Some compounds can change levels of NAA and NAAG in the brain. For example, methylphenidate increases the levels of NAA and NAAG in the cerebral cortex; amphetamine also increases NAA concentration in a mature brain by 26%, raising the possibility that other neurochemical systems might be involved in the clinical effects of stimulants (PMID:10603234).
N4-Acetylcytidine is a modified nucleoside. N4-acetylcytidine is an endogenous urinary nucleoside product of the degradation of transfer ribonucleic acid (tRNA); urinary nucleosides are biological markers for patients with colorectal cancer. tRNA has been shown to be excreted in abnormal amounts in the urine of cancer patients. tRNA from neoplastic tissue had a much more rapid turnover rate than the tRNA from the corresponding normal tissue. Evidence indicates that methylation of tRNA occurs only after synthesis of the intact macromolecule. Because there are no specific enzyme systems to incorporate the modified nucleosides into the macromolecular nucleic acid, these nucleosides once released in the process of tRNA turnover cannot be reutilized, nor are they further degraded, but are excreted in urine. (PMID: 15991285, 3506820).
N-Acetyl-D-Glucosamine (N-acetlyglucosamine) is a monosaccharide derivative of glucose. Chemically it is an amide between glucosamine and acetic acid. A single N-acetlyglucosamine moiety linked to serine or threonine residues on nuclear and cytoplasmic proteins -O-GlcNAc, is an ubiquitous post-translational protein modification. O-GlcNAc modified proteins are involved in sensing the nutrient status of the surrounding cellular environment and adjusting the activity of cellular proteins accordingly. O-GlcNAc regulates cellular responses to hormones such as insulin, initiates a protective response to stress, modulates a cell's capacity to grow and divide, and regulates gene transcription. In humans, it exists in skin, cartilage and blood vessel as a component of hyaluronic acid, and bone tissue, cornea and aorta as a component of keratan sulfate. (PMID 16237703).
N-Methylhistamine belongs to the class of organic compounds known as aralkylamines. These are alkylamines in which the alkyl group is substituted at one carbon atom by an aromatic hydrocarbyl group.
Cinnamoylglycine is known as a urinary metabolite in man (PMID 649712) although whether it is formed de novo from plant cinnamate or is a plant product excreted. unchanged has not been conclusively demonstrated. When cinnamoylglycine occurs naturally it is probably a food constituent excreted unchanged. It is not found when small quantities (0.5-6 g) of cinnamic acid are fed to man, but by analogy with animal experiments may be produced when much larger quantities are given. (PMID 6743769).
N-formyl-L-methionine is a L-methionine derivative in which one of the hydrogens attached to the nitrogen is replaced by a formyl group. It has a role as a metabolite. It is a proteinogenic amino acid, a N-formyl amino acid and a L-methionine derivative. It is a conjugate acid of a N-formyl-L-methioninate. N-Formyl-L-methionine belongs to the class of organic compounds known as methionine and derivatives. Methionine and derivatives are compounds containing methionine or a derivative thereof resulting from reaction of methionine at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom. N-Formyl-L-methionine is effective in the initiation of protein synthesis. The initiating methionine residue enters the ribosome as N-formylmethionyl-tRNA. This process occurs in Escherichia coli and other bacteria as well as in the mitochondria of eukaryotic cells.
Acetyl-N-formyl-5-methoxykynurenamine (AFMK) results from the oxidative cleavage of the pyrrole ring during melatonin oxidation by myeloperoxidase (MPO), a superoxide anion (O)-dependent reaction. AFMK is also expected to be formed from oxidation catalyzed by the unspecific enzyme indoleamine-2,3-dioxygenase (IDO), found in a variety of cell types including monocyte/macrophage lineages. MPO- and IDO-catalyzed melatonin oxidation has the requirement of O in common, a species formed in large amounts in inflammatory conditions. The non-enzymatic formation of AFMK can also be expected by its direct reaction with highly reactive oxygen species, such as hydroxyl radical and singlet oxygen. Thus, we assume that AFMK is a product formed in a route of melatonin metabolism, especially active in inflammation. As AFMK is biologically more active on leukocytes than melatonin, the metabolizing of melatonin to AFMK at inflammatory sites possibly plays a role in immunomodulation. AFMK is found in the CSF of patients with meningitis, and in some samples at a remarkably high concentration. AFMK was also found in some patients to exceed the concentration of melatonin normally found in serum (PMID: 16150112).
Isobutyrylglycine is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acyl glycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13) which is an enzyme that catalyzes the chemical reaction: acyl-CoA + glycine < -- > CoA + N-acylglycine. Isobutyrylglycine is identified in large amount in urine of patients with isobutyryl-CoA dehydrogenase deficiency. Isobutyryl-CoA dehydrogenase deficiency is a disorder caused by the deficiency of isobutyryl-CoA dehydrogenase that is involved in the catabolism of the branched-chain amino acid valine (PMID 15505379). Moreover, Isobutyrylglycine is found to be associated with ethylmalonic encephalopathy and propionic acidemia, which are also inborn errors of metabolism. Isobutyrylglycine is a biomarker for the consumption of cheese.
Isovalerylglycine (IVG) is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acyl glycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13) which is an enzyme that catalyzes the chemical reaction: acyl-CoA + glycine < -- > CoA + N-acylglycine. Isovalerylglycine is a byproduct of the catabolism of the aminoacid leucine. Accumulation of isovalerylglycine occurs in Isovaleric Acidemia (IVA). IVA (OMIM/ McKusick 243500) is an autosomal recessive disorder caused by mutations in the isovaleryl-CoA dehydrogenase (EC 1.3.99.10) gene. The deficiency of this enzyme in the metabolism of leucine leads to the accumulation of a series of isovaleryl-CoA metabolites, such as isovalerylglycine. It is very important to caution for false positive results when screening for isovaleric acidemia by tandem mass spectrometry based on dried blood-spot levels of C5-acylcarnitines, including isovalerylcarnitine and its isomer, pivaloylcarnitine; pivaloylcarnitine is derived from pivalate-generating antibiotics, and has caused many false-positive results (PMID: 17850781). Isovalerylglycine is a biomarker for the consumption of cheese.
N-Methylalanine, also known as (S)-2-methylaminopropanoate or N-methyl-L-alanine, is classified as an alanine or an alanine derivative. Alanines are compounds containing alanine or a derivative thereof resulting from reaction of alanine at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom. N-Methylalanine is considered to be soluble (in water) and acidic. (ChemoSummarizer)
2-(Methylamino)benzoic acid is found in citrus. 2-(Methylamino)benzoic acid is isolated from grapefruit peel oi
N-Acetylhistamine is a 4-(beta-Acetylaminoethyl)imidazole that is an intermediate in Histidine metabolism. It is generated from Histamine via the enzyme Transferases (EC 2.3.1.-). Histamine is an amine derived by enzymatic decarboxylation of histidine. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter.
N2,N2-Dimethylguanosine is an urinary nucleoside, a primary degradation product of tRNA. The mean levels of urinary N2,N2-Dimethylguanosine in the patients with colorectal cancer are significantly higher than those in patients with intestinal villous adenoma or the healthy adults (PMID 15991285). N2,N2-Dimethylguanosine has been identified in the human placenta (PMID: 32033212).
2-Methylguanosine is an endogenous methylated nucleoside found in human fluids; methylated purine bases are present in higher amounts in tumor-bearing patients compared to healthy controls.DNA hypermethylation is a common finding in malignant cells and has been explored as a therapeutic target for hypomethylating agents. When chemical bonds to DNA, the DNA becomes damaged and proper and complete replication cannot occur to make the normal intended cell. A DNA adduct is an abnormal piece of DNA covalently-bonded to a cancer-causing chemical. This has shown to be the start of a cancerous cell, or carcinogenesis. DNA adducts in scientific experiments are used as bio-markers and as such are themselves measured to reflect quantitatively, for comparison, the amount of cancer in the subject. (PMID: 17336316, 17154124, 3506820, 17044778, 17264127).
Riboprine, also known as isopentenyladenosine or ipa, is a member of the class of compounds known as purine nucleosides. Purine nucleosides are compounds comprising a purine base attached to a ribosyl or deoxyribosyl moiety. Riboprine is slightly soluble (in water) and a very weakly acidic compound (based on its pKa). Riboprine can be found in a number of food items such as peppermint, chinese mustard, custard apple, and green bean, which makes riboprine a potential biomarker for the consumption of these food products.
N6-Methyladenosine is a methylated adenine residue. N6-Methyladenosine is an endogenous urinary nucleoside product of the degradation of transfer ribonucleic acid (tRNA); urinary nucleosides are biological markers for patients with colorectal cancer. tRNA has been shown to be excreted in abnormal amounts in the urine of cancer patients. tRNA from neoplastic tissue had a much more rapid turnover rate than the tRNA from the corresponding normal tissue. Evidence indicates that methylation of tRNA occurs only after synthesis of the intact macromolecule. Because there are no specific enzyme systems to incorporate the modified nucleosides into the macromolecular nucleic acid, these nucleosides once released in the process of tRNA turnover cannot be reutilized, nor are they further degraded, but are excreted in urine. (PMID: 15991285, 3506820).
Naringin, also known as naringoside or naringin hydrate, is a flavanone-7-O-glycoside between the flavanone naringenin and the disaccharide neohesperidose. Naringin belongs to the flavonoid family. Flavonoids consist of 15 carbon atoms in 3 rings, 2 of which must be benzene rings connected by a 3 carbon chain.  Naringin contains the basic flavonoid structure along with one rhamnose and one glucose unit attached to its aglycone portion, called naringenin, at the 7-carbon position. The steric hindrance provided by the two sugar units makes naringin less potent than its aglycone counterpart, naringenin. Naringin is a bitter tasting compound. Naringin is found, on average, in the highest concentration within a few different foods, such as rosemaries, grapefruit/pummelo hybrids, and grapefruits and in a lower concentration in grape wines, pummelo, and beers. Naringin has also been detected, but not quantified in several different foods, such as citrus, limes, herbs and spices, common oregano, and mandarin orange (clementine, tangerine). Both naringin and hesperetin, which are the aglycones of naringin and hesperidin, occur naturally in citrus fruits. Naringin is the major flavonoid glycoside in grapefruit and gives grapefruit juice its bitter taste. Narinigin exerts a variety of pharmacological effects such as antioxidant activity, blood lipid-lowering, anticarcinogenic activity, and inhibition of selected cytochrome P450 enzymes including CYP3A4 and CYP1A2, which may result in several drug interactions in-vitro.
Nelfinavir is only found in individuals that have used or taken this drug. It is a potent HIV-1 protease inhibitor. It is used in combination with other antiviral drugs in the treatment of HIV in both adults and children. [PubChem]Nelfinavir inhibits the HIV viral proteinase enzyme which prevents cleavage of the gag-pol polyprotein, resulting in noninfectious, immature viral particles.
Nervonic acid is a long chain unsaturated fatty acid that is enriched in sphingomyelin. It consists of choline, sphingosine, phosphoric acid, and fatty acid. Nervonic acid may enhance the brain functions and prevent demyelination (Chemical Land21). Research shows that there is negative relationship between nervonic acid and obesity-related risk factors (PMID:16394593). Demyelination in adrenoleukodystrophy (ALD) is associated with an accumulation of very long chain saturated fatty acids stemming from a genetic defect in the peroxisomal beta oxidation system responsible for the chain shortening of these fatty acids. Sphingolipids from post mortem ALD brain have decreased levels of nervonic acid, 24:1(n-9), and increased levels of stearic acid, 18:0. (PMID:8072429).
Nicotinic acid, also known as niacin or vitamin B3, is a water-soluble vitamin whose derivatives such as NADH, NAD, NAD+, and NADP play essential roles in energy metabolism in the living cell and DNA repair. The designation vitamin B3 also includes the amide form, nicotinamide or niacinamide. Severe lack of niacin causes the deficiency disease pellagra, whereas a mild deficiency slows down the metabolism decreasing cold tolerance. The recommended daily allowance of niacin is 2-12 mg a day for children, 14 mg a day for women, 16 mg a day for men, and 18 mg a day for pregnant or breast-feeding women. It is found in various animal and plant tissues and has pellagra-curative, vasodilating, and antilipemic properties. The liver can synthesize niacin from the essential amino acid tryptophan, but the synthesis is extremely slow and requires vitamin B6; 60 mg of tryptophan are required to make one milligram of niacin. Bacteria in the gut may also perform the conversion but are inefficient.
Nicotinuric acid is an acylglycine. Acylglycines are normally minor metabolites of fatty acids. However, the excretion of certain acylglycines is increased in several inborn errors of metabolism. In certain cases, the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acylglycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13) which is an enzyme that catalyzes the chemical reaction acyl-CoA + glycine <-> CoA + N-acylglycine. Nicotinuric acid is the major detoxification product of nicotinic acid. It may serve as a simple quantitative index of hepatic biotransformation of nicotinic acid (PMID:3243933).
Nimodipine is a 1,4-dihydropyridine calcium channel blocker. It acts primarily on vascular smooth muscle cells by stabilizing voltage-gated L-type calcium channels in their inactive conformation. By inhibiting the influx of calcium in smooth muscle cells, nimodipine prevents calcium-dependent smooth muscle contraction and subsequent vasoconstriction. Compared to other calcium channel blocking agents, nimodipine exhibits greater effects on cerebral circulation than on peripheral circulation. Nimodipine is used to as an adjunct to improve the neurologic outcome following subarachnoid hemorrhage from ruptured intracranial aneurysm.
Nitazoxanide, also known by the brand name Alinia, is a synthetic nitrothiazolyl-salicylamide derivative and an anti-protozoal agent. It is approved for treatment of infectious diarrhea caused by Cryptosporidium parvum and Giardia lamblia in patients 1 year of age and older. Following oral administration it is rapidly hydrolyzed to its active metabolite, tizoxanide, which is 99% protein bound. Peak concentrations are observed 1-4 hours after administration. It is excreted in the urine, bile and feces. Untoward effects include abdominal pain, vomiting and diarrhea. [Wikipedia]
Nitrazepam is only found in individuals that have used or taken this drug. It is a benzodiazepine derivative used as an anticonvulsant and hypnotic.Nitrazepam belongs to a group of medicines called benzodiazepines. It acts on benzodiazepine receptors in the brain which are associated with the GABA receptors causing an enhanced binding of GABA (gamma amino butyric acid) to GABAA receptors. GABA is a major inhibitory neurotransmitter in the brain, involved in inducing sleepiness, muscular relaxation and control of anxiety and fits, and slows down the central nervous system. The anticonvulsant properties of nitrazepam and other benzodiazepines may be in part or entirely due to binding to voltage-dependent sodium channels rather than benzodiazepine receptors. Sustained repetitive firing seems to be limited by benzodiazepines effect of slowing recovery of sodium channels from inactivation.
Nitrendipine is only found in individuals that have used or taken this drug. It is a calcium channel blocker with marked vasodilator action. It is an effective antihypertensive agent and differs from other calcium channel blockers in that it does not reduce glomerular filtration rate and is mildly natriuretic, rather than sodium retentive. [PubChem]By deforming the channel, inhibiting ion-control gating mechanisms, and/or interfering with the release of calcium from the sarcoplasmic reticulum, Nitrendipine inhibits the influx of extracellular calcium across the myocardial and vascular smooth muscle cell membranes The decrease in intracellular calcium inhibits the contractile processes of the myocardial smooth muscle cells, causing dilation of the coronary and systemic arteries, increased oxygen delivery to the myocardial tissue, decreased total peripheral resistance, decreased systemic blood pressure, and decreased afterload.
Nizatidine is only found in individuals that have used or taken this drug. It is a histamine H2 receptor antagonist with low toxicity that inhibits gastric acid secretion. The drug is used for the treatment of duodenal ulcers. [PubChem]Nizatidine competes with histamine for binding at the H<sub>2</sub>-receptors on the gastric basolateral membrane of parietal cells. Competitive inhibition results in reduction of basal and nocturnal gastric acid secretions. The drug also decreases the gastric acid response to stimuli such as food, caffeine, insulin, betazole, or pentagastrin.
Norepinephrine is the precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers and of the diffuse projection system in the brain arising from the locus ceruleus. It is also found in plants and is used pharmacologically as a sympathomimetic. Norepinephrine is elevated in the urine of people who consume bananas. Norepinephrine is also a microbial metabolite; urinary noradrenaline is produced by Escherichia, Bacillus, and Saccharomyces (PMID: 24621061). Norepinephrine is found in alcoholic beverages, banana peels and pulp (Musa paradisiaca), red plum fruit (Prunus domestica), orange pulp (Citrus sinensis), potato tubers (Solanum tuberosum), and whole purslane (Portulaca oleracea). P. oleracea is the richest of these sources. Norepinephrine has also been identified as a uremic toxin according to the European Uremic Toxin Working Group (PMID: 22626821).
L-Norleucine, also known as L-aminohexanoate or caprine, belongs to the class of organic compounds known as l-alpha-amino acids. These are alpha amino acids which have the L-configuration of the alpha-carbon atom. Thus, L-norleucine is considered to be a fatty acid lipid molecule. An unnatural amino acid that is used experimentally to study protein structure and function. L-Norleucine is a very hydrophobic molecule, practically insoluble in water, and relatively neutral. L-Norleucine exists in all eukaryotes, ranging from yeast to humans. Outside of the human body, L-Norleucine has been detected, but not quantified in cow milk. This could make L-norleucine a potential biomarker for the consumption of these foods. It binds reversibly to the kringle domain of plasminogen and blocks the binding of plasminogen to fibrin and its activation to plasmin.
O-Phosphoethanolamine, also known as PEA, phosphorylethanolamine, colamine phosphoric acid or ethanolamine O-phosphate, belongs to the class of organic compounds known as phosphoethanolamines. Phosphoethanolamines are compounds containing a phosphate linked to the second carbon of an ethanolamine. O-Phosphoethanolamine is used in the biosynthesis of two different types of phospholipids: glycerophospholipids and sphingolipids. O-Phosphoethanolamine exists in all living species, ranging from bacteria to plants to humans. Within humans, O-phosphoethanolamine participates in a number of enzymatic reactions. In particular, cytidine triphosphate and O-phosphoethanolamine can be converted into CDP-ethanolamine; which is mediated by the enzyme ethanolamine-phosphate cytidylyltransferase. In addition, O-phosphoethanolamine can be biosynthesized from ethanolamine; which is catalyzed by the enzyme choline/ethanolamine kinase. In humans, O-phosphoethanolamine is involved in phosphatidylcholine biosynthesis. O-phosphoethanolamine is also a product of the metabolism of sphingolipids. In particular, sphinglipids are metabolized in vivo to phosphorylethanolamine and a fatty aldehyde, generally palmitaldehyde. Both metabolites are ultimately converted to glycerophospholipids. The lipids are first phosphorylated by a kinase and then cleaved by the pyridoxal-dependent sphinganine-1-phosphate aldolase. Elevated urine levels of O-Phosphoethanolamine or PEA can be used to help in the diagnosis of Hypophosphatasia (HPP). Reference ranges for urinary PEA vary according to age and somewhat by diet, and follow a circadian rhythm. Outside of the human body, O-phosphoethanolamine has been detected, but not quantified in, several different foods, such as oxheart cabbages, anises, shiitakes, abalones, and teffs.
Phosphoserine is the phosphoric acid ester of the amino acid serine. It is found in essentially all living organisms ranging from microbes to plants to mammals. Phosphoserine is a component of many proteins as the result of posttranslational modifications to the native protein‚Äôs serine residue(s). The phosphorylation of the hydroxyl functional group in serine to produce phosphoserine is catalyzed by various types of kinases. Serine is one of three amino acid residues that are commonly phosphorylated by kinases during cell signalling in eukaryotes. Free phosphoserine is found in many biofluids and likely arises from the proteolysis of proteins containing phosphoserine residues (PMID: 7693088).
Phosphothreonine is a phosphoamino acid. It is the phosphorylated ester of threonine. There are three amino acids that are typically phosphorylated in eukaryotes: serine, threonine, and tyrosine. Threonine residues in endogenous proteins undergo phosphorylation through the action of a threonine kinase. Small amounts of free phosphothreonine can be detected in urine [PMID: 7693088].
Octadecanedioic acid, also known as 1,18-octadecanedioate or octadecane-1,18-dioate, belongs to the class of organic compounds known as long-chain fatty acids. These are fatty acids with an aliphatic tail that contains between 13 and 21 carbon atoms. In the case of octadecanedioic acid, it has carboxyl groups at both ends of the chain, not just one.  Octadecanedioic acid is a very hydrophobic molecule, practically insoluble (in water).  Octadecanedioic acid is a long-chain dicarboxylic acid normally not found in humans that has been identified in the blood serum in Reye's syndrome patients (PMID:¬†3746531).  There may also be an association with colorectal cancer (PMID: 25037050).
Oleic acid (or 9Z)-Octadecenoic acid) is an unsaturated C-18 or an omega-9 fatty acid that is the most widely distributed and abundant fatty acid in nature. It occurs naturally in various animal and vegetable fats and oils. It is an odorless, colorless oil, although commercial samples may be yellowish. The name derives from the Latin word oleum, which means oil. Oleic acid is the most abundant fatty acid in human adipose tissue, and the second most abundant in human tissues overall, following palmitic acid. Oleic acid is a component of the normal human diet, being a part of animal fats and vegetable oils. Triglycerides of oleic acid represent the majority of olive oil (about 70%). Oleic acid triglycerides also make up 59‚Äì75% of pecan oil, 61% of canola oil, 36‚Äì67% of peanut oil, 60% of macadamia oil, 20‚Äì80% of sunflower oil, 15‚Äì20% of grape seed oil, sea buckthorn oil, 40% of sesame oil, and 14% of poppyseed oil. High oleic variants of plant sources such as sunflower (~80%) and canola oil (70%) also have been developed. consumption has been associated with decreased low-density lipoprotein (LDL) cholesterol, and possibly with increased high-density lipoprotein (HDL) cholesterol, however, the ability of oleic acid to raise HDL is still debated. Oleic acid may be responsible for the hypotensive (blood pressure reducing) effects of olive oil that is considered a health benefit. Oleic acid is used in manufacturing of surfactants, soaps, plasticizers. It is also used as an emulsifying agent in foods and pharmaceuticals. Oleic acid is used commercially in the preparation of oleates and lotions, and as a pharmaceutical solvent.
Olmesartan is an antihypertensive agent which belongs to the class of medicines called angiotensin II receptor antagonists. It acts rapidly to lower high blood pressure. It is marketed worldwide by Daiichi Sankyo, Ltd. and in the United States by Daiichi Sankyo, Inc. and Forest Laboratories.
Used to treat allergic conjunctivitis (itching eyes), olopatadine inhibits the release of histamine from mast cells. It is a relatively selective histamine H1 antagonist that inhibits the in vivo and in vitro type 1 immediate hypersensitivity reaction including inhibition of histamine induced effects on human conjunctival epithelial cells.
Omeprazole is a highly effective inhibitor of gastric acid secretion used in the therapy of stomach ulcers, dyspepsia, peptic ulcer disease , gastroesophageal reflux disease and Zollinger-Ellison syndrome. The drug inhibits the H(+)-K(+)-ATPase (H(+)-K(+)-exchanging ATPase) in the proton pump of Gastric Parietal Cells.--Pubchem. Omeprazole is one of the most widely prescribed drugs internationally and is available over the counter in some countries.
Orlistat is a drug designed to treat obesity. Its primary function is preventing the absorption of fats from the human diet, thereby reducing caloric intake. Orlistat works by inhibiting pancreatic lipase, an enzyme that breaks down triglycerides in the intestine. Without this enzyme, triglycerides from the diet are prevented from being hydrolyzed into absorbable free fatty acids and are excreted undigested.
Oxalacetic acid, also known as oxaloacetic acid, keto-oxaloacetate or 2-oxobutanedioate, belongs to the class of organic compounds known as short-chain keto acids and derivatives. These are keto acids with an alkyl chain the contains less than 6 carbon atoms. Oxalacetic acid is a metabolic intermediate in many processes that occur in animals and plants. It takes part in gluconeogenesis, the urea cycle, the glyoxylate cycle, amino acid synthesis, fatty acid synthesis and the citric acid cycle. Oxalacetic acid exists in all living species, ranging from bacteria to plants to humans. Within humans, oxalacetic acid participates in a number of enzymatic reactions. In particular, oxalacetic acid is an intermediate of the citric acid cycle, where it reacts with acetyl-CoA to form citrate, catalyzed by citrate synthase. It is also involved in gluconeogenesis and the urea cycle. In gluconeogenesis oxaloacetate is decarboxylated and phosphorylated by phosphoenolpyruvate carboxykinase and becomes 2-phosphoenolpyruvate using guanosine triphosphate (GTP) as phosphate source. In the urea cycle, malate is acted on by malate dehydrogenase to become oxaloacetate, producing a molecule of NADH. After that, oxaloacetate can be recycled to aspartate, as this recycling maintains the flow of nitrogen into the cell. In mice, injections of oxalacetic acid have been shown to promote brain mitochondrial biogenesis, activate the insulin signaling pathway, reduce neuroinflammation and activate hippocampal neurogenesis (PMID: 25027327). Oxalacetic acid has also been reported to reduce hyperglycemia in type II diabetes and to extend longevity in C. elegans (PMID: 25027327). Outside of the human body, oxalacetic acid has been detected, but not quantified in, several different foods, such as Persian limes, lemon balms, wild rice, canola, and peanuts. This could make oxalacetic acid a potential biomarker for the consumption of these foods.
Oxaprozin is only found in individuals that have used or taken this drug. It is a non-narcotic, non-steroidal anti-inflammatory drug (NSAID), used to relieve the inflammation, swelling, stiffness, and joint pain associated with osteoarthritis and rheumatoid arthritis.Anti-inflammatory effects of Oxaprozin are believed to be due to inhibition of cylooxygenase in platelets which leads to the blockage of prostaglandin synthesis. Antipyretic effects may be due to action on the hypothalamus, resulting in an increased peripheral blood flow, vasodilation, and subsequent heat dissipation. Oxaprozin is a non-selective NSAID, with a cell assay system showing lower COX-2 selectivity implying higher COX-1 selectivity.
Oxazepam is only found in individuals that have used or taken this drug. It is an intermediate-acting benzodiazepine used to treat alcohol withdrawal and anxiety disorders. It is a metabolite of diazepam, prazepam, temazepam, and clorazepate, and has moderate amnesic, anxiolytic, anticonvulsant, hypnotic, sedative, and skeletal muscle relaxant properties compared to other benzodiazepines (Wikipedia). Like other benzodiazepines, oxazepam exerts its anxiolytic effects by potentiating the effect of gamma-aminobutyric acid (GABA) on GABA-A receptors through a cooperative mechanism of action. GABA receptors are ionotropic chloride-linked channel receptors that produce inhibitory postsynaptic potentials. When activated by GABA, the GABA receptor/chloride ionophore complex undergoes a conformational change that allows the passage of chloride ions through the channel. Benzodiazepines are believed to exert their effect by increasing the effect of GABA at its receptor. Benzodiazepine binding increases chloride conductance in the presence of GABA by increasing the frequency at which the channel opens. In contrast, barbiturates increase chloride conductance in the presence of GABA by prolonging the time in which the channel remains open. There are 18 subtypes of the GABA receptor subunits. The &alpha;<sub>2</sub> subunit of the &alpha;<sub>2</sub>&beta;<sub>3</sub>&gamma;<sub>2</sub> receptor complex is thought to mediate anxiolytic effects while the &alpha;<sub>1</sub> subunit of the &alpha;<sub>1</sub>&beta;<sub>2</sub>&gamma;<sub>2</sub> receptor complex is thought to mediate sedative, anticonvulsant, and anterograde amnesia effects.
p-Anisic acid, also known as 4-anisate or draconic acid, belongs to the class of organic compounds known as p-methoxybenzoic acids and derivatives. These are benzoic acids in which the hydrogen atom at position 4 of the benzene ring is replaced by a methoxy group. p-Anisic acid is a drug. p-Anisic acid exists in all eukaryotes, ranging from yeast to humans. p-Anisic acid is a faint, sweet, and cadaverous tasting compound. Outside of the human body, p-anisic acid has been detected, but not quantified in several different foods, such as anises, cocoa beans, fennels, and german camomiles. This could make p-anisic acid a potential biomarker for the consumption of these foods. It is a white crystalline solid which is insoluble in water, highly soluble in alcohols and soluble in ether, and ethyl acetate. p-Anisic acid has antiseptic properties. It is also used as an intermediate in the preparation of more complex organic compounds. It is generally obtained by the oxidation of anethole or p-methoxyacetophenone. The term "anisic acid" often refers to this form specifically. p-Anisic acid is found naturally in anise.
4-Hydroxycinnamic acid, also known as p-Coumaric acid, is a coumaric acid in which the hydroxy substituent is located at C-4 of the phenyl ring. It has a role as a plant metabolite. It is a conjugate acid of a 4-coumarate. p-coumaric acid is an organic compound that is a hydroxy derivative of cinnamic acid. There are three isomers of coumaric acid: o-coumaric acid, m-coumaric acid, and p-coumaric acid, that differ by the position of the hydroxy substitution of the phenyl group. p-Coumaric acid is the most abundant isomer of the three in nature. p-Coumaric acid exists in two forms trans-p-coumaric acid and cis-p-coumaric acid. It is a crystalline solid that is slightly soluble in water, but very soluble in ethanol and diethyl ether. 4-Hydroxycinnamic acid belongs to the class of organic compounds known as hydroxycinnamic acids. Hydroxycinnamic acids are compounds containing an cinnamic acid where the benzene ring is hydroxylated. 4-Hydroxycinnamic acid exists in all living species, ranging from bacteria to humans. Outside of the human body, 4-Hydroxycinnamic acid is found, on average, in the highest concentration within a few different foods, such as pepper (Capsicum frutescens), pineapples, and sunflowers and in a lower concentration in spinachs, kiwis, and sweet oranges. 4-Hydroxycinnamic acid has also been detected, but not quantified in several different foods, such as wild rices, soursops, garden onions, hyssops, and avocado.
p-Toluenesulfonic acid, also known as tosylate or para-toluene sulfonate, is a member of the class of compounds known as p-methylbenzenesulfonates. p-Methylbenzenesulfonates are benzenesulfonic acids (or derivative thereof) carrying a methyl group at the para- position. p-Toluenesulfonic acid is slightly soluble (in water) and an extremely strong acidic compound (based on its pKa). p-Toluenesulfonic acid (PTSA or pTsOH) or tosylic acid (TsOH) is an organic compound with the formula CH3C6H4SO3H. It is a white solid that is soluble in water, alcohols, and other polar organic solvents. The CH3C6H4SO2– group is known as the tosyl group and is often abbreviated as Ts or Tos. Most often, TsOH refers to the monohydrate, TsOH•H2O. It is a white solid that is soluble in water, alcohols, and other polar organic solvents (Wikipedia).
Palmitic acid, or hexadecanoic acid, is one of the most common saturated fatty acids found in animals, plants, and microorganisms. As its name indicates, it is a major component of the oil from the fruit of oil palms (palm oil). Excess carbohydrates in the body are converted to palmitic acid. Palmitic acid is the first fatty acid produced during fatty acid synthesis and is the precursor to longer fatty acids. As a consequence, palmitic acid is a major body component of animals. In humans, one analysis found it to make up 21–30% (molar) of human depot fat (PMID: 13756126), and it is a major, but highly variable, lipid component of human breast milk (PMID: 352132). Palmitic acid is used to produce soaps, cosmetics, and industrial mould release agents. These applications use sodium palmitate, which is commonly obtained by saponification of palm oil. To this end, palm oil, rendered from palm tree (species Elaeis guineensis), is treated with sodium hydroxide (in the form of caustic soda or lye), which causes hydrolysis of the ester groups, yielding glycerol and sodium palmitate. Aluminium salts of palmitic acid and naphthenic acid were combined during World War II to produce napalm. The word "napalm" is derived from the words naphthenic acid and palmitic acid (Wikipedia). Palmitic acid is also used in the determination of water hardness and is a surfactant of Levovist, an intravenous ultrasonic contrast agent.
Pantozol; Pantoprazole (brand names Pantopan in Italy; Protium; Protonix; Pantozol; Pantor; Pantoloc) is a proton pump inhibitor drug used for short-term treatment of erosion and ulceration of the esophagus caused by gastroesophageal reflux disease. Initial treatment is generally of eight weeks' duration, after which another eight week course of treatment may be considered if necessary. It can be used as a maintenance therapy for long term use after initial response is obtained; Pantoprazole is a proton pump inhibitor drug used for short-term treatment of erosion and ulceration of the esophagus caused by gastroesophageal reflux disease. Initial treatment is generally of eight weeks' duration, after which another eight week course of treatment may be considered if necessary. It can be used as a maintenance therapy for long term use after initial response is obtained. Pantoprazole is metabolized in the liver by the cytochrome P450 system. Metabolism mainly consists of demethylation by CYP2C19 followed by sulfation. Another metabolic pathway is oxidation by CYP3A4. Pantoprazole metabolites are not thought to have any pharmacological significance; Protium; Pantor; Pantoloc) is a proton pump inhibitor drug used for short-term treatment of erosion and ulceration of the esophagus caused by gastroesophageal reflux disease. Initial treatment is generally of eight weeks' duration, after which another eight week course of treatment may be considered if necessary. It can be used as a maintenance therapy for long term use after initial response is obtained; Protonix; Pantoprazole (brand names Pantopan in Italy.
Pantothenic acid, also called vitamin B5, is a water-soluble vitamin required to sustain life. Pantothenic acid is needed to form coenzyme-A (CoA), and is thus critical in the metabolism and synthesis of carbohydrates, proteins, and fats. Its name is derived from the Greek pantothen meaning "from everywhere" and small quantities of pantothenic acid are found in nearly every food, with high amounts in whole grain cereals, legumes, eggs, meat, and royal jelly. Pantothenic acid is classified as a member of the secondary alcohols. Secondary alcohols are compounds containing a secondary alcohol functional group, with the general structure HOC(R)(R') (R,R'=alkyl, aryl). Pantothenic acid is considered to be soluble (in water) and acidic.
Parabanic Acid, also known as Parabanate or 2,4,5-Imidazolidinetrione, is classified as a member of the Imidazolinones. Imidazolinones are organic compounds containing an imidazolinone moiety, which is an imidazoline ring bearing a ketone. Parabanic Acid is considered to be soluble (in water) and acidic.  Parabanic Acid can be synthesized from imidazolidine. Parabanic Acid can be synthesized into 1-(2-phenylethyl)imidazolidine-2,4,5-trione
Paraoxon is an acetylcholinesterase inhibitor. It is an organophosphate oxon, and the active metabolite of the insecticide parathion. It is also used as an opthamological drug against glaucoma. Paraoxon is one of the most potent acetylcholinesterase-inhibiting insecticides available, around 70% as potent as the nerve agent sarin, and so is now rarely used as an insecticide due to the risk of poisoning to humans and other animals. It is easily absorbed through skin, and was used as an assassination weapon by the apartheid-era South African chemical weapons program Project Coast.
Penciclovir is only found in individuals that have used or taken this drug. It is a guanine analogue antiviral drug used for the treatment of various herpesvirus infections. It is a nucleoside analogue which exhibits low toxicity and good selectivity. [Wikipedia]Penciclovir has <i>in vitro</i> activity against herpes simplex virus types 1 (HSV-1) and 2 (HSV-2). In cells infected with HSV-1 or HSV-2, viral thymidine kinase phosphorylates penciclovir to a monophosphate form. The monophosphate form of the drug is then converted to penciclovir triphosphate by cellular kinases. The intracellular triphosphate of penciclovir is retained <i>in vitro</i> inside HSV-infected cells for 10-20 hours, compared with 0.7-1 hour for acyclovir. <i>in vitro</i> studies show that penciclovir triphosphate selectively inhibits viral DNA polymerase by competing with deoxyguanosine triphosphate. Inhibition of DNA synthesis of virus-infected cells inhibits viral replication. In cells not infected with HSV, DNA synthesis is unaltered. Resistant mutants of HSV can occur from qualitative changes in viral thymidine kinase or DNA polymerase. The most commonly encountered acyclovir-resistant mutants that are deficient in viral thymidine kinase are also resistant to penciclovir.
Phenylacetylglutamine is a product formed from the conjugation of phenylacetate and glutamine. Technically, it is the amino acid acetylation product of phenylacetate (or phenylbutyrate after beta-oxidation). Phenylacetylglutamine is a normal constituent of human urine, but other mammals such as the dog, cat, rat, monkey, sheep, and horse do not excrete this compound. Phenylacetyl-CoA and L-glutamine react to form phenylacetylglutamine and coenzyme A. The enzyme (glutamine N-acetyl transferase) that catalyzes this reaction has been purified from human liver mitochondria and shown to be a polypeptide species distinct from glycine-N-acyltransferase. Phenylacetylglutamine is a major nitrogenous metabolite that accumulates in uremia (PMID: 2791363, 8972626). It has been shown that over 50% of urine phenylacetylglutamine may be derived from kidney conjugation of free plasma phenylacetic acid and/or from the kidney's preferential filtration of conjugated phenylacetic acid (PMID: 6420430). Phenylacetylglutamine is a microbial metabolite found in Christensenellaceae, Lachnospiraceae and Ruminococcaceae (PMID: 26241311).
Phenylacetylglycine is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acyl glycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13) which is an enzyme that catalyzes the chemical reaction:. acyl-CoA + glycine < -- > CoA + N-acylglycine. Phenylacetylglycine or PAG is a glycine conjugate of phenylacetic acid. Phenylacetic acid may arise from exposure to styrene (plastic) or through the consumption of fruits and vegetables. Phenylacetic acid is used in some perfumes, possessing a honey-like odour in low concentrations, and is also used in penicillin G production. PAG is a putative biomarker of phospholipidosis. Urinary PAG is elevated in animals exhibiting abnormal phospholipid accumulation in many tissues and may thus be useful as a surrogate biomarker for phospholipidosis. (PMID: 15764292) The presence of phenylacetylglycine in urine has been confirmed for dogs, rats and mice. However, the presence of this compound in human urine is controversial. GC-MS studies have not found this compound (PMID: 7492634) while NMR studies claimed to have identified it (PMID: 21167146). It appears that phenylacetylglycine may sometimes be mistaken for phenylacetylglutamine via NMR.
Phloretin is the aglucone of phlorizin, a plant-derived dihydrochalcone phytochemical reported to promote potent antioxidative activities in peroxynitrite scavenging and the inhibition of lipid peroxidation. Phloretin, which is present in apples, pears and tomatoes, has been found to inhibit the growth of several cancer cells and induce apoptosis of B16 melanoma and HL60 human leukemia cells. Phloretin also inhibits HT-29 cell growth by inducing apoptosis, which may be mediated through changes in mitochondrial membrane permeability and activation of the caspase pathways. Phloretin is a well-known inhibitor of eukaryotic urea transporters, blocks VacA-mediated urea and ion transport (PMID:18158826, 11560962, 18063724, 15671209, 12083758). Phloretin is a biomarker for the consumption of apples. Phloretin has been found to be a metabolite of Escherichia (PMID:23542617).
Phloroglucinol is a benzenetriol. It is an organic compound that is used in the synthesis of pharmaceuticals and explosives. This molecule exists in two forms, or tautomers, 1,3,5-trihydroxybenzene, which has phenol-like, and 1,3,5-cyclohexanetrione (phloroglucin), which has ketone-like character. These two tautomers are in equilibrium. Phloroglucinol is a useful intermediate because it is polyfunctional. 1,3,5-Trihydroxybenzene has been found to be a metabolite in Pseudomonas (PMID: 15826166).
Phosphoenolpyruvate (PEP) is an important chemical compound in biochemistry. It has a high energy phosphate bond, and is involved in glycolysis and gluconeogenesis. In glycolysis, PEP is formed by the action of the enzyme enolase on 2-phosphoglycerate. Metabolism of PEP to pyruvate by pyruvate kinase (PK) generates 1 molecule of adenosine triphosphate (ATP) via substrate-level phosphorylation. ATP is one of the major currencies of chemical energy within cells. In gluconeogenesis, PEP is formed from the decarboxylation of oxaloacetate and hydrolysis of 1 guanosine triphosphate molecule. This reaction is catalyzed by the enzyme phosphoenolpyruvate carboxykinase (PEPCK). This reaction is a rate-limiting step in gluconeogenesis. (wikipedia).
Fosfomycin is only found in individuals that have used or taken this drug. It is an antibiotic produced by Streptomyces fradiae. [PubChem]Fosfomycin is a phosphoenolpyruvate analogue produced by Streptomyces that irreversibly inhibits enolpyruvate transferase (MurA), which prevents the formation of N-acetylmuramic acid, an essential element of the peptidoglycan cell wall.
Phthalic acid is an aromatic dicarboxylic acid, with formula C6H4(COOH)2. Phthalic acid is used mainly in the form of the anhydride to produce other chemicals such as dyes, perfumes, saccharin, phthalates and many other useful products. Phthalic acid, when found in tissues or biofluids arises from exposure to these phthalate products. Phthalate is an environmental chemical of heightened public concern because reports of its potential risk to male reproductive health (PMID 16804814), being significantly associated with reduced sperm concentration to pesticide concentration in men's urine (PMID 16804812). Within the reproductive tract, the male is exquisitely vulnerable to the effects of anti-androgens during development due the reliance on the synthesis and action of androgens for the masculinization of the male reproductive tract. The ability of phthalates to suppress androgen synthesis during development and to induce testicular dysgenesis together with cryptorchidism and hypospadias has raised considerable concern. (PMID 15016950).
3,3',4'5-Tetrahydroxystilbene (or Piceatannol) is a phenolic stilbenoid. It is a metabolite of resveratrol found in red wine. A viral protein-tyrosine kinase (LMP2A) implicated in leukemia, non-Hodgkin's lymphoma and other diseases associated with Epstein-Barr virus, was recently found to be blocked by picetannol in vitro (PMID 2590224). Therefore there is research interest in piceatannol as an anti-cancer and anti-EBV drug. Piceatannol can also act as an agonist for estrogen receptor alpha in human breast cancer cells (PMID: 16216908).
trans-Piceid is found in alcoholic beverages. trans-Piceid is present in grapeskins and red wine. It is isolated from Polygonum cuspidatum (Japanese knotweed).Piceid is a stilbenoid glucoside and is a major resveratrol derivative in grape juices
Pimelic acid, also known as heptanedioic acid is a dicarboxylic acid.  Derivatives of pimelic acid are involved in the biosynthesis of the amino acid called lysine. Pimelic acid is one methylene longer than a related dicarboxylic acid, adipic acid, a precursor to many polyesters and polyamides. Pimelic acid is essential for the synthesis of biotin (also called vitamin B7). Biotin is a heterocyclic, S-containing monocarboxylic acid that is made from two precursors, alanine and pimeloyl-CoA. Biotin is important in fatty acid synthesis, branched-chain amino acid catabolism, and gluconeogenesis. Biotin is found in a wide range of foods. Likewise, intestinal bacteria synthesize biotin, which is then absorbed by the host animal. Pimelic acid (which is the precursor for pimeloyl-CoA) is synthesized in many bacteria via a head-to-tail incorporation of acetate units through a modified fatty acid synthetic pathway using O-methyl esters disguised to resemble the canonical intermediates of the fatty acid synthetic pathway (PMID:21435937). Some bacteria and yeast synthesize pimelic acid not by biosynthesis, but via cleavage of longer chain fatty acids (such as linolenic acid) via a cytochrome P450-like enzyme (PMID:28196402, 21435937, 3236079). Pimelic acid is excreted in elevated amounts in the urine of individuals with mitochondrial beta-oxidation disorders and peroxisomal beta oxidation disorders (PMID:1527989)
Pioglitazone is used for the treatment of diabetes mellitus type 2. Pioglitazone selectively stimulates nuclear receptor peroxisone proliferator-activated receptor gamma (PPAR-gamma). It modulates the transcription of the insulin-sensitive genes involved in the control of glucose and lipid metabolism in the lipidic, muscular tissues and in the liver.
Piroxicam is only found in individuals that have used or taken this drug. It is a cyclooxygenase inhibiting, non-steroidal anti-inflammatory agent (NSAID) that is well established in treating rheumatoid arthritis and osteoarthritis and used for musculoskeletal disorders, dysmenorrhea, and postoperative pain. Its long half-life enables it to be administered once daily. [PubChem]The antiinflammatory effect of Piroxicam may result from the reversible inhibition of cyclooxygenase, causing the peripheral inhibition of prostaglandin synthesis. The prostaglandins are produced by an enzyme called Cox-1. Piroxicam blocks the Cox-1 enzyme, resulting into the disruption of production of prostaglandins. Piroxicam also inhibits the migration of leukocytes into sites of inflammation and prevents the formation of thromboxane A2, an aggregating agent, by the platelets.
Most statins are metabolised in part by one or more hepatic cytochrome P450 enzymes, leading to an increased potential for drug interactions and problems with certain foods (such as grapefruit juice). Pitavastatin appears to be a substrate of CYP2C9, and not CYP3A4 (which is a common source of interactions in other statins). As a result, pitavastatin is less likely to interact with drugs that are metabolized via CYP3A4, which might be important for elderly patients who need to take multiple medicines. Pitavastatin (usually as a calcium salt) is a member of the medication class of statins, marketed in the United States under the trade name Livalo. Like other statins, it is an inhibitor of HMG-CoA reductase, the enzyme that catalyses the first step of cholesterol synthesis. It has been available in Japan since 2003, and is being marketed under licence in South Korea and in India. It is likely that pitavastatin will be approved for use in hypercholesterolaemia (elevated levels of cholesterol in the blood) and for the prevention of cardiovascular disease outside South and Southeast Asia as well.
Porphobilinogen (PBG) is a pyrrole-containing intermediate in the biosynthesis of porphyrins. It is generated from aminolevulinate (ALA) by the enzyme ALA dehydratase. Porphobilinogen is then converted into hydroxymethylbilane by the enzyme porphobilinogen deaminase (also known as hydroxymethylbilane synthase). Under certain conditions, porphobilinogen can act as a phototoxin, a neurotoxin, and a metabotoxin. A phototoxin leads to cell damage upon exposure to light. A neurotoxin causes damage to nerve cells and nerve tissues. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Chronically high levels of porphyrins are associated with porphyrias such as porphyria variegate, acute intermittent porphyria, and hereditary coproporphyria (HCP). There are several types of porphyrias (most are inherited). Hepatic porphyrias are characterized by acute neurological attacks (seizures, psychosis, extreme back and abdominal pain, and an acute polyneuropathy), while the erythropoietic forms present with skin problems (usually a light-sensitive blistering rash and increased hair growth). The neurotoxicity of porphyrins may be due to their selective interactions with tubulin, which disrupt microtubule formation and cause neural malformations (PMID: 3441503).
Pravastatin is a member of the drug class of statins, used for lowering cholesterol and preventing cardiovascular disease. Pravastatin was identified originally in a mold called Nocardia autotrophica by researchers of the Sankyo Pharma Inc; An antilipemic fungal metabolite isolated from cultures of Nocardia autotrophica. It acts as a competitive inhibitor of HMG CoA reductase (hydroxymethylglutaryl CoA reductases); In medicine and pharmacology, pravastatin (Pravachol or Selektine) is a member of the drug class of statins, used for lowering cholesterol and preventing cardiovascular disease.
Prolylhydroxyproline is a dipeptide. Prolylhydroxyproline is a marker of bone collagen degradation, showing high sensitivity for the diagnosis of osteoporosis. Prolylhydroxyproline has been suggested as a possible alternative to hydroxyproline determination in bone resorption studies. Prolylhydroxyproline is one of the iminodipeptides present in the urine of patients with prolidase deficiency. Prolidase (X-Pro dipeptidase EC 3.4.13.9) splits iminodipeptides containing C-terminal proline or hydroxyproline (X-Pro or X-Hyp) to X+Pro or X+Hyp. Prolidase deficiency is a rare autosomal recessive disease characterized by chronic ulcerative dermatitis and mental retardation. These patients excrete large amounts of iminodipeptides containing C-terminal proline in the urine due to hereditary prolidase deficiency (PMID: 12636053, 11863289, 2387877, 1874885, 9586797).
Pseudouridine, also known as psi-uridine or 5-ribosyluracil, belongs to the class of organic compounds known as nucleoside and nucleotide analogues. These are analogues of nucleosides and nucleotides, such as phosphonated nucleosides, C-glycosylated nucleoside bases, analogues where the sugar unit is a pyranose, and carbocyclic nucleosides.  Pseudouridine specifically has its uracil attached via a carbon-carbon instead of a nitrogen-carbon glycosidic bond to the ribofuranose.  It is the most prevalent of the over one hundred different modified nucleosides found in RNA (PMID: 17113994).  Pseudouridine is a solid that is soluble in water.  Pseudouridine exists in all living species, ranging from bacteria to humans, and is in all classes of RNA except mRNA.  It is formed by enzymes called pseudouridine synthases, which post-transcriptionally isomerize specific uridine residues in RNA.
Purine, also known as purine base or 1H-purine, belongs to the class of organic compounds known as purines and purine derivatives. These are aromatic heterocyclic compounds containing a purine moiety, which is formed a pyrimidine-ring ring fused to an imidazole ring. Two of the bases in nucleic acids, adenine and guanine, are purines. Purines from food (or from tissue turnover) are metabolised by several enzymes, including xanthine oxidase, into uric acid. Purine exists in all living species, ranging from bacteria to humans. High levels of uric acid can predispose to gout when the acid crystalises in joints; this phenomenon only happens in humans and some animal species (e.g. dogs) that lack an intrinsic uricase enzyme that can further degrade uric acid. In humans, purine is involved in thioguanine action pathway. Outside of the human body, purine is found, on average, in the highest concentration within cocoa beans. Purine has also been detected, but not quantified in several different foods, such as rapinis, plains prickly pears, blackcurrants, radish, and parsley. This could make purine a potential biomarker for the consumption of these foods. Purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring.
Pyridoxal phosphate, also known as PLP, pyridoxal 5'-phosphate or P5P, is the active form of vitamin B6. It is a coenzyme in a variety of enzymatic reactions. Pyridoxal 5'-phosphate belongs to the class of organic compounds known as pyridoxals and derivatives. Pyridoxals and derivatives are compounds containing a pyridoxal moiety, which consists of a pyridine ring substituted at positions 2,3,4, and 5 by a methyl group, a hydroxyl group, a carbaldehyde group, and a hydroxymethyl group, respectively. Pyridoxal 5'-phosphate is a drug which is used for nutritional supplementation and for treating dietary shortage or imbalance. Pyridoxal 5'-phosphate exists in all living species, ranging from bacteria to humans. In humans, pyridoxal 5'-phosphate is involved in glycine and serine metabolism. Outside of the human body, pyridoxal 5'-phosphate is found, on average, in the highest concentration within cow milk. Pyridoxal 5'-phosphate has also been detected, but not quantified in several different foods, such as soursops, italian sweet red peppers, muscadine grapes, european plums, and blackcurrants. Pyridoxal 5'-phosphate, with regard to humans, has been found to be associated with several diseases such as epilepsy, early-onset, vitamin B6-dependent, odontohypophosphatasia, pyridoxamine 5-prime-phosphate oxidase deficiency, and hypophosphatasia. Pyridoxal 5'-phosphate has also been linked to the inborn metabolic disorder celiac disease.
Pyridoxine, also known vitamin B6, is commonly found in food and is used as a dietary supplement. Pyridoxine is an essential nutrient, meaning the body cannot synthesize it, and it must be obtained from the diet. Sources in the diet include fruit, vegetables, and grain. Although pyridoxine and vitamin B6 are still frequently used as synonyms, especially by medical researchers, this practice is sometimes misleading (PMID: 2192605). Technically, pyridoxine is one of the compounds that can be called vitamin B6 or it is a member of the family of B6 vitamins. Healthy human blood levels of pyridoxine are 2.1 - 21.7 ng/mL. Pyridoxine is readily converted to pyridoxal phosphate which is a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids and aminolevulinic acid. Pyridoxine assists in the balancing of sodium and potassium as well as promoting red blood cell production. Therefore pyridoxine is required by the body to make amino acids, carbohydrates, and lipids. It is linked to cancer immunity and helps fight the formation of homocysteine. It has been suggested that pyridoxine might help children with learning difficulties, and may also prevent dandruff, eczema, and psoriasis. In addition, pyridoxine can help balance hormonal changes in women and aid in immune system. Lack of pyridoxine may cause anemia, nerve damage, seizures, skin problems, and sores in the mouth (Wikipedia). Deficiency of pyridoxine, though rare because of widespread distribution in foods, leads to the development of peripheral neuritis in adults and affects the central nervous system in children (DOSE - 3rd edition). As a supplement pyridoxine is used to treat and prevent pyridoxine deficiency, sideroblastic anaemia, pyridoxine-dependent epilepsy, certain metabolic disorders, problems from isoniazid, and certain types of mushroom poisoning. Pyridoxine in combination with doxylamine is used as a treatment for morning sickness in pregnant women.
Pyrrole-2-carboxylic acid was synthesized over a century ago, but its history as a compound of biological origin is rather recent. It was first identified as a degradation product of sialic acids, then as a derivative of the oxidation of the D-hydroxyproline isomers by mammalian D-amino acid oxidase. The latter relationship results from the lability of the direct oxidation product, A'-pyrroline-4-hydroxy-2-carboxylic acid, which loses water spontaneously to form the pyrrole. A similar reaction is catalyzed by the more specific allohydroxy-D-proline oxidase of Pseudomonas. In whole animal observations, pyrrole-2-carboxylate (PCA) ' was identified in rat or human urine after administration of the D-isomers of hydroxyproline, a finding ascribable to the action of D-amino acid oxidase. (PMID:4430715). Urinary excretion of N-(pyrrole-2-carboxyl) glycine has been reported in a 5-year-old affected with type II hyperprolinemia; The child has mild developmental delay, recurrent seizures of the grand mal type and EEG alterations. The urinary excretion of the conjugate is stressed, since it appears that only one previous report in the literature described this compound in the urine of two patients affected by this disturbance (PMID 2383933).
Pyruvic acid or pyruvate is a simple alpha-keto acid. It is a three-carbon molecule containing a carboxylic acid group and a ketone functional group. Pyruvate is the simplest alpha-keto acid and according to official nomenclature by IUPAC, it is called alpha-keto propanoic acid. Like other keto acids, pyruvic acid can tautomerize from its ketone form to its enol form, containing a double bond and an alcohol. Pyruvate is found in all living organisms ranging from bacteria to plants to humans. It is intermediate compound in the metabolism of carbohydrates, proteins, and fats. Pyruvate is a key intermediate in several metabolic pathways throughout the cell. In particular, pyruvic acid can be made from glucose through glycolysis, converted back to carbohydrates (such as glucose) via gluconeogenesis, or to fatty acids through a reaction with acetyl-CoA. Pyruvic acid supplies energy to cells through the citric acid cycle (TCA or Krebs cycle) when oxygen is present (aerobic respiration), and alternatively ferments to produce lactate when oxygen is lacking (lactic acid). In glycolysis, phosphoenolpyruvate (PEP) is converted to pyruvate by pyruvate kinase. This reaction is strongly exergonic and irreversible. In gluconeogenesis, it takes two enzymes, pyruvate carboxylase and PEP carboxykinase, to catalyze the reverse transformation of pyruvate to PEP. Pyruvic acid is also a metabolite of Corynebacterium (PMID: 27872963).
Quercetin 3-O-(6''-acetyl-glucoside) is a polyphenol compound found in foods of plant origin  (PMID: 20428313)
Raffinose is a complex carbohydrate. It is a trisaccharide composed of galactose, fructose, and glucose. It can be found in beans, cabbage, brussels sprouts, broccoli, asparagus, other vegetables, and whole grains. Raffinose is hydrolyzed to D-galactose and sucrose by D-galactosidase (D-GAL). D-GAL also hydrolyzes other D-galactosides such as stachyose, verbascose, and galactinol [1-O-(D-galactosyl)-myoinositol], if present. The enzyme does not cleave linked galactose, as in lactose. Raffinose is also known as melitose and may be thought of as galactose and sucrose connected via an alpha(1->6) glycosidic linkage. Thus, raffinose can be broken down into galactose and sucrose via the enzyme alpha-galactosidase. Human intestines do not contain this enzyme. Raffinose is a trisaccharide occurring in Australian manna (from Eucalyptus spp, Myrtaceae) and in cottonseed meal.
Raltitrexed is only found in individuals that have used or taken this drug. It is a chemotherapy drug manufactured AstraZeneca Company, is an antimetabolite used in chemotherapy. It is an inhibitor of thymidylate synthase.Raltitrexed is an antineoplastic Agents and folic acid antagonists. Raltitrexed inhibits thymidylate synthase (TS) leading to DNA fragmentation and cell death. It is transported into cells via a reduced folate carrier. Inside the cell Raltitrexed is extensively polyglutamated, which enhances thymidylate synthase inhibitory power and duration. Inhibition of this enzyme results in decreased synthesis of thymidine triphosphate which is required for DNA synthesis.
Ramipril is a prodrug belonging to the angiotensin-converting enzyme (ACE) inhibitor class of medications. It is metabolized to ramiprilat in the liver and, to a lesser extent, kidneys. Ramiprilat is a potent, competitive inhibitor of ACE, the enzyme responsible for the conversion of angiotensin I (ATI) to angiotensin II (ATII). ATII regulates blood pressure and is a key component of the renin-angiotensin-aldosterone system (RAAS). Ramipril may be used in the treatment of hypertension, congestive heart failure, nephropathy, and to reduce the rate of death, myocardial infarction and stroke in individuals at high risk of cardiovascular events.
Ranitidine (CAS: 66357-35-5) is a non-imidazole blocker of histamine receptors that mediate gastric secretion (H2 receptors). It is used to treat gastrointestinal ulcers (PubChem). Ranitidine is a histamine H2-receptor antagonist that inhibits stomach acid production and is commonly used in the treatment of peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD). It is currently marketed by GlaxoSmithKline under the trade name Zantac (Wikipedia).
Repaglinide is an oral antihyperglycemic agent used for the treatment of non-insulin-dependent diabetes mellitus (NIDDM). It belongs to the meglitinide class of short-acting insulin secretagogues, which act by binding to cells of the pancreas to stimulate insulin release. Repaglinide induces an early insulin response to meals decreasing postprandial blood glucose levels. It should only be taken with meals and meal-time doses should be skipped with any skipped meal. Approximately one month of therapy is required before a decrease in fasting blood glucose is seen. Meglitnides may have a neutral effect on weight or cause a slight increase in weight. The average weight gain caused by meglitinides appears to be lower than that caused by sulfonylureas and insulin and appears to occur only in those naive to oral antidiabetic agents. Due to their mechanism of action, meglitinides may cause hypoglycemia although the risk is thought to be lower than that of sulfonylureas since their action is dependent on the presence of glucose. In addition to reducing postprandial and fasting blood glucose, meglitnides have been shown to decrease glycosylated hemoglobin (HbA1c) levels, which are reflective of the last 8-10 weeks of glucose control. Meglitinides appear to be more effective at lowering postprandial blood glucose than metformin, sulfonylureas and thiazolidinediones. Repaglinide is extensively metabolized in the liver and excreted in bile. Repaglinide metabolites do not possess appreciable hypoglycemic activity. Approximately 90% of a single orally administered dose is eliminated in feces and 8% in urine.
Resveratrol is a polyphenolic phytoalexin. It is also classified as a stilbenoid, a derivate of stilbene, and is produced in plants with the help of the enzyme stilbene synthase. The levels of resveratrol found in food vary greatly. Red wine contains between 0.2 and 5.8 mg/L depending on the grape variety, while white wine has much less. The reason for this difference is that red wine is fermented with grape skins, allowing the wine to absorb the resveratrol, whereas white wine is fermented after the skin has been removed. Resveratrol is also sold as a nutritional supplement. A number of beneficial health effects, such as anti-cancer, antiviral, neuroprotective, anti-aging, anti-inflammatory, and life-prolonging effects have been reported for resveratrol. The fact that resveratrol is found in the skin of red grapes and as a constituent of red wine may explain the "French paradox". This paradox is based on the observation that the incidence of coronary heart disease is relatively low in southern France despite high dietary intake of saturated fats. Resveratrol is thought to achieve these cardioprotective effects by a number of different routes: (1) inhibition of vascular cell adhesion molecule expression; (2) inhibition of vascular smooth muscle cell proliferation; (3) stimulation of endothelial nitric oxide synthase (eNOS) activity; (4) inhibition of platelet aggregation; and (5) inhibition of LDL peroxidation (PMID: 17875315, 14676260, 9678525). Resveratrol is a biomarker for the consumption of grapes and raisins.
Riboflavin or vitamin B2 is an easily absorbed, water-soluble micronutrient with a key role in maintaining human health. Like the other B vitamins, it supports energy production by aiding in the metabolizing of fats, carbohydrates, and proteins. Vitamin B2 is also required for red blood cell formation and respiration, antibody production, and for regulating human growth and reproduction. It is essential for healthy skin, nails, hair growth and general good health, including regulating thyroid activity. Riboflavin is found in milk, eggs, malted barley, liver, kidney, heart, and leafy vegetables. Riboflavin is yellow or orange-yellow in color and in addition to being used as a food coloring it is also used to fortify some foods. It can be found in baby foods, breakfast cereals, sauces, processed cheese, fruit drinks and vitamin-enriched milk products. The richest natural source is yeast. It occurs in the free form only in the retina of the eye, in whey, and in urine; its principal forms in tissues and cells are as flavin mononucleotide and flavin adenine dinucleotide.
D-Ribose 5-phosphate (CAS: 4300-28-1), also known as R-5-P, belongs to the class of organic compounds known as pentose phosphates. These are carbohydrate derivatives containing a pentose substituted by one or more phosphate groups. D-Ribose 5-phosphate exists in all living species, ranging from bacteria to humans. Within humans, D-ribose 5-phosphate participates in a number of enzymatic reactions. In particular, D-ribose 5-phosphate can be biosynthesized from D-ribulose 5-phosphate; which is mediated by the enzyme ribose-5-phosphate isomerase. In addition, D-ribose 5-phosphate can be biosynthesized from D-ribose; which is catalyzed by the enzyme ribokinase. Outside of the human body, D-ribose 5-phosphate has been detected, but not quantified in cow milk and rices. D-Ribose 5-phosphate is both a product and an intermediate of the pentose phosphate pathway. The last step of the oxidative reactions in the pentose phosphate pathway is the production of ribulose 5-phosphate. D-Ribose 5-phosphate is an important intermediate metabolite in the pentose phosphate pathway and in the purine metabolism pathway. The intracellular ribose 5-phosphate concentration is an important determinant of the rate of de novo purine synthesis (PMID:6699001).
Riluzole is only found in individuals that have used or taken this drug. It is a glutamate antagonist (receptors, glutamate) used as an anticonvulsant (anticonvulsants) and to prolong the survival of patients with amyotrophic lateral sclerosis. [PubChem]The mode of action of riluzole is unknown. Its pharmacological properties include the following, some of which may be related to its effect: 1) an inhibitory effect on glutamate release (activation of glutamate reuptake), 2) inactivation of voltage-dependent sodium channels, and 3) ability to interfere with intracellular events that follow transmitter binding at excitatory amino acid receptors.
Ritonavir is only found in individuals that have used or taken this drug. It is an HIV protease inhibitor that works by interfering with the reproductive cycle of HIV. [PubChem]Ritonavir inhibits the HIV viral proteinase enzyme which prevents cleavage of the gag-pol polyprotein, resulting in noninfectious, immature viral particles.
Rosiglitazone is an anti-diabetic drug from the thiazolidinedione class. Like other thiazolidinediones, its mechanism of action is by activation of the intracellular receptor class of the peroxisome proliferator-activated receptors (PPARs), specifically PPAR-gamma. Rosiglitazone is a pure ligand of PPAR-gamma, and has no PPAR-alpha-binding action. Apart from its effect on insulin resistance, it appears to have an anti-inflammatory effect: nuclear factor kappa-B (NF&#954;B) levels fall and inhibitor (I&#954;B) levels increase in patients on rosiglitazone (Mohanty et al). It increases glyceroneogenesis and reduces the release of free fatty acids from adipocytes; Rosiglitazone is an anti-diabetic drug from the thiazolidinedione class. It is being marketed as Avandia by the pharmaceutical company GlaxoSmithKline, both as a standalone preparation and in combination with metformin (Avandamet). Another combination drug approved by the FDA is Avandaryl (with glimepiride); Like other thiazolidinediones, its mechanism of action is by activation of the intracellular receptor class of the peroxisome proliferator-activated receptors (PPARs), specifically PPAR-gamma. Rosiglitazone is a pure ligand of PPAR-gamma, and has no PPAR-alpha binding action. Apart from its effect on insulin resistance, it appears to have an anti-inflammatory effect: nuclear factor kappa-B (NFkB) levels fall and inhibitor (IkB) levels increase in patients on rosiglitazone (Mohanty et al). It increases glyceroneogenesis and reduces the release of free fatty acids from adipocytes.
Rutin is a flavonoid known to have a variety of biological activities including antiallergic, anti-inflammatory, antiproliferative, and anticarcinogenic properties. A large number of flavonoids, mostly O-glycosides, are polyphenolic compounds of natural origin that are present in most fruits and vegetables. The average intake of the compounds by humans on a normal diet is more than 1 g per day. Although flavonoids are devoid of classical nutritional value, they are increasingly viewed as beneficial dietary components that act as potential protectors against human diseases such as coronary heart disease, cancers, and inflammatory bowel disease. Rutin acts as a quercetin deliverer to the large intestine; moreover, quercetin is extensively metabolized in the large intestine, which suggests that quercetin liberated from rutin and/or its colonic metabolites may play a role. Rutin's anti-inflammatory actions are mediated through a molecular mechanism that underlies the quercetin-mediated therapeutic effects: quercetin-mediated inhibition of tumor necrosis factor-alpha (TNF-alpha)-induced nuclear factor kappa B (NFkB) activation. TNF-alpha-induced NFkB activity plays a central role in the production of pro-inflammatory mediators involved in progression of gut inflammation. (PMID:16132362).
Salicin, also known as salicoside or delta-salicin, is an aryl beta-D-glucoside that is salicyl alcohol in which the phenolic hydrogen has been replaced by a beta-D-glucosyl residue. It has a role as a prodrug, an antipyretic, a non-narcotic analgesic, a non-steroidal anti-inflammatory drug, an EC 1.14.99.1 (prostaglandin-endoperoxide synthase) inhibitor and a metabolite. It is an aryl beta-D-glucoside, an aromatic primary alcohol and a member of benzyl alcohols. It derives from a salicyl alcohol.  Salicin belongs to the class of organic compounds known as phenolic glycosides. These are organic compounds containing a phenolic structure attached to a glycosyl moiety. Some examples of phenolic structures include lignans, and flavonoids. Among the sugar units found in natural glycosides are D-glucose, L-Fructose, and L rhamnose. Salicin exists in all living organisms, ranging from bacteria to humans. Salicin is a bitter tasting compound.
Salicylic acid is a monohydroxybenzoic acid that is benzoic acid with a hydroxy group at the ortho position. It is obtained from the bark of the white willow and wintergreen leaves. It has a role as an antiinfective agent, an antifungal agent, a keratolytic drug, an EC 1.11.1.11 (L-ascorbate peroxidase) inhibitor, a plant metabolite, an algal metabolite and a plant hormone. It is a conjugate acid of a salicylate. It is a colorless solid, it is a precursor to and a metabolite of aspirin (acetylsalicylic acid). It is a plant hormone. The name is from Latin salix for willow tree. It is an ingredient in some anti-acne products. Salts and esters of salicylic acid are known as salicylates. Salicylic acid modulates COX1 enzymatic activity to decrease the formation of pro-inflammatory prostaglandins. Salicylate may competitively inhibit prostaglandin formation. Salicylate's antirheumatic (nonsteroidal anti-inflammatory) actions are a result of its analgesic and anti-inflammatory mechanisms. Salicylic acid works by causing the cells of the epidermis to slough off more readily, preventing pores from clogging up, and allowing room for new cell growth. Salicylic acid inhibits the oxidation of uridine-5-diphosphoglucose (UDPG) competitively with nicotinamide adenosine dinucleotide and noncompetitively with UDPG. It also competitively inhibits the transferring of glucuronyl group of uridine-5-phosphoglucuronic acid to the phenolic acceptor. The wound-healing retardation action of salicylates is probably due mainly to its inhibitory action on mucopolysaccharide synthesis. Salicylic acid is biosynthesized from the amino acid phenylalanine. In Arabidopsis thaliana, it can be synthesized via a phenylalanine-independent pathway.
2-Hydroxybenzyl alcohol (CAS Number 90-01-7) is a stable light brown crystalline powder.
Salmeterol is only found in individuals that have used or taken this drug. It is a long-acting beta2-adrenergic receptor agonist drug that is currently prescribed for the treatment of asthma and chronic obstructive pulmonary disease COPD. Salmeterol's long, lipophilic side chain binds to exosites near beta(2)-receptors in the lungs and on bronchiolar smooth muscle, allowing the active portion of the molecule to remain at the receptor site, continually binding and releasing. Beta(2)-receptor stimulation in the lung causes relaxation of bronchial smooth muscle, bronchodilation, and increased bronchial airflow.
Sarcosine is the N-methyl derivative of glycine. Sarcosine is metabolized to glycine by the enzyme sarcosine dehydrogenase, while glycine-N-methyl transferase generates sarcosine from glycine. Sarcosine is a natural amino acid found in muscles and other body tissues. In the laboratory it may be synthesized from chloroacetic acid and methylamine. Sarcosine is naturally found in the metabolism of choline to glycine. Sarcosine is sweet to the taste and dissolves in water. It is used in manufacturing biodegradable surfactants and toothpastes as well as in other applications. Sarcosine is ubiquitous in biological materials and is present in such foods as egg yolks, turkey, ham, vegetables, legumes, etc. Sarcosine is formed from dietary intake of choline and from the metabolism of methionine, and is rapidly degraded to glycine. Sarcosine has no known toxicity, as evidenced by the lack of phenotypic manifestations of sarcosinemia, an inborn error of sarcosine metabolism. Sarcosinemia can result from severe folate deficiency because of the folate requirement for the conversion of sarcosine to glycine (Wikipedia). Sarcosine has recently been identified as a biomarker for invasive prostate cancer. It was found to be greatly increased during prostate cancer progression to metastasis and could be detected in urine. Sarcosine levels were also increased in invasive prostate cancer cell lines relative to benign prostate epithelial cells (PMID: 19212411).
Scopoletin is found in anise. Scopoletin is isolated from Angelica acutiloba (Dong Dang Gui
Secobarbital is only found in individuals that have used or taken this drug. It is a barbiturate derivative drug. It possesses anaesthetic, anticonvulsant, sedative and hypnotic properties. In the United Kingdom, it was known as Quinalbarbitone. Secobarbital binds at a distinct binding site associated with a Cl<sup>-</sup> ionopore at the GABA<sub>A</sub> receptor, increasing the duration of time for which the Cl<sup>-</sup> ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged.
Secoisolariciresinol is a lignan, a type of phenylpropanoids.
Shikimic acid, more commonly known as its anionic form shikimate, is a cyclohexene, a cyclitol and a cyclohexanecarboxylic acid. It is an important biochemical intermediate in plants and microorganisms. Its name comes from the Japanese flower shikimi (the Japanese star anise, Illicium anisatum), from which it was first isolated. Shikimic acid is a precursor for: the aromatic amino acids phenylalanine and tyrosine; indole, indole derivatives and tryptophan; many alkaloids and other aromatic metabolites; tannins; and lignin. In pharmaceutical industry, shikimic acid from chinese star anise is used as a base material for production of Tamiflu (oseltamivir). Although shikimic acid is present in most autotrophic organisms, it is a biosynthetic intermediate and generally found in very low concentrations.
Sinapic acid, also known as sinapinate, belongs to the class of organic compounds known as hydroxycinnamic acids. Hydroxycinnamic acids are compounds containing an cinnamic acid where the benzene ring is hydroxylated. Sinapic acid has been detected, but not quantified, in several different foods, such as strawberry guava, purple lavers, common verbena, ryes, and lupines. This could make sinapic acid a potential biomarker for the consumption of these foods. A sinapic acid in which the double bond has trans-configuration.
Sorbitol is a polyhydric alcohol with about half the sweetness of sucrose. Sorbitol occurs naturally and is also produced synthetically from glucose. It was formerly used as a diuretic and may still be used as a laxative and in irrigating solutions for some surgical procedures. It is also used in many manufacturing processes, as a pharmaceutical aid, and in several research applications. Ascorbic acid fermentation; in solution form for moisture-conditioning of cosmetic creams and lotions, toothpaste, tobacco, gelatin; bodying agent for paper, textiles, and liquid pharmaceuticals; softener for candy; sugar crystallization inhibitor; surfactants; urethane resins and rigid foams; plasticizer, stabilizer for vinyl resins; food additive (sweetener, humectant, emulsifier, thickener, anticaking agent); dietary supplement. (Hawley's Condensed Chemical Dictionary) Biological Source: Occurs widely in plants ranging from algae to the higher orders. Fruits of the plant family Rosaceae, which include apples, pears, cherries, apricots, contain appreciable amounts. Rich sources are the fruits of the Sorbus and Crataegus species Use/Importance: Used for manufacturing of sorbose, propylene glycol, ascorbic acid, resins, plasticizers and as antifreeze mixtures with glycerol or glycol. Tablet diluent, sweetening agent and humectant, other food uses. Sorbitol is used in photometric determination of Ru(VI) and Ru(VIII); in acid-base titration of borate (Dictionary of Organic Compounds).
Sotalol is only found in individuals that have used or taken this drug. It is an adrenergic beta-antagonist that is used in the treatment of life-threatening arrhythmias (PubChem). Sotalol has both beta-adrenoreceptor blocking (Vaughan Williams Class I) and cardiac action potential duration prolongation (Vaughan Williams Class I) antiarrhythmic properties. Sotalol is a racemic mixture of d- and l-sotalol. Both isomers have similar Class I antiarrhythmic effects, while the l-isomer is responsible for virtually all of the beta-blocking activity. Sotalol inhibits response to adrenergic stimuli by competitively blocking &#946;<sub>1</sub>-adrenergic receptors within the myocardium and &#946;<sub>2</sub>-adrenergic receptors within bronchial and vascular smooth muscle. The electrophysiologic effects of sotalol may be due to its selective inhibition of the rapidly activating component of the potassium channel involved in the repolarization of cardiac cells. The class II electrophysiologic effects are caused by an increase in sinus cycle length (slowed heart rate), decreased AV nodal conduction, and increased AV nodal refractoriness, while the class III electrophysiological effects include prolongation of the atrial and ventricular monophasic action potentials, and effective refractory period prolongation of atrial muscle, ventricular muscle, and atrio-ventricular accessory pathways (where present) in both the anterograde and retrograde directions.
Stavudine is only found in individuals that have used or taken this drug. It is a dideoxynucleoside analog that inhibits reverse transcriptase and has in vitro activity against HIV. [PubChem]Stavudine inhibits the activity of HIV-1 reverse transcriptase (RT) both by competing with the natural substrate dGTP and by its incorporation into viral DNA.
Sucrose is a nonreducing disaccharide composed of glucose and fructose linked via their anomeric carbons. It is obtained commercially from sugarcane (Saccharum officinarum), sugar beet (Beta vulgaris), and other plants and used extensively as a food and a sweetener. Sucrose is derived by crushing and extracting sugarcane with water or by extracting sugar beet with water, evaporating, and purifying with lime, carbon, and various liquids. Sucrose is also obtainable from sorghum. Sucrose occurs in low percentages in honey and maple syrup. Sucrose is used as a sweetener in foods and soft drinks, in the manufacture of syrups, in invert sugar, confectionery, preserves and jams, demulcent, pharmaceutical products, and caramel. Sucrose is also a chemical intermediate for detergents, emulsifying agents, and other sucrose derivatives. Sucrose is widespread in the seeds, leaves, fruits, flowers, and roots of plants, where it functions as an energy store for metabolism and as a carbon source for biosynthesis. The annual world production of sucrose is in excess of 90 million tons mainly from the juice of sugar cane (20%) and sugar beet (17%). In addition to its use as a sweetener, sucrose is used in food products as a preservative, antioxidant, moisture control agent, stabilizer, and thickening agent. BioTransformer predicts that sucrose is a product of 6-O-sinapoyl sucrose metabolism via a hydrolysis-of-carboxylic-acid-ester-pattern1 reaction occurring in human gut microbiota and catalyzed by the liver carboxylesterase 1 (P23141) enzyme (PMID: 30612223).
Syringic acid, also known as syringate or cedar acid, belongs to the class of organic compounds known as gallic acid and derivatives. Gallic acid and derivatives are compounds containing a 3,4,5-trihydroxybenzoic acid moiety. Outside of the human body, Syringic acid is found, on average, in the highest concentration within a few different foods, such as common walnuts, swiss chards, and olives and in a lower concentration in apples, tarragons, and peanuts. Syringic acid has also been detected, but not quantified in several different foods, such as sweet marjorams, silver lindens, bulgurs, annual wild rices, and barley. This could make syringic acid a potential biomarker for the consumption of these foods. Syringic acid is correlated with high antioxidant activity and inhibition of LDL oxidation. Research suggests that phenolics from wine may play a positive role against oxidation of low-density lipoprotein (LDL), which is a key step in the development of atherosclerosis. Syringic acid is a phenol present in some distilled alcohol beverages. It is also a product of microbial (gut) metabolism of anthocyanins and other polyphenols that have been consumed (in fruits and alcoholic beverages - PMID:18767860). Syringic acid is also a microbial metabolite that can be found in Bifidobacterium (PMID:24958563).
Tacrolimus (also FK-506 or Fujimycin) is an immunosuppressive drug whose main use is after organ transplant to reduce the activity of the patient's immune system and so the risk of organ rejection. It is also used in a topical preparation in the treatment of severe atopic dermatitis, severe refractory uveitis after bone marrow transplants, and the skin condition vitiligo. It was discovered in 1984 from the fermentation broth of a Japanese soil sample that contained the bacteria Streptomyces tsukubaensis. Tacrolimus is chemically known as a macrolide. It reduces peptidyl-prolyl isomerase activity by binding to the immunophilin FKBP-12 (FK506 binding protein) creating a new complex. This FKBP12-FK506 complex interacts with and inhibits calcineurin thus inhibiting both T-lymphocyte signal transduction and IL-2 transcription.
Tadalafil is an orally adminstered drug used to treat male erectile dysfunction (impotence). It is marketed worldwide under the brand name Cialis. It is a phosphodiesterase 5 (PDE5) inhibitor. Tadalafil's distinguishing pharmacologic feature is its longer half-life (17.5 hours) compared with Viagra and Levitra (4-5 hours). This longer half-life results in a longer duration of action and is, in part, responsible for the Cialis nickname of the 'weekend pill.' This longer half-life also is the basis of current investigation for tadalafil's use in pulmonary arterial hypertension as a once-daily therapy. [Wikipedia]
3-carboxy-2,3-dihydroxypropanoate is classified as a sugar acid or a Sugar acid derivative. Sugar acids are compounds containing a saccharide unit which bears a carboxylic acid group. 3-carboxy-2,3-dihydroxypropanoate is considered to be soluble (in water) and acidic
Taurocholic acid is a bile acid and is the product of the conjugation of cholic acid with taurine. Its sodium salt is the chief ingredient of the bile of carnivorous animals. Bile acids are steroid acids found predominantly in the bile of mammals. The distinction between different bile acids is minute, depending only on the presence or absence of hydroxyl groups on positions 3, 7, and 12. Bile acids are physiological detergents that facilitate excretion, absorption, and transport of fats and sterols in the intestine and liver. Bile acids are also steroidal amphipathic molecules derived from the catabolism of cholesterol. They modulate bile flow and lipid secretion, are essential for the absorption of dietary fats and vitamins, and have been implicated in the regulation of all the key enzymes involved in cholesterol homeostasis. Bile acids recirculate through the liver, bile ducts, small intestine, and portal vein to form an enterohepatic circuit. They exist as anions at physiological pH, and consequently require a carrier for transport across the membranes of the enterohepatic tissues. The unique detergent properties of bile acids are essential for the digestion and intestinal absorption of hydrophobic nutrients. Bile acids have potent toxic properties (e.g. membrane disruption) and there are a plethora of mechanisms to limit their accumulation in blood and tissues (PMID: 11316487, 16037564, 12576301, 11907135). Taurocholic acid, as with all bile acids, acts as a detergent to solubilize fats for absorption and is itself absorbed. It is used as a cholagogue and choleretic (a bile purging agent). Hydrolysis of taurocholic acid yields taurine, a nonessential amino acid. Taurocholic acid is one of the main components of urinary nonsulfated bile acids in biliary atresia. Raised levels of taurocholate in fetal serum in obstetric cholestasis may result in the development of a fetal dysrhythmia and sudden intra-uterine death (PMID: 3944741, 11256973).
Telmisartan is an angiotensin II receptor antagonist (ARB) used in the management of hypertension. Generally, angiotensin II receptor blockers (ARBs) such as telmisartan bind to the angiotensin II type 1 (AT1) receptors with high affinity, causing inhibition of the action of angiotensin II on vascular smooth muscle, ultimately leading to a reduction in arterial blood pressure. Recent studies suggest that telmisartan may also have PPAR-gamma agonistic properties that could potentially confer beneficial metabolic effects.
L-Theanine, also known as L-gamma-glutamylethylamide or N-gamma-ethyl-L-glutamine, is a member of the class of compounds known as glutamine and derivatives. These compounds contain glutamine or a derivative thereof resulting from a reaction of glutamine at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom. L-Theanine is slightly soluble (in water) and a moderately acidic compound (based on its pKa). L-Theanine can be found in saliva. The regulatory status of theanine varies by country. In Japan, L-theanine has been approved for use in all foods, including herb teas, soft drinks, and desserts. Restrictions apply to infant foods. In the United States, the Food and Drug Administration (FDA) considers it to be generally recognized as safe (GRAS) and allows its sale as a dietary supplement. The German Federal Institute for Risk Assessment, an agency of their Federal Ministry of Food and Agriculture, objects to the addition of L-theanine to beverages. The European Food Safety Authority EFSA advised negatively on health claims related to L-theanine and cognitive function, alleviation of psychological stress, maintenance of normal sleep, and reduction of menstrual discomfort. Therefore, health claims for L-theanine are prohibited in the European Union (Wikipedia). L-Theanine is found in mushrooms and is a constituent of tea (Thea sinensis) and of the fungus Imleria badia. L-Theanine has been shown to exhibit neuroprotectant and neuroprotective functions (PMID: 20416364, 20416364).
Theophylline, also known as quibron TSR or uniphyl, belongs to the class of organic compounds known as xanthines. These are purine derivatives with a ketone group conjugated at carbons 2 and 6 of the purine moiety. Theophylline also binds to the adenosine A2B receptor and blocks adenosine mediated bronchoconstriction. Theophylline is a drug which is used for the treatment of the symptoms and reversible airflow obstruction associated with chronic asthma and other chronic lung diseases, such as emphysema and chronic bronchitis. Theophylline is marketed under several brand names such as Theophylline and Theochron, and it is indicated mainly for asthma, bronchospasm, and COPD. Within humans, theophylline participates in a number of enzymatic reactions. In particular, theophylline and formaldehyde can be biosynthesized from caffeine; which is mediated by the enzymes cytochrome P450 1A2, cytochrome P450 3A4, cytochrome P450 2C8, cytochrome P450 2C9, and cytochrome P450 2E1. In addition, theophylline can be converted into 1-methylxanthine and formaldehyde; which is mediated by the enzyme cytochrome P450 1A2. In humans, theophylline is involved in caffeine metabolism. Theophylline is a bitter tasting compound. Outside of the human body, Theophylline is found, on average, in the highest concentration within cocoa beans and tea. Theophylline has also been detected, but not quantified in a few different foods, such as arabica coffee, lemons, and pummelo. This could make theophylline a potential biomarker for the consumption of these foods. Theophylline is a potentially toxic compound.
Thymidine, also known as deoxythymidine or deoxyribosylthymine or thymine deoxyriboside, is a pyrimidine deoxynucleoside. It consists of the nucleobase thymine attached to deoxyribose through a beta N- glycosidic bond. Thymidine also belongs to the class of organic compounds known as pyrimidine 2'-deoxyribonucleosides. Pyrimidine 2'-deoxyribonucleosides are compounds consisting of a pyrimidine linked to a ribose which lacks a hydroxyl group at position 2. Deoxythymidine (or thymidine) is the DNA nucleoside T, which pairs with deoxyadenosine (A) in double-stranded DNA. Therefore, thymidine is essential to all life. Indeed, thymidine exists in all living species, ranging from bacteria to plants to humans. Within humans, thymidine participates in a number of enzymatic reactions. In particular, thymidine can be biosynthesized from 5-thymidylic acid through its interaction with the enzyme cytosolic purine 5'-nucleotidase. In addition, thymidine can be converted into 5-thymidylic acid; which is catalyzed by the enzyme thymidine kinase. Deoxythymidine can be phosphorylated with one, two or three phosphoric acid groups, creating dTMP (deoxythymidine monophosphate), dTDP, or dTTP (for the di- and tri- phosphates, respectively). dTMP can be incorporated into DNA via DNA polymerases. In cell biology, thymidine can be used to synchronize the cells in S phase. Derivatives of thymidine are used in a number of drugs, including Azidothymidine (AZT), which is used in the treatment of HIV infection. AZT inhibits the process of reverse transcription in the human immunodeficiency virus.
5-Thymidylic acid (conjugate base thymidylate), also known as thymidine monophosphate (TMP), deoxythymidine monophosphate (dTMP), or deoxythymidylic acid (conjugate base deoxythymidylate), is a nucleotide that is used as a monomer in DNA. It is an ester of phosphoric acid with the nucleoside thymidine. dTMP consists of a phosphate group, the pentose sugar deoxyribose, and the nucleobase thymine. Unlike the other deoxyribonucleotides, thymidine monophosphate often does not contain the "deoxy" prefix in its name; nevertheless, its symbol often includes a "d" ("dTMP"). 5-Thymidylic acid belongs to the class of organic compounds known as pyrimidine 2'-deoxyribonucleoside monophosphates. These are pyrimidine nucleotides with a monophosphate group linked to the ribose moiety lacking a hydroxyl group at position 2. The neutral species of 5-Thymidylic acid (2'-deoxythymidine 5'-monophosphate). 5-Thymidylic acid exists in all living species, ranging from bacteria to humans. Within humans, 5-thymidylic acid participates in a number of enzymatic reactions. In particular, 5-thymidylic acid and dihydrofolic acid can be biosynthesized from dUMP and 5,10-methylene-THF by the enzyme thymidylate synthase. In addition, 5-thymidylic acid can be converted into dTDP; which is catalyzed by the enzyme thymidylate synthase. In humans, 5-thymidylic acid is involved in pyrimidine metabolism. Outside of the human body, 5-Thymidylic acid has been detected, but not quantified in several different foods, such as common buckwheats, corn salad, garden cress, squashberries, and star fruits.
Tolterodine is only found in individuals that have used or taken this drug. It is an antimuscarinic drug that is used to treat urinary incontinence. Tolterodine acts on M2 and M3 subtypes of muscarinic receptors.Both tolterodine and its active metabolite, 5-hydroxymethyltolterodine, act as competitive antagonists at muscarinic receptors. This antagonism results in inhibition of bladder contraction, decrease in detrusor pressure, and an incomplete emptying of the bladder.
Topotecan is only found in individuals that have used or taken this drug. It is an antineoplastic agent used to treat ovarian cancer. It works by inhibiting DNA topoisomerases, type I. [PubChem]Topotecan has the same mechanism of action as irinotecan and is believed to exert its cytotoxic effects during the S-phase of DNA synthesis. Topoisomerase I relieves torsional strain in DNA by inducing reversible single strand breaks. Topotecan binds to the topoisomerase I-DNA complex and prevents religation of these single strand breaks. This ternary complex interferes with the moving replication fork, which leads to the induction of replication arrest and lethal double-stranded breaks in DNA. As mammalian cells cannot efficiently repair these double strand breaks, the formation of this ternary complex eventually leads to apoptosis (programmed cell death).Topotecan mimics a DNA base pair and binds at the site of DNA cleavage by intercalating between the upstream (âˆ’1) and downstream (+1) base pairs. Intercalation displaces the downstream DNA, thus preventing religation of the cleaved strand. By specifically binding to the enzymeâ€“substrate complex, Topotecan acts as an uncompetitive inhibitor.
Ketorolac is only found in individuals that have used or taken this drug. It is a pyrrolizine carboxylic acid derivative structurally related to indomethacin. It is an NSAID and is used principally for its analgesic activity (from Martindale The Extra Pharmacopoeia, 31st ed). Ketorolac is a nonsteroidal anti-inflammatory drug (NSAID) chemically related to indomethacin and tolmetin. Ketorolac tromethamine is a racemic mixture of [-]S- and [+]R-enantiomeric forms, with the S-form having analgesic activity. Its antiinflammatory effects are believed to be due to inhibition of both cylooxygenase-1 (COX-1) and cylooxygenase-2 (COX-2) which leads to the inhibition of prostaglandin synthesis leading to decreased formation of precursors of prostaglandins and thromboxanes from arachidonic acid. The resultant reduction in prostaglandin synthesis and activity may be at least partially responsible for many of the adverse, as well as the therapeutic, effects of these medications. Analgesia is probably produced via a peripheral action in which blockade of pain impulse generation results from decreased prostaglandin activity. However, inhibition of the synthesis or actions of other substances that sensitize pain receptors to mechanical or chemical stimulation may also contribute to the analgesic effect. In terms of the ophthalmic applications of ketorolac - ocular administration of ketorolac reduces prostaglandin E2 levels in aqueous humor, secondary to inhibition of prostaglandin biosynthesis.
Torasemide (rINN) or torsemide (USAN) is a pyridine-sulfonylurea type loop diuretic mainly used in the management of edema associated with congestive heart failure. It is also used at low doses for the management of hypertension. It is marketed under the brand name Demadex. [Wikipedia]
Trehalose 6-phosphate is a substrate for Hexokinase (type I) and Tryptase beta-1. Trehalose 6-phosphate has been found to be a microbial metabolite in Escherichia, Mycobacterium and Saccharomyces (UniProt).
Trehalose, also known as mycose, is a 1-alpha (disaccharide) sugar found extensively but not abundantly in nature. It is thought to be implicated in anhydrobiosis - the ability of plants and animals to withstand prolonged periods of desiccation. The sugar is thought to form a gel phase as cells dehydrate, which prevents disruption of internal cell organelles by effectively splinting them in position. Rehydration then allows normal cellular activity to be resumed without the major, generally lethal damage that would normally follow a dehydration/reyhdration cycle. Trehalose is a non-reducing sugar formed from two glucose units joined by a 1-1 alpha bond giving it the name of alpha-D-glucopyranoglucopyranosyl-1,1-alpha-D-glucopyranoside. The bonding makes trehalose very resistant to acid hydrolysis, and therefore stable in solution at high temperatures even under acidic conditions. The bonding also keeps non-reducing sugars in closed-ring form, such that the aldehyde or ketone end-groups do not bind to the lysine or arginine residues of proteins (a process called glycation). The enzyme trehalase, present but not abundant in most people, breaks it into two glucose molecules, which can then be readily absorbed in the gut. Trehalose is an important components of insects circulating fluid. It acts as a storage form of insect circulating fluid and it is important in respiration. Trehalose has also been found to be a metabolite of Burkholderia, Escherichia and Propionibacterium (PMID:12105274; PMID:25479689) (krishikosh.egranth.ac.in/bitstream/1/84382/1/88571%20P-1257.pdf).
Trichloroacetic acid (TCA; also known as trichloroethanoic acid) is an analogue of acetic acid in which the three hydrogen atoms of the methyl group have all been replaced by chlorine atoms.
N-carbamoylglutamic Acid, also known as N-Carbamoylglutamate, is classified as a glutamic acid or a Glutamic acid derivative. Glutamic acids are compounds containing glutamic acid or a derivative thereof resulting from reaction of glutamic acid at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom. N-carbamoylglutamic Acid is considered to be soluble (in water) and acidic
Uridine 5'-monophosphate (UMP), also known as uridylic acid or uridylate, belongs to the class of organic compounds known as pyrimidine ribonucleoside monophosphates. These are pyrimidine ribobucleotides with monophosphate group linked to the ribose moiety. UMP consists of a phosphate group, a pentose sugar ribose, and the nucleobase uracil; hence, it is a ribonucleotide monophosphate. Uridine 5'-monophosphate exists in all living species, ranging from bacteria to plants to humans. UMP is a nucleotide that is primarily used as a monomer in RNA biosynthesis. Uridine monophosphate is formed from Orotidine 5'-monophosphate (orotidylic acid) in a decarboxylation reaction catalyzed by the enzyme orotidylate decarboxylase. Within humans, uridine 5'-monophosphate participates in a number of enzymatic reactions. In particular, uridine 5'-monophosphate can be converted into uridine 5'-diphosphate through the action of the enzyme UMP-CMP kinase. In addition, uridine 5'-monophosphate can be biosynthesized from uridine 5'-diphosphate through its interaction with the enzyme soluble calcium-activated nucleotidase 1. In brain research studies, uridine monophosphate has been used as a convenient delivery compound for uridine.  Uridine is present in many foods, mainly in the form of RNA. Non-phosphorylated uridine is not bioavailable beyond first-pass metabolism. In a study, gerbils fed a combination of uridine monophosphate, choline, and docosahexaenoic acid (DHA) were found to have significantly improved performance in running mazes over those not fed the supplements, implying an increase in cognitive function (PMID: 18606862).
Uridine diphosphategalactose (UDPgal) is a nucleoside diphosphate sugar which can be epimerized into UDPglucose for entry into the mainstream of carbohydrate metabolism. UDPgal is a pivotal compound in the metabolism of galactose. UDPgal is a product of the galactose-l-phosphate uridyl transferase (EC 2.7.7.10) reaction but may also be made from Glucose-l-P, involving uridine diphosphate galactose-4-epimerase (EC 5.1.3.2). UDPgal is the necessary galactosyl donor of galactose in the metabolism to incorporate it into complex oligosaccharides, glycoproteins and glycolipids (galactosides). Defective galactosylation of complex glycoconjugates exists in tissues from galactosemic patients. There is a tendency for galactosemic red cell UDPgal to be in the low normal range with a high uridine diphosphate glucose to UDP-gal ratio. This may reflect an inability of red cell UDPgal-4'-epimerase to maintain a normal ratio and consequently higher levels of UDPgal. In the more complex white blood cells and cultured fibroblasts, the UDPgal content and the uridine diphosphate glucose to UDPgal ratio of galactosemics are normal. Therefore, defective galactosylation observed in galactosemic fibroblasts must result from a defect in the transfer of galactose from UDPgal to these moieties. (PMID: 2122114, 7671968).
Uridine diphosphate glucuronic acid is a nucleoside diphosphate sugar which serves as a source of glucuronic acid for polysaccharide biosynthesis. It may also be epimerized to UDP Iduronic acid, which donates Iduronic acid to polysaccharides. In animals, UDP glucuronic acid is used for formation of many glucosiduronides with various aglycones. The transfer of glucuronic acid from UDP-alpha-D-glucuronic acid onto a terminal galactose residue is done by beta1,3-glucuronosyltransferases, responsible for the completion of the protein-glycosaminoglycan linkage region of proteoglycans and of the HNK1 epitope of glycoproteins and glycolipids. In humans the enzyme galactose-beta-1,3-glucuronosyltransferase I completes the synthesis of the common linker region of glycosaminoglycans (GAGs) by transferring glucuronic acid (GlcA) onto the terminal galactose of the glycopeptide primer of proteoglycans. The GAG chains of proteoglycans regulate major biological processes such as cell proliferation and recognition, extracellular matrix deposition, and morphogenesis. (PMID:16815917).
This compound belongs to the family of Pyrimidine Nucleotide Sugars. These are pyrimidine nucleotides bound to a saccharide derivative through the terminal phosphate group.
Uridine diphosphate glucose, also known as UDP-glucose or UDP-alpha-D-glucose, belongs to the class of organic compounds known as pyrimidine nucleotide sugars. These are pyrimidine nucleotides bound to a saccharide derivative through the terminal phosphate group. Uridine diphosphate glucose exists in all living species, ranging from bacteria to plants to humans. Uridine diphosphate glucose is a key intermediate in carbohydrate metabolism. For instance, UDP-glucose is a precursor of glycogen and can be converted into UDP-galactose and UDP-glucuronic acid, which can then be used as substrates by the enzymes that make polysaccharides containing galactose and glucuronic acid. UDP-glucose can also be used as a precursor for the biosynthesis of sucrose, lipopolysaccharides and glycosphingolipids. Within humans, uridine diphosphate glucose participates in a number of enzymatic reactions. In particular, ceramide (D18:1/18:0) and uridine diphosphate glucose can be converted into glucosylceramide (D18:1/18:0) and uridine 5'-diphosphate through the action of the enzyme ceramide glucosyltransferase. In addition, glucosylceramide (D18:1/18:0) and uridine diphosphate glucose can be biosynthesized from lactosylceramide (D18:1/18:0) and uridine 5'-diphosphate through its interaction with the enzyme Beta-1,4-galactosyltransferase 6.
Urocanic acid (CAS: 104-98-3) is a breakdown (deamination) product of histidine. In the liver, urocanic acid is an intermediate in the conversion of histidine to glutamic acid, whereas, in the epidermis, it accumulates and may be both a UV protectant and an immunoregulator. Urocanic acid (UA) exists as a trans isomer (t-UA, approximately 30 mg/cm2) in the uppermost layer of the skin (stratum corneum). t-UA is formed as the cells of the second layer of the skin become metabolically inactive. During this process, proteins and membranes degrade, histidine is released, and histidase (histidine ammonia lyase) catalyzes the deamination of histidine to form t-UA. t-UA accumulates in the epidermis until removal by either the monthly skin renewal cycle or sweat. Upon absorption of UV light, the naturally occurring t-UA isomerizes to its cis form, c-UA. Because DNA lesions (e.g., pyrimidine dimers) in the lower epidermis can result from UV-B absorption, initial research proposed that t-UA acted as a natural sunscreen absorbing UV-B in the stratum corneum before the damaging rays could penetrate into lower epidermal zones. Researchers have found that c-UA also suppresses contact hypersensitivity and delayed hypersensitivity, reduces the Langerhans cell count in the epidermis, prolongs skin-graft survival time, and affects natural killer cell activity. (E)-Urocanic acid is found in mushrooms. It has been isolated from Coprinus atramentarius (common ink cap) and Phallus impudicus (common stinkhorn).
cis-11-Octadecenoic acid, also known as (Z)-octadec-11-enoic acid or asclepic acid, belongs to the class of organic compounds known as long-chain fatty acids. These are fatty acids with an aliphatic tail that contains between 13 and 21 carbon atoms. cis-11-Octadecenoic acid is a very hydrophobic molecule, practically insoluble in water, and relatively neutral.
Valaciclovir (INN) or valacyclovir (USAN) is an antiviral drug used in the management of herpes simplex and herpes zoster (shingles). It is a prodrug, being converted in vivo to aciclovir. It is marketed by GlaxoSmithKline under the trade name Valtrex or Zelitrex. [Wikipedia]
Valdecoxib is a prescription drug used in the treatment of osteoarthritis, rheumatoid arthritis, and painful menstruation and menstrual symptoms. It is classified as a nonsteroidal anti-inflammatory drug, or NSAID, and should not be taken by anyone allergic to these types of medications.
Valsartan is an angiotensin-receptor blocker (ARB) that may be used to treat a variety of cardiac conditions including hypertension, diabetic nephropathy and heart failure. Valsartan lowers blood pressure by antagonizing the renin-angiotensin-aldosterone system (RAAS); it competes with angiotensin II for binding to the type-1 angiotensin II receptor (AT1) subtype and prevents the blood pressure increasing effects of angiotensin II. Unlike angiotensin-converting enzyme (ACE) inhibitors, ARBs do not have the adverse effect of dry cough. Valsartan may be used to treat hypertension, isolated systolic hypertension, left ventricular hypertrophy and diabetic nephropathy. It may also be used as an alternative agent for the treatment of heart failure, systolic dysfunction, myocardial infarction and coronary artery disease.
Vanillic acid is a phenolic acid found in some forms of vanilla and many other plant extracts. It is a flavouring and scent agent that produces a pleasant, creamy odour. It is the intermediate product in the two-step bioconversion of ferulic acid to vanillin (J Biotechnol 1996;50(2-3):107-13). Vanillic acid, which is a chlorogenic acid, is an oxidized form of vanillin. It is also an intermediate in the production of vanillin from ferulic acid. Vanillic acid is a metabolic byproduct of caffeic acid and is often found in the urine of humans who have consumed coffee, chocolate, tea, and vanilla-flavoured confectionary. Vanillic acid selectively and specifically inhibits 5'nucleotidase activity (PMID: 16899266). Vanillic acid is a microbial metabolite found in Amycolatopsis, Delftia, and Pseudomonas (PMID: 11152072, 10543794, 11728709, 9579070).
Vanillin, also known as vanillaldehyde or lioxin, belongs to the class of organic compounds known as methoxyphenols. Methoxyphenols are compounds containing a methoxy group attached to the benzene ring of a phenol moiety. It is used by the food industry as well as ethylvanillin. Vanillin exists in all living species, ranging from bacteria to humans. Vanillin is a sweet, chocolate, and creamy tasting compound. Vanillin is found, on average, in the highest concentration within a few different foods, such as corns, ryes, and sherries and in a lower concentration in beers, rums, and oats. Vanillin has also been detected, but not quantified, in several different foods, such as gooseberries, other bread, brazil nuts, shea tree, and ohelo berries. This could make vanillin a potential biomarker for the consumption of these foods. Vanillin is a potentially toxic compound. Synthetic vanillin, instead of natural Vanillin extract, is sometimes used as a flavouring agent in foods, beverages, and pharmaceuticals. Vanillin is the primary component of the extract of the Vanillin bean. Because of the scarcity and expense of natural Vanillin extract, there has long been interest in the synthetic preparation of its predominant component. Artificial Vanillin flavoring is a solution of pure vanillin, usually of synthetic origin. Today, artificial vanillin is made from either guaiacol or from lignin, a constituent of wood which is a byproduct of the paper industry. The first commercial synthesis of vanillin began with the more readily available natural compound eugenol.
Vardenafil (Levitra) is an oral therapy for the treatment of erectile dysfunction. It is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5). Penile erection is a hemodynamic process initiated by the relaxation of smooth muscle in the corpus cavernosum and its associated arterioles. During sexual stimulation, nitric oxide is released from nerve endings and endothelial cells in the corpus cavernosum. Nitric oxide activates the enzyme guanylate cyclase resulting in increased synthesis of cyclic guanosine monophosphate (cGMP) in the smooth muscle cells of the corpus cavernosum. The cGMP in turn triggers smooth muscle relaxation, allowing increased blood flow into the penis, resulting in erection. The tissue concentration of cGMP is regulated by both the rates of synthesis and degradation via phosphodiesterases (PDEs). The most abundant PDE in the human corpus cavernosum is the cGMPspecific phosphodiesterase type 5 (PDE5); therefore, the inhibition of PDE5 enhances erectile function by increasing the amount of cGMP.
Vincristine is only found in individuals that have used or taken this drug. It is an antitumor alkaloid isolated from Vinca Rosea. (Merck, 11th ed.)The antitumor activity of Vincristine is thought to be due primarily to inhibition of mitosis at metaphase through its interaction with tubulin. Like other vinca alkaloids, Vincristine may also interfere with: 1) amino acid, cyclic AMP, and glutathione metabolism, 2) calmodulin-dependent Ca<sup>2+</sup>-transport ATPase activity, 3) cellular respiration, and 4) nucleic acid and lipid biosynthesis.
Vitexin, also known as apigenin 8-C-glucoside or 8-glycosylapigenin, belongs to the class of organic compounds known as flavonoid 8-C-glycosides. Flavonoid 8-C-glycosides are compounds containing a carbohydrate moiety which is C-glycosidically linked to 8-position of a 2-phenylchromen-4-one flavonoid backbone. Vitexin is also described as an apigenin flavone glucoside. Vitexin has been found in passion flower, chasteberry, bamboo leaves, millet and Hawthorn. Vitexin has shown a wide range of pharmacological effects, such as antioxidant, anti-cancer, anti-inflammatory, anti-hyperalgesic, and neuroprotective effects (PMID: 27693342). Vitexin has also been shown to directly inhibit thyroid peroxidase and potentially contributes to goiter (PMID: 1696490). It is sometimes called a goitrogen.
Voriconazole (Vfend, Pfizer) is a triazole antifungal medication used to treat serious fungal infections. It is used to treat invasive fungal infections that are generally seen in patients who are immunocompromised. These include invasive candidiasis, invasive aspergillosis, and emerging fungal infections.
Warfarin is an anticoagulant that acts by inhibiting the synthesis of vitamin K-dependent coagulation factors. Warfarin is indicated for the prophylaxis and/or treatment of venous thrombosis and its extension, pulmonary embolism, and atrial fibrillation with embolization. It is also used as an adjunct in the prophylaxis of systemic embolism after myocardial infarction. Warfarin is also used as a rodenticide.
Xanthosine, also known as xanthine riboside, belongs to the class of organic compounds known as purine nucleosides. Purine nucleosides are compounds comprising a purine base attached to a ribosyl or deoxyribosyl moiety. Xanthosine is a nucleoside derived from xanthine and ribose. Xanthosine exists in all living species, ranging from bacteria to plants to humans. In plants xanthosine is the biosynthetic precursor to 7-methylxanthosine which is produced by the action of the enzyme known as 7-methylxanthosine synthase. 7-Methylxanthosine in turn is the precursor to theobromine (the active alkaloid in chocolate), which in turn is the precursor to caffeine, the active alkaloid in coffee and tea. Within humans, xanthosine participates in a number of enzymatic reactions. In particular, xanthosine can be biosynthesized from xanthylic acid; which is catalyzed by the enzyme cytosolic purine 5'-nucleotidase. In addition, xanthosine can be converted into xanthine and ribose 1-phosphate; which is mediated by the enzyme purine nucleoside phosphorylase. Xanthosine monophosphate (XMP) is an intermediate in purine metabolism, formed from IMP (inosine monophosphate).
Zafirlukast is an oral leukotriene receptor antagonist (LTRA) for the maintenance treatment of asthma, often used in conjunction with an inhaled steroid and/or long-acting bronchodilator. It is available as a tablet and is usually dosed twice daily. Another leukotriene receptor antagonist is montelukast (Singulair), which is usually taken just once daily. Zafirlukast blocks the action of the cysteinyl leukotrienes on the CysLT1 receptors, thus reducing constriction of the airways, build-up of mucus in the lungs and inflammation of the breathing passages.
Leukotrienes are substances that induce numerous biological effects including augmentation of neutrophil and eosinophil migration, neutrophil and monocyte aggregation, leukocyte adhesion, increased capillary permeability, and smooth muscle contraction. These effects contribute to inflammation, edema, mucus secretion, and bronchoconstriction in the airways of asthmatic patients. Zileuton relieves such symptoms through its selective inhibition of 5-lipoxygenase, the enzyme that catalyzes the formation of leukotrienes from arachidonic acid. Specifically, it inhibits leukotriene LTB4, LTC4, LTD4, and LTE4 formation. Both the R(+) and S(-) enantiomers are pharmacologically active as 5-lipoxygenase inhibitors in in vitro systems.
xi-2,3-Dihydro-2-oxo-1H-indole-3-acetic acid is found in brassicas. xi-2,3-Dihydro-2-oxo-1H-indole-3-acetic acid is isolated from Ribes rubrum (currant), Brassica species and Helianthus annuus (sunflower). xi-2,3-Dihydro-2-oxo-1H-indole-3-acetic acid is a product of catabolism of 1H-Indole-3-acetic acid <ht>BNC14-M</ht> in Zea mays (sweetcorn
Estrone is a major mammalian estrogen. The conversion of the natural C19 steroids, testosterone and androstenedione into estrone is dependent on a complex key reaction catalyzed by the cytochrome P450 aromatase (EC 1.14.14.1, unspecific monooxygenase), which is expressed in many tissues of the adult human (e.g. ovary, fat tissue), but not in the liver. The ovaries after menopause continue to produce androstenedione and testosterone in significant amounts and these androgens are converted in fat, muscle, and skin into estrone. When women between the ages of 45 and 64 years have prophylactic oophorectomy (when hysterectomy is performed for benign disease to prevent the development of ovarian cancer), evidence suggests that oophorectomy increases the subsequent risk of coronary heart disease (CHD) and osteoporosis. Whereas 14,000 women die of ovarian cancer every year nearly 490,000 women die of heart disease and 48,000 women die within 1 year after hip fracture. Therefore, the decision to perform prophylactic oophorectomy should be approached with great caution for the majority of women who are at low risk of developing ovarian cancer. Steroid sulfatase (EC 3.1.6.2, STS) hydrolyzes steroid sulfates, such as estrone sulfate to estrone which can be converted to steroids with potent estrogenic properties, that is, estradiol; STS activity is much higher in breast tumors and high levels of STS mRNA expression in tumors are associated with a poor prognosis. The biological roles of estrogens in tumorigenesis are certainly different between the endometrium and breast, although both are considered "estrogen-dependent tissues". 17beta-hydroxysteroid dehydrogenases (EC 1.1.1.62, 17-HSDs) are enzymes involved in the formation of active sex steroids. estrone is interconverted by two enzymes 17-HSD types. Type 1 converts estrone to estradiol and Type 2 catalyzes the reverse reaction. (PMID: 17653961, 17513923, 17470679, 17464097).
1,3,7-Trimethyluric acid is a methyl derivative of uric acid, found occasionally in human urine. 1,3,7-Trimethyluracil is one of the purine components in urinary calculi. Methylated purines originate from the metabolism of methylxanthines (caffeine, theophylline and theobromine). Methyluric acids are indistinguishable from uric acid by simple methods routinely used in clinical laboratories, requiring the use of high-performance liquid chromatography (HPLC). Purine derivatives in urinary calculi could be considered markers of abnormal purine metabolism. The content of a purine derivative in stone depends on its average urinary excretion in the general population, similarity to the chemical structure of uric acid, and content of the latter in stone. This suggests that purines in stones represent a solid solution with uric acid as solvent. It is also plausible that methylxanthines, ubiquitous components of the diet and drugs, are involved in the pathogenesis of urolithiasis. Caffeine is metabolized via successive pathways mainly catalyzed by CYP1A2, xanthine oxidase or N-acetyltransferase-2 to give 14 different metabolites. CYP1A2 activity shows an inter-individual variability among the population. CYP1A2, an isoform of the CYP1A cytochrome P450 super-family, is involved in the metabolism of many drugs and plays a potentially important role in the induction of chemical carcinogenesis. (PMID:11712316, 15833286, 3506820, 15013152).
1,7-Dimethyluric acid is the major urinary caffeine metabolite that is produced in the human body. 1,7-Dimethyluric acid is formed during caffeine metabolism and the process is catalyzed primarily by CYP2A6 (PMID: 18715882).
Paraxanthine, also known as p-xanthine, belongs to the class of organic compounds known as xanthines. These are purine derivatives with a ketone group conjugated at carbons 2 and 6 of the purine moiety. Paraxanthine exists in all living organisms, ranging from bacteria to humans. Within humans, paraxanthine participates in a number of enzymatic reactions. In particular, paraxanthine and formaldehyde can be biosynthesized from caffeine; which is catalyzed by the enzyme cytochrome P450 1A2. In addition, paraxanthine and acetyl-CoA can be converted into 5-acetylamino-6-formylamino-3-methyluracil through its interaction with the enzyme arylamine N-acetyltransferase 2. In humans, paraxanthine is involved in caffeine metabolism.
1-Methyladenosine, also known as M1A, belongs to the class of organic compounds known as purine nucleosides. Purine nucleosides are compounds comprising a purine base attached to a ribosyl or deoxyribosyl moiety. Precise m6A mapping by m6A-CLIP/IP (briefly m6A-CLIP) revealed that a majority of m6A locates in the last exon of mRNAs in multiple tissues/cultured cells of mouse and human, and the m6A enrichment around stop codons is a coincidence that many stop codons locate round the start of last exons where m6A is truly enriched. The methylation of adenosine is directed by a large m6A methyltransferase complex containing METTL3 as the SAM-binding sub-unit. Insulin-like growth factor-2 mRNA-binding proteins 1, 2, and 3 (IGF2BP1-3) are reported as a novel class of m6A readers.
1-Methylguanosine is a methylated nucleoside. It is known that some modified, especially methylated, nucleosides originating from RNA degradation are excreted in abnormal levels in the urine of patients with malignant tumours. These nucleosides have been proposed as tumour markers. Their measurement could provide a non-invasive diagnostic method, help identify different cancers, and monitor any therapeutic effects (PMID:9129323).
1-Methylnicotinamide is a metabolite of nicotinamide and is produced primarily in the liver. It has anti-inflammatory properties (PMID 16197374). It is a product of nicotinamide N-methyltransferase [EC 2.1.1.1] in the pathway of nicotinate and nicotinamide metabolism (KEGG). 1-Methylnicotinamide may be an endogenous activator of prostacyclin production and thus may regulate thrombotic as well as inflammatory processes in the cardiovascular system (PMID: 17641676).
1-Methyluric acid is one of the three main theophylline metabolites in man. 1-Methyluric acid is one of the purine components in urinary calculi. Methylated purines originate from the metabolism of methylxanthines (caffeine, theophylline, and theobromine). Methyluric acids can be distinguished from uric acid via simple methods routinely used in clinical laboratories, requiring the use of high-performance liquid chromatography (HPLC). Purine derivatives in urinary calculi could be considered markers of abnormal purine metabolism. The content of a purine derivative in stone depends on its average urinary excretion in the general population, similarity to the chemical structure of uric acid, and content of the latter in stone. This suggests that purines in stones represent a solid solution with uric acid as solvent. It is also plausible that methylxanthines, ubiquitous components of the diet and drugs, are involved in the pathogenesis of urolithiasis. Caffeine is metabolized via successive pathways mainly catalyzed by CYP1A2, xanthine oxidase, or N-acetyltransferase-2 to give 14 different metabolites. CYP1A2 activity shows an inter-individual variability among the population. CYP1A2, an isoform of the CYP1A cytochrome P450 superfamily, is involved in the metabolism of many drugs and plays a potentially important role in the induction of chemical carcinogenesis (PMID:11712316, 15833286, 3506820, 15013152, 4039734, 9890610).
Estriol-16-glucuronide is a glucuronide derivative of the steroid estriol where the glucuronic acid is attached to the 16-hydroxyl group of Estriol. Glucuronidation is used to assist in the excretion of toxic substances, drugs or other substances that cannot be used as an energy source. Glucuronic acid is attached via a glycosidic bond to the substance, and the resulting glucuronide, which has a much higher water solubility than the original substance, is eventually excreted by the kidneys. Estriol (also known as oestriol) is one of the three main estrogens produced by the human body. It is only produced in significant amounts during pregnancy as it is made by the placenta.
A dideoxynucleoside compound in which the 3'-hydroxyl group on the sugar moiety has been replaced by a hydrogen. This modification prevents the formation of 5' to 3' phosphodiester linkages, which are needed for the elongation of DNA chains, thus resulting in the termination of viral DNA growth. The compound is a potent inhibitor of HIV replication at low concentrations, acting as a chain-terminator of viral DNA by binding to reverse transcriptase. Its principal toxic side effect is axonal degeneration resulting in peripheral neuropathy. [PubChem]
A dideoxynucleoside compound in which the 3&#39;-hydroxy group on the sugar moiety has been replaced by a hydrogen. This modification prevents the formation of phosphodiester linkages which are needed for the completion of nucleic acid chains. Didanosine is a potent inhibitor of HIV replication, acting as a chain-terminator of viral DNA by binding to reverse transcriptase; ddI is then metabolized to dideoxyadenosine triphosphate, its putative active metabolite. [PubChem]
Deoxyadenosine is a derivative of the nucleoside adenosine. It is composed of adenine attached to a deoxyribose moiety via a N9-glycosidic bond. Deoxyribose differs from ribose by the absence of oxygen in the 3' position of its ribose ring. Deoxyadenosine is a critical component of DNA. When present in sufficiently high levels, deoxyadensoine can act as an immunotoxin and a metabotoxin. An immunotoxin disrupts, limits the function, or destroys immune cells. A metabotoxin is an endogenous metabolite that causes adverse health effects at chronically high levels. Chronically high levels of deoxyadenosine are associated with adenosine deaminase (ADA) deficiency, an inborn error of metabolism. ADA deficiency damages the immune system and causes severe combined immunodeficiency (SCID). People with SCID lack virtually all immune protection from bacteria, viruses, and fungi. They are prone to repeated and persistent infections that can be very serious or life-threatening. These infections are often caused by "opportunistic" organisms that ordinarily do not cause illness in people with a normal immune system. The main symptoms of ADA deficiency are pneumonia, chronic diarrhea, and widespread skin rashes. The mechanism by which dATP functions as an immunotoxin is as follows: because deoxyadenosine is a precursor to dATP, a buildup of dATP in cells inhibits ribonucleotide reductase and prevents DNA synthesis, so cells are unable to divide. Since developing T cells and B cells are some of the most mitotically active cells, they are unable to divide and propagate to respond to immune challenges. High levels of deoxyadenosine also lead to an increase in S-adenosylhomocysteine, which is toxic to immature lymphocytes.
Deoxyguanosine, also known as dG, belongs to the class of organic compounds known as purine 2'-deoxyribonucleosides. Purine 2'-deoxyribonucleosides are compounds consisting of a purine linked to a ribose which lacks a hydroxyl group at position 2‚Äô. Deoxyguanosine is a nucleoside consisting of the base guanine and the sugar deoxyribose. Deoxyguanosine is one of the four deoxyribonucleosides that make up DNA. Deoxyguanosine exists in all living species, ranging from bacteria to plants to humans. Deoxyguanosine participates in a number of enzymatic reactions. In particular, deoxyguanosine can be biosynthesized from 2'-deoxyguanosine 5'-monophosphate through the enzyme known as cytosolic purine 5'-nucleotidase. In addition, deoxyguanosine can be converted into 2'-deoxyguanosine 5'-monophosphate (dGMP); which is mediated by the enzyme deoxyguanosine kinase. Deoxyguanosine is involved in the rare, inherited metabolic disorder called the purine nucleoside phosphorylase deficiency (PNP deficiency). In particular PNP deficiency is characterized by elevated levels of dGTP (deoxyguanosine triphosphate). PNP accounts for approximately 4% of patients with severe combined immunodeficiency (PMID: 1931007). PNP-deficient patients suffer from recurrent infections, usually beginning in the first year of life. Two thirds of patients have evidence of neurologic disorders with spasticity, developmental delay and mental retardation. Deoxyguanosine can be converted to 8-hydroxy-deoxyguanosine (8-OHdG) due to hydroxyl radical attack at the C8 of guanine. 8-hydroxy-deoxyguanosine is a sensitive marker of the DNA damage This damage, if left unrepaired, has been proposed to contribute to mutagenicity and cancer promotion.
Deoxyuridine, also known as dU, belongs to the class of organic compounds known as pyrimidine 2'-deoxyribonucleosides. Pyrimidine 2'-deoxyribonucleosides are compounds consisting of a pyrimidine linked to a ribose which lacks a hydroxyl group at position 2. It is similar in chemical structure to uridine, but without the 2'-hydroxyl group. Deoxyuridine exists in all living organisms, ranging from bacteria to humans. Within humans, deoxyuridine participates in a number of enzymatic reactions. In particular, deoxyuridine can be biosynthesized from deoxycytidine through its interaction with the enzyme cytidine deaminase. In addition, deoxyuridine can be converted into uracil and deoxyribose 1-phosphate through its interaction with the enzyme thymidine phosphorylase. Deoxyuridine is considered to be an antimetabolite that is converted into deoxyuridine triphosphate during DNA synthesis. Laboratory suppression of deoxyuridine is used to diagnose megaloblastic anemia due to vitamin B12 and folate deficiencies. In humans, deoxyuridine is involved in the metabolic disorder called UMP synthase deficiency (orotic aciduria). Outside of the human body, deoxyuridine has been detected, but not quantified in, several different foods, such as lichee, highbush blueberries, agaves, macadamia nut (M. tetraphylla), and red bell peppers. This could make deoxyuridine a potential biomarker for the consumption of these foods.
2'-O-Methyluridine belongs to the class of organic compounds known as pyrimidine nucleosides. Pyrimidine nucleosides are compounds comprising a pyrimidine base attached to a ribosyl or deoxyribosyl moiety. 2'-O-Methyluridine was identified as one of forty plasma metabolites that could be used to predict gut microbiome Shannon diversity (PMID: 31477923). Shannon diversity is a metric that summarizes both species abundance and evenness, and it has been suggested as a marker for microbiome health.
2,3-Butanediol is an isomer of butanediol. The 2R,3R stereoisomer of 2,3-butanediol is produced by a variety of microorganisms, in a process known as butanediol fermentation. 2,3-Butanediol fermentation is the anaerobic fermentation of glucose with 2,3-butanediol as one of the end products. The overall stoichiometry of the reaction is 2 pyruvate + NADH --> 2CO2 + 2,3-butanediol. Butanediol fermentation is typical for Enterobacter species or microbes found in the gut. 2,3-butanediol has been identified in the sera of alcoholics and it may be a specific marker of alcohol abuse (PMID:6139706). In humans, 2,3-butanediol is oxidized to acetyl-CoA via acetoin. 2,3-Butanediol is also found in cocoa butter. 2,3-Butanediol can also be found in Bacillus, Klebsiella and Serratia (PMID:21272631).
2,8-Quinolinediol, also known as quinoline-2,8-diol or 8-hydroxycarbostyril, belongs to the class of organic compounds known as quinolones and derivatives. Quinolones and derivatives are compounds containing a quinoline moiety that bears a ketone group. 2,8-Quinolinediol has been identified in urine (PMID: 30089834).
This compound belongs to the family of M-methoxybenzoic Acids and Derivatives. These are benzoic acids  in which the hydrogen atom at position 3 of the benzene ring is replaced by a methoxy group
2-Aminoacetophenone is found in cereals and cereal products. 2-Aminoacetophenone is a component of tortilla aroma and of other corn flour product
Cysteamine is a product of the constitutive degradation of coenzyme A, a process that occurs in all tissues, although some tissues such as brain and heart may have exceptionally high coenzyme A turnover rates. Cysteamine has only one known function, and that is as a precursor for the formation of hypotaurine, which is subsequently oxidized to taurine. The rate of cysteamine production as a result of coenzyme A breakdown is not well understood but it is clear that cysteamine levels are not as dramatically affected by dietary habits as are cysteine levels. Cysteamine is generated from hypotaurine by cysteamine dioxygenase (EC:1.13.11.19), an enzyme that was recently identified in mammals (PMID:17581819). Cysteamine is the simplest stable aminothiol found in the body. It is used in the treatment of disorders of cystine excretion. Cysteamine cleaves the disulfide bond with cysteine to produce molecules that can escape the metabolic defect in cystinosis and cystinuria. Cyst(e)amine may also serve as an endogenous regulator of immune system activity as well as a potential therapeutic agent for the treatment of Huntington disease. Cysteamine is also used as a radiation-protective agent that oxidizes in air to form cystamine. It can be given intravenously or orally to treat radiation sickness.
Deoxyadenosine monophosphate (dAMP), also known as deoxyadenylic acid or deoxyadenylate in its conjugate acid and conjugate base forms, respectively, is a derivative of the common nucleic acid AMP, or adenosine monophosphate, in which the -OH (hydroxyl) group on the 2' carbon on the nucleotide's pentose has been reduced to just a hydrogen atom (hence the "deoxy-" part of the name). Additionally, the monophosphate of the name indicates that two of the phosphoryl groups of GTP have been removed, most likely by hydrolysis. It is a monomer used in DNA.
2-Hydroxy-3-methylbutyric acid (also known as 2-hydroxyisovaleric acid) is a metabolite found in the urine of patients with phenylketonuria (PMID: 7978272), methylmalonic acidemia, propionic acidemia, 3-ketothiolase deficiency, isovaleric acidemia, 3-methylcrotonylglycemia, 3-hydroxy-3-methylglutaric acidemia, multiple carboxylase deficiency, glutaric aciduria, ornithine transcarbamylase deficiency, glyceroluria, tyrosinemia type I, galactosemia, and maple syrup urine disease (PMID: 11048741). 2-Hydroxyisovaleric acid has also been identified in the urine of patients with lactic acidosis and ketoacidosis (PMID: 884872), and in the urine of severely asphyxiated babies (PMID: 1610944). 2-Hydroxyisovaleric acid originates mainly from ketogenesis and from the metabolism of valine, leucine, and isoleucine (PMID: 6434570). 2-Hydroxy-3-methylbutyric acid has been identified in the human placenta (PMID: 32033212).
Leucinic acid, also known as leucic acid, 2-hydroxyisocaproic acid or 2-hydroxy-4-methylvaleric acid, belongs to the class of organic compounds known as hydroxy fatty acids. These are fatty acids in which the chain bears a hydroxyl group. Leucinic acid is a valeric acid derivative having a hydroxy substituent at the 2-position and a methyl substituent at the 4-position. It is an alpha-hydroxy analogue of leucine and a metabolite of the branched-chain amino acid leucine. Leucinic acid is found in all organisms ranging from bacteria to plants to animals. Leucinic acid has been found in a patient with dihydrolipoyl dehydrogenase (DLD) deficiency (PMID: 6688766). DLD deficiency is caused by mutations in the DLD gene and is inherited in an autosomal recessive manner. A common feature of dihydrolipoamide dehydrogenase deficiency is a potentially life-threatening buildup of lactic acid in tissues (lactic acidosis), which can cause nausea, vomiting, severe breathing problems, and an abnormal heartbeat. Neurological problems are also common in this condition; the first symptoms in affected infants are often decreased muscle tone (hypotonia) and extreme tiredness (lethargy). As the problems worsen, affected infants can have difficulty feeding, decreased alertness, and seizures. Liver problems can also occur in dihydrolipoamide dehydrogenase deficiency, ranging from an enlarged liver (hepatomegaly) to life-threatening liver failure. In some affected people, liver disease, which can begin anytime from infancy to adulthood, is the primary symptom. Leucinic acid is also present in the urine of patients with short bowel syndrome (PMID: 4018104)
2-Methoxy-4-vinylphenol is an aromatic substance used as a flavoring agent. It is one of the compounds responsible for the natural aroma of buckwheat.
MG(0:0/14:0/0:0) is a monoacylglyceride. A monoglyceride, more correctly known as a monoacylglycerol, is a glyceride consisting of one fatty acid chain covalently bonded to a glycerol molecule through an ester linkage. Monoacylglycerol can be broadly divided into two groups; 1-monoacylglycerols (or 3-monoacylglycerols) and 2-monoacylglycerols, depending on the position of the ester bond on the glycerol moiety. Normally the 1-/3-isomers are not distinguished from each other and are termed 'alpha-monoacylglycerols', while the 2-isomers are beta-monoacylglycerols. Monoacylglycerols are formed biochemically via release of a fatty acid from diacylglycerol by diacylglycerol lipase or hormone sensitive lipase. Monoacylglycerols are broken down by monoacylglycerol lipase. They tend to be minor components only of most plant and animal tissues, and indeed would not be expected to accumulate because their strong detergent properties would have a disruptive effect on membranes. 2-Monoacylglycerols are a major end product of the intestinal digestion of dietary fats in animals via the enzyme pancreatic lipase. They are taken up directly by the intestinal cells and converted to triacylglycerols via the monoacylglycerol pathway before being transported in lymph to the liver. Mono- and Diglycerides are commonly added to commercial food products in small quantities. They act as emulsifiers, helping to mix ingredients such as oil and water that would not otherwise blend well.
MG(0:0/16:0/0:0) is a monoacylglyceride. A monoglyceride, more correctly known as a monoacylglycerol, is a glyceride consisting of one fatty acid chain covalently bonded to a glycerol molecule through an ester linkage. Monoacylglycerol can be broadly divided into two groups; 1-monoacylglycerols (or 3-monoacylglycerols) and 2-monoacylglycerols, depending on the position of the ester bond on the glycerol moiety. Normally the 1-/3-isomers are not distinguished from each other and are termed 'alpha-monoacylglycerols', while the 2-isomers are beta-monoacylglycerols. Monoacylglycerols are formed biochemically via release of a fatty acid from diacylglycerol by diacylglycerol lipase or hormone sensitive lipase. Monoacylglycerols are broken down by monoacylglycerol lipase. They tend to be minor components only of most plant and animal tissues, and indeed would not be expected to accumulate because their strong detergent properties would have a disruptive effect on membranes. 2-Monoacylglycerols are a major end product of the intestinal digestion of dietary fats in animals via the enzyme pancreatic lipase. They are taken up directly by the intestinal cells and converted to triacylglycerols via the monoacylglycerol pathway before being transported in lymph to the liver. Mono- and Diglycerides are commonly added to commercial food products in small quantities. They act as emulsifiers, helping to mix ingredients such as oil and water that would not otherwise blend well.
2-Phenylacetamide is an intermediate in phenylalanine metabolism and styrene degradation(KEGG ID C02505). It is the third to last step in the synthesis of phenylacetylglutamine and is converted from phenylalanine via the enzyme phenylalanine 2-monooxygenase [EC:1.13.12.9]. It is then converted to phenylacetate via the enzyme amidase [EC:3.5.1.4].
Propionylglycine is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acyl glycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13) which is an enzyme that catalyzes the chemical reaction:acyl-CoA + glycine < -- > CoA + N-acylglycineThe level of propionylglycine is elevated in patients with propionic acidemia, which is an inherited deficiency of propionyl-CoA carboxylase. (Disorders of propionate and methylmalonate metabolism. In The Metabolic and Molecular Bases of Inherited Disease).
This colourless crystalline solid is used in peptide synthesis. It is well known to form hydrogen bonded structures somewhat related to the base-pairing mechanism found in RNA and DNA. It is also a classic case of a molecule that exists as tautomers. Some publications only focus one of the two possible patterns, and neglect the influence of the other. For example, to calculation of the energy difference of the two tautomers in a non-polar solution will lead to a wrong result if a large quantity of the substance is on the side of the dimer in an equilibrium. The direct tautomerisation is not energetically favoured, but a dimerisation followed by a double proton transfer and dissociation of the dimer is a self catalytic path from one tautomer to the other. Protic solvents also mediate the proton transfer during the tautomerisation.
3,4-Dimethoxybenzaldehyde is found in fruits. 3,4-Dimethoxybenzaldehyde is isolated from peppermint, raspberry, ginger and Bourbon vanilla. 3,4-Dimethoxybenzaldehyde is used in vanilla flavour
The use of tyrosine kinase receptor inhibitors is increasingly becoming a valuable therapeutic alternative in tumors carrying activated tyrosine kinase receptors. GMR beta tyrosine residues are not necessary for activation of the JAK/STAT pathway, or for proliferation, viability, or adhesion signaling in Ba/F3 cells, although tyrosine residues significantly affect the magnitude of the response. (PMID:10372132).
3-Aminoisobutanoic acid, also known as b-aminoisobutyrate or 2-methyl-beta-alanine, belongs to the class of organic compounds known as beta amino acids and derivatives. These are amino acids having a (-NH2) group attached to the beta carbon atom. 3-Aminoisobutanoic acid is a very hydrophobic molecule, practically insoluble in water, and relatively neutral. 3-Aminoisobutanoic acid exists in all eukaryotes, ranging from yeast to humans. 3-aminoisobutanoic acid can be biosynthesized from ureidoisobutyric acid; which is mediated by the enzyme Beta-ureidopropionase. In humans, 3-aminoisobutanoic acid is involved in the metabolic disorder called the beta-ureidopropionase deficiency pathway. Beta-ureidopropionase deficiency is an inborn error of pyrimidine degradation associated with neurological abnormalities (OMIM 606673). 3-Aminoisobutanoic acid is a potentially toxic compound.
Beta-Guanidinopropionic acid is analog of creatine and is reported to decrease phosphocreatine and ATP content in animal tissues in vivo.
3-Hydroxyanthranilic acid, also known as 2-amino-3-hydroxy-benzoate or 3-ohaa, belongs to the class of organic compounds known as hydroxybenzoic acid derivatives. Hydroxybenzoic acid derivatives are compounds containing a hydroxybenzoic acid (or a derivative), which is a benzene ring bearing a carboxyl and a hydroxyl groups. 3-Hydroxyanthranilic acid is a drug. 3-Hydroxyanthranilic acid exists in all living species, ranging from bacteria to humans. Within humans, 3-hydroxyanthranilic acid participates in a number of enzymatic reactions. In particular, 3-hydroxyanthranilic acid and L-alanine can be biosynthesized from L-3-hydroxykynurenine through the action of the enzyme kynureninase. In addition, 3-hydroxyanthranilic acid can be converted into cinnavalininate through the action of the enzyme catalase. 3-Hydroxyanthranilic acid is an intermediate in the metabolism of tryptophan. In humans, 3-hydroxyanthranilic acid is involved in tryptophan metabolism. Outside of the human body, 3-hydroxyanthranilic acid has been detected, but not quantified in brassicas. This could make 3-hydroxyanthranilic acid a potential biomarker for the consumption of these foods. It is new antioxidant isolated from methanol extract of tempeh. It is effective in preventing autoxidation of soybean oil and powder, while antioxidant 6,7,4'-trihydroxyisoflavone is not.
3-Hydroxyphenylacetic acid is a rutin metabolite and an antioxidant. It has a protective biological activity in human. It is a substrate of enzyme 4-hydroxyphenylacetate 3-monooxygenase [EC 1.14.13.3] in the pathway tyrosine metabolism (KEGG, PMID 155437). 3-Hydroxyphenylacetic acid is found to be associated with phenylketonuria, which is an inborn error of metabolism. It is also a marker of gut Clostridium species. Higher levels are associated with higher levels of Clostridia (PMID: 27123458). 3-Hydroxyphenylacetic acid can also be found in Klebsiella (PMID: 1851804).
3-Hydroxyvaleric acid may be products of the condensation of propionyl-CoA with acetyl-CoA catalyzed by 3-oxoacyl-CoA thiolases. An increase amount of 3-hydroxyvaleric acid can be found in methylmalonic acidemia and propionic acidemia. (PMID: 630060).
Indoleacetic acid (IAA) is a breakdown product of tryptophan metabolism and is often produced by the action of bacteria in the mammalian gut. Higher levels of IAA are associated with bacteria from Clostridium species including C. stricklandii, C. lituseburense, C. subterminale, and C. putrefaciens (PMID: 12173102). IAA can be found in Agrobacterium, Azospirillum, Bacillus, Bradyrhizobium, Clostridium, Enterobacter, Pantoea, Pseudomonas, Rhizobium (PMID: 12173102, PMID: 17555270, PMID: 12147474, PMID: 19400643, PMID: 9450337, PMID: 21397014) (https://link.springer.com/chapter/10.1007/978-1-4612-3084-7_7) (https://escholarship.org/uc/item/1bf1b5m3). Some endogenous production of IAA in mammalian tissues also occurs. It may be produced by the decarboxylation of tryptamine or the oxidative deamination of tryptophan. IAA frequently occurs at low levels in urine and has been found in elevated levels in the urine of patients with phenylketonuria (PMID: 13610897). IAA has also been identified as a uremic toxin according to the European Uremic Toxin Working Group (PMID: 22626821). Using material extracted from human urine, it was discovered by Kogl in 1933 that indoleacetic acid is also an important plant hormone (PMID: 13610897). Specifically, IAA is a member of the group of phytohormones called auxins. IAA is generally considered to be the most important native auxin. Plant cells synthesize IAA from tryptophan (Wikipedia). IAA and some derivatives can be oxidized by horseradish peroxidase (HRP) into cytotoxic species. IAA is only toxic after oxidative decarboxylation; the effect of IAA/HRP is thought to be due in part to the formation of methylene-oxindole, which may conjugate with DNA bases and protein thiols. IAA/HRP could be used as the basis for targeted cancer, a potential new role for plant auxins in cancer therapy (PMID: 11163327).
3-Indoleacetonitrile is a phytoalexin. Phytoalexins are antibiotics produced by plants that are under attack. Phytoalexins tend to fall into several classes including terpenoids, glycosteroids, and alkaloids; however, researchers often find it convenient to extend the definition to include all phytochemicals that are part of the plant's defensive arsenal. Phytoalexins produced in plants act as toxins to the attacking organism. They may puncture the cell wall, delay maturation, disrupt metabolism, or prevent the reproduction of the pathogen in question. However, phytoalexins are often targeted to specific predators; a plant that has anti-insect phytoalexins may not have the ability to repel a fungal attack. 3-Indoleacetonitrile is common in cruciferous vegetables such as cabbage, cauliflower, broccoli, and Brussels sprouts. Dietary indoles in cruciferous vegetables induce cytochrome P450 enzymes and have prevented tumours in various animal models. Consumption of Brassica vegetables is associated with a reduced risk of cancer of the alimentary tract in animal models and human populations (PMID:15612779, 15884814, 2342128, 3014947, 3880668, 6334634, 6419397, 6426808, 6584878, 6725517, 6838646, 7123561).
3-Methylcrotonylglycine is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acyl glycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13) which is an enzyme that catalyzes the chemical reaction: acyl-CoA + glycine < -- > CoA + N-acylglycine. 3-Methylcrotonylglycine is a normal amino acid metabolite found in urine. Increased levels of this metabolite are found in patients suffering from leucine catabolic disorders, such as 3-methylcrotonyl-CoA carboxylase deficiency. 3-Methylcrotonylglycine is often considered to be a diagnostic marker of organic acidemias (PMID 11170888). Moreover, 3-methylcrotonylglycine is found to be associated with 3-hydroxy-3-methylglutaryl-CoA lyase deficiency and propionic acidemia, which are also inborn errors of metabolism.
3-Methylcytidine belongs to the class of organic compounds known as pyrimidine nucleosides. These are compounds comprising a pyrimidine base attached to a ribosyl or deoxyribosyl moiety. 3-Methylcytidine is a potential urinary biomarker of whole grain intake (PMID: 27805021). 3-Methylcytidine has been identified in the human placenta (PMID: 32033212).
3-Nitrotyrosine, also known as nitrotyrosine is a product of tyrosine nitration mediated by reactive nitrogen species such as peroxynitrite anion and nitrogen dioxide. Nitrotyrosine is identified as an indicator or marker of cell damage, inflammation as well as NO (nitric oxide) production. Nitrotyrosine is formed in the presence of the active metabolite NO. Nitrotyrosine belongs to the class of organic compounds known as tyrosine and derivatives. Tyrosine and derivatives are compounds containing tyrosine or a derivative thereof resulting from reaction of tyrosine at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom.
3-Octanol is found in alcoholic beverages. 3-Octanol is present in Mentha species oils, sage, soybeans, porcini (Boletus edulis), wines and other foodstuffs. 3-Octanol is a flavouring agent
Ureidopropionic acid, also known as 3-ureidopropanoate or N-carbamoyl-beta-alanine, belongs to the class of organic compounds known as ureas. Ureas are compounds containing two amine groups joined by a carbonyl (C=O) functional group. Ureidopropionic acid is an intermediate in the metabolism of uracil. More specifically, it is a breakdown product of dihydrouracil and is produced by the enzyme dihydropyrimidase. It is further decomposed into beta-alanine via the enzyme beta-ureidopropionase. Ureidopropionic acid is essentially a urea derivative of beta-alanine. High levels of ureidopropionic acid are found in individuals with beta-ureidopropionase (UP) deficiency (PMID: 11675655). Enzyme deficiencies in pyrimidine metabolism are associated with a risk for severe toxicity against the antineoplastic agent 5-fluorouracil. Ureidopropionic acid has been detected, but not quantified in, several different foods, such as gram beans, broccoli, climbing beans, oriental wheat, and mandarin orange (clementine, tangerine). This could make ureidopropionic acid a potential biomarker for the consumption of these foods.
4-Acetamidobutanoic acid, also known as 4-acetamidobutanoate or N-acetyl-4-aminobutyric acid, is a member of the class of compounds known as gamma amino acids and derivatives. These compounds are amino acids having an -NH2 group attached to the gamma carbon atom. 4-Acetamidobutanoic acid is soluble in water. 4-Acetamidobutanoic acid can be found in a number of food items such as Rubus species (blackberry, raspberry), cassava, pepper (Capsicum frutescens), and napa cabbage, which makes 4-acetamidobutanoic acid a potential biomarker for the consumption of these food products. 4-Acetamidobutanoic acid can be found in blood, feces, and urine, as well as in human prostate tissue. 4-Acetamidobutanoic acid exists in all eukaryotes, ranging from yeast to humans. 4-Acetamidobutanoic acid is a GABA derivative, a product of the urea cycle and the metabolism of amino groups, and the product of NAD-linked aldehyde dehydrogenase (EC 1.2.1.3) (KEGG).
Tranexamic Acid is only found in individuals that have used or taken this drug. It is an antifibrinolytic hemostatic used in severe hemorrhage. [PubChem]Tranexamic acid competitively inhibits activation of plasminogen (via binding to the kringle domain), thereby reducing conversion of plasminogen to plasmin (fibrinolysin), an enzyme that degrades fibrin clots, fibrinogen, and other plasma proteins, including the procoagulant factors V and VIII. Tranexamic acid also directly inhibits plasmin activity, but higher doses are required than are needed to reduce plasmin formation.
4-aminophenol is considered a minor nephrotoxic metabolite of phenacetin and acetaminophen (paracetamol) in man. 4-Aminophenol can undergo autoxidations and metal-catalyzed and enzymatic oxidations in man to produce reactive oxygen species. (PMID 1713494).
4-Guanidinobutanoic acid, also known as gamma-guanidinobutyrate or 4-(carbamimidamido)butanoate, belongs to the class of organic compounds known as gamma amino acids and derivatives. These are amino acids having a (-NH2) group attached to the gamma carbon atom. 4-Guanidinobutanoic acid is a normal metabolite present in low concentrations. 4-Guanidinobutanoic acid exists in all eukaryotes, ranging from yeast to humans. Outside of the human body, 4-Guanidinobutanoic acid has been detected, but not quantified in a few different foods, such as apples, french plantains, and loquats. This could make 4-guanidinobutanoic acid a potential biomarker for the consumption of these foods. Patients with hyperargininemia have an arginase deficiency which leads to blockade of the urea cycle in the last step with several clinical symptoms. Owing to the arginase deficiency this patients accumulate arginine which leads eventually to epileptogenic guanidino compounds (PMID 7752905).
Hexylresorcinol, also known as adrover or antascarin, belongs to the class of organic compounds known as resorcinols. Resorcinols are compounds containing a resorcinol moiety, which is a benzene ring bearing two hydroxyl groups at positions 1 and 3. The agent also demonstrates mild antiseptic activity as well as an apparent anti-inflammatory, demulcent action . Moreover, such studies have also shown that hexylresorcinol is seemingly capable of dose-dependent induction of SCC-9 cell apoptosis as well as the inhibition of transglutaminase-2 enzyme activity which can facilitate chemotherapy resistance . Hexylresorcinol is a potentially toxic compound. Hexylresorcinol belongs to the family of Resorcinols. Regarding the metabolism of hexylresorcinol, it has been reported that excretion of the compound in the urine is largely in the form of an ethereal sulfate conjugate. Ultimately, it is also reported that glutathione depletion increases tyrosinase activity in human melanoma cells, which makes hexylresorcinol's effects on tyrosinase desirable . Nevertheless, it is useful for hexylresorcinol to have both anesthetic and certain antiseptic actions for its use in treating various relatively self-limiting scrapes and sore throats that are treated by the over-the-counter products that feature the compound. It is proposed that hexylresorcinol can bind to tyrosinase directly and inhibits its enzyme activity . It can be found in topical applications for minor skin infections and in oral solutions or throat lozenges for pain relief and first aid antiseptic.
Diacetone alcohol is found in fruits. Diacetone alcohol is isolated from the arctic bramble Rubus arcticu
4-Hydroxybenzaldehyde, also known as 4-formylphenol or 4-hydroxybenzenecarbonal, belongs to the class of organic compounds known as hydroxybenzaldehydes. These are organic aromatic compounds containing a benzene ring carrying an aldehyde group and a hydroxyl group. A hydroxybenzaldehyde that is benzaldehyde substituted with a hydroxy group at position C-4. 4-Hydroxybenzaldehyde exists in all living organisms, ranging from bacteria to humans. 4-Hydroxybenzaldehyde is a sweet, almond, and balsam tasting compound. 4-Hydroxybenzaldehyde is found, on average, in the highest concentration within vinegars and oats. 4-Hydroxybenzaldehyde has also been detected, but not quantified, in several different foods, such as cardoons, colorado pinyons, oyster mushrooms, common chokecherries, and potato. This could make 4-hydroxybenzaldehyde a potential biomarker for the consumption of these foods.
4-Hydroxyhippuric acid is a microbial end-product derived from polyphenol metabolism by the microflora in the intestine (PMID: 22932811). It is derived from 4-hydroxybenzoic acid derivatives which may undergo glycination in the liver and kidney (PMID: 20615997). 4-Hydroxyhippuric acid has been identified in the human placenta (PMID: 32033212).
4-Hydroxyphenylpyruvic acid (4-HPPA) is a keto acid that is involved in the tyrosine catabolism pathway. It is a product of the enzyme (R)-4-hydroxyphenyllactate dehydrogenase (EC 1.1.1.222) and is formed during tyrosine metabolism. The conversion from tyrosine to 4-HPPA is catalyzed by tyrosine aminotransferase. Additionally, 4-HPPA can be converted to homogentisic acid which is one of the precursors to ochronotic pigment. The enzyme 4-hydroxyphenylpyruvic acid dioxygenase (HPD) catalyzes the reaction that converts 4-hydroxyphenylpyruvic acid to homogentisic acid. A deficiency in the catalytic activity of HPD is known to lead to tyrosinemia type III, an autosomal recessive disorder characterized by elevated levels of blood tyrosine and massive excretion of tyrosine derivatives into urine. It has been shown that hawkinsinuria, an autosomal dominant disorder characterized by the excretion of 'hawkinsin,' may also be a result of HPD deficiency (PMID: 11073718). Moreover, 4-hydroxyphenylpyruvic acid is also found to be associated in phenylketonuria, which is also an inborn error of metabolism. There are two isomers of HPPA, specifically 4HPPA and 3HPPA, of which 4HPPA is the most common. 4-HPPA has been found to be a microbial metabolite in Escherichia (ECMDB).
5-(2-Hydroxyethyl)-4-methylthiazole, also known as 4-methyl-5-(2'-hydroxyethyl)-thiazole or 4-methyl-5-thiazolethanol, belongs to the class of organic compounds known as 4,5-disubstituted thiazoles. 4,5-disubstituted thiazoles are compounds containing a thiazole ring substituted at positions 4 and 5 only. 5-(2-Hydroxyethyl)-4-methylthiazole exists in all living species, ranging from bacteria to humans. 5-(2-Hydroxyethyl)-4-methylthiazole is a sulfur tasting compound. 5-(2-Hydroxyethyl)-4-methylthiazole has been detected, but not quantified, in several different foods, such as kohlrabis, red bell peppers, citrus, avocado, and black-eyed pea. This could make 5-(2-hydroxyethyl)-4-methylthiazole a potential biomarker for the consumption of these foods. A 1,3-thiazole that is thiazole substituted by a methyl group at position 4 and a 2-hydroxyethyl group at position 5.
4-methylumbelliferone is a substrate for: Liver carboxylesterase 1, Cocaine esterase, and S-formylglutathione hydrolase.
4-Methylumbelliferyl acetate is found in fenugreek. 4-Methylumbelliferyl acetate is isolated from fenugreek (Trigonella foenum-graecum).
4-Pyridoxic acid is a member of the class of compounds known as methylpyridines. More specifically it is a 2-methylpyridine derivative substituted by a hydroxy group at C-3, a carboxy group at C-4, and a hydroxymethyl group at C-5. 4-Pyridoxic acid is the catabolic product of vitamin B6 (also known as pyridoxine, pyridoxal and pyradoxamine) and is excreted in the urine. Urinary levels of 4-pyridoxic acid are lower in females than in males and will be reduced even further in persons with a riboflavin deficiency. 4-Pyridoxic acid is formed by the action of aldehyde oxidase I (an endogenous enzyme) and by microbial enzymes (pyridoxal 4-dehydrogenase), an NAD-dependent aldehyde dehydrogenase. 4-pyridoxic acid can be further broken down by the gut microflora via the enzyme known as 4-pyridoxic acid dehydrogenase. This enzyme catalyzes the four-electron oxidation of 4-pyridoxic acid to 3-hydroxy-2-methylpyridine-4,5-dicarboxylate, using nicotinamide adenine dinucleotide (NAD) as a cofactor.
5'-Methylthioadenosine, also known as MTA or thiomethyladenosine, belongs to the class of organic compounds known as 5'-deoxy-5'-thionucleosides. These are 5'-deoxyribonucleosides in which the ribose is thio-substituted at the 5'position by a S-alkyl group. 5'-Methylthioadenosine is metabolized solely by MTA-phosphorylase, to yield 5-methylthioribose-1-phosphate and adenine, a crucial step in the methionine and purine salvage pathways, respectively. 5'-Methylthioadenosine exists in all living species, ranging from bacteria to humans. 5'-Methylthioadenosine (MTA) is a naturally occurring sulfur-containing nucleoside present in all mammalian tissues. Within humans, 5'-methylthioadenosine participates in a number of enzymatic reactions. In particular, 5'-methylthioadenosine and spermidine can be biosynthesized from S-adenosylmethioninamine and putrescine through the action of the enzyme spermidine synthase. In addition, 5'-methylthioadenosine can be converted into 5-methylthioribose 1-phosphate and L-methionine; which is catalyzed by the enzyme S-methyl-5'-thioadenosine phosphorylase. It is produced from S-adenosylmethionine mainly through the polyamine biosynthetic pathway, where it behaves as a powerful inhibitory product. For instance, 5'-Methylthioadenosine has been shown to influence the regulation of gene expression, proliferation, differentiation, and apoptosis (PMID:15313459). In humans, 5'-methylthioadenosine is involved in the metabolic disorder called hypermethioninemia. Outside of the human body, 5'-Methylthioadenosine has been detected, but not quantified in several different foods, such as soursops, allspices, summer grapes, alaska wild rhubarbs, and breadfruits. Elevated excretion appears in children with severe combined immunodeficiency syndrome (SCID) (PMID:3987052). Evidence suggests that 5'-Methylthioadenosine can affect cellular processes in many ways. 5'-Methylthioadenosine can be found in human urine.
Dihydrothymine, also known as 5,6-dihydro-5-methyluracil or 5,6-dihydrothymine, (S)-isomer, is a member of the class of compounds known as hydropyrimidines. Hydropyrimidines are compounds containing a hydrogenated pyrimidine ring (i.e. containing less than the maximum number of double bonds.). Dihydrothymine is soluble (in water) and a very weakly acidic compound (based on its pKa). Dihydrothymine can be found in a number of food items such as hyssop, arrowroot, nopal, and red rice, which makes dihydrothymine a potential biomarker for the consumption of these food products. Dihydrothymine can be found primarily in blood, cerebrospinal fluid (CSF), saliva, and urine, as well as in human prostate tissue. Dihydrothymine exists in all living organisms, ranging from bacteria to humans. In humans, dihydrothymine is involved in the pyrimidine metabolism. Dihydrothymine is also involved in few metabolic disorders, which include beta ureidopropionase deficiency, dihydropyrimidinase deficiency, MNGIE (mitochondrial neurogastrointestinal encephalopathy), and UMP synthase deficiency (orotic aciduria). Moreover, dihydrothymine is found to be associated with beta-ureidopropionase deficiency and dihydropyrimidinase deficiency. Dihydrothymine is a non-carcinogenic (not listed by IARC) potentially toxic compound. Dihydrothymine is an intermediate in the metabolism of thymine . Dihydropyrimidine dehydrogenase catalyzes the reduction of thymine to 5, 6-dihydrothymine then dihydropyrimidinase hydrolyzes 5, 6-dihydrothymine to N-carbamyl-b-alanine. Finally, beta-ureidopropionase catalyzes the conversion of N-carbamyl-b-alanine to beta-alanine. Accumulation of dihydrothymine in the body has been shown to be toxic (T3DB).
Dimethylbenzimidazole is an intermediate in Riboflavin metabolism. Dimethylbenzimidazole is the second to last step for the synthesis of alpha-Ribazole. It is converted from Riboflavin then it is converted to N1-(5-Phospho-alpha-D-ribosyl)-5,6-dimethylbenzimidazole via the enzyme nicotinate-nucleotide--dimethylbenzimidazole phosphoribosyltransferase (EC 2.4.2.21).
Mesalazine is only found in individuals that have used or taken this drug. It is an anti-inflammatory agent, structurally related to the salicylates, which is active in inflammatory bowel disease. It is considered to be the active moiety of sulphasalazine. (From Martindale, The Extra Pharmacopoeia, 30th ed)Although the mechanism of action of mesalazine is not fully understood, it appears to be topical rather than systemic. Mucosal production of arachidonic acid metabolites, both through the cyclooxygenase pathways, i.e., prostanoids, and through the lipoxygenase pathways, i.e., leukotrienes and hydroxyeicosatetraenoic acids, is increased in patients with chronic inflammatory bowel disease, and it is possible that mesalazine diminishes inflammation by blocking cyclooxygenase and inhibiting prostaglandin production in the colon.
7alpha-Hydroxycholesterol is an oxysterol and can serve as a biomarker for lipid peroxidation (PMID: 17386651). Products of cholesterol oxidation accumulate within atherosclerotic plaque and have been proposed to contribute to inflammatory signalling in the diseased artery (PMID: 17364953). 7alpha-Hydroxycholesterol is a cholesterol oxide that has been described as a biomarker of oxidative stress in subjects with impaired glucose tolerance and diabetes (PMID: 16634125). 7alpha-Hydroxycholesterol has been identified in the human placenta (PMID: 32033212).
Flucytosine is only found in individuals that have used or taken this drug. It is a fluorinated cytosine analog that is used as an antifungal agent. [PubChem]Although the exact mode of action is unknown, it has been proposed that flucytosine acts directly on fungal organisms by competitive inhibition of purine and pyrimidine uptake and indirectly by intracellular metabolism to 5-fluorouracil. Flucytosine enters the fungal cell via cytosine permease; thus, flucytosine is metabolized to 5-fluorouracil within fungal organisms. The 5-fluorouracil is extensively incorporated into fungal RNA and inhibits synthesis of both DNA and RNA. The result is unbalanced growth and death of the fungal organism. It also appears to be an inhibitor of fungal thymidylate synthase.
5-Hydroxyindoleacetic acid, also known as 5-hydroxyindole-3-acetate or 5-HIAA, belongs to the class of organic compounds known as indole-3-acetic acid derivatives. Indole-3-acetic acid derivatives are compounds containing an acetic acid (or a derivative) linked to the C3 carbon atom of an indole. 5-Hydroxyindoleacetic acid exists in all living organisms, ranging from bacteria to humans. In humans, 5-hydroxyindoleacetic acid is a breakdown product of serotonin that is excreted in the urine and it also participates in a number of enzymatic reactions. 5-hydroxyindoleacetic acid can be biosynthesized from 5-hydroxyindoleacetaldehyde; which is catalyzed by the mitochondrial enzyme aldehyde dehydrogenase. In addition, 5-hydroxyindoleacetic acid and S-adenosylmethionine can be converted into 5-methoxyindoleacetate and S-adenosylhomocysteine through its interaction with the enzyme acetylserotonin O-methyltransferase. 5-Hydroxyindoleacetic acid is also involved in the metabolism of tryptophan. 5-Hydroxyindoleacetic acid has been found to be associated with several human diseases such as brunner syndrome, friedreich's ataxia, schizophrenia, and olivopontocerebral atrophy; 5-hydroxyindoleacetic acid has also been linked to the inborn metabolic disorder sepiapterin reductase deficiency. Elevated levels of 5-hydroxyindoleacetic acid in urine (>20 uM) are indicative of appendicitis and gastroenteritis (PMID: 11462886). Serotonin and 5-Hydroxyindoleacetic acid are produced in excess amounts by carcinoid tumors, and levels of these substances may be measured in the urine to test for carcinoid tumors (NCI). 5-Hydroxyindoleacetic acid has also been found to be a product of human gut microbiota.
5-Methoxyindoleacetate, also known as 5-methoxy-IAA or 5-MIAA, belongs to the class of organic compounds known as indole-3-acetic acid derivatives. Indole-3-acetic acid derivatives are compounds containing an acetic acid (or a derivative) linked to the C3 carbon atom of an indole. 5-Methoxyindoleacetic acid is formed through oxidative deamination. It is identified in the urine, and the concentration is determined to be 1.3 µg/mL using GC-MS (PMID: 12908946). An increase in urinary 5-MIAA excretion was shown in patients with cancer of the stomach, rectum, and lung (PMID: 2446428).
Bergapten, also known as O-methylbergaptol or heraclin, belongs to the class of organic compounds known as 5-methoxypsoralens. These are psoralens containing a methoxy group attached at the C5 position of the psoralen group. Bergapten is found, on average, in the highest concentration within a few different foods, such as anises, figs, and parsnips and in a lower concentration in carrots, fennels, and celery stalks. Bergapten has also been detected, but not quantified, in several different foods, such as coconuts, pepper (c. frutescens), corianders, sesbania flowers, and cardamoms. This could make bergapten a potential biomarker for the consumption of these foods. It is also found in rose hip, sweet marjoram, greenthread tea, and tartary buckwheat. Bergapten is a potentially toxic compound. Bergapten is a major constituent of bergamot oil (Citrus bergamia). Present in celery, especially the outer leaves, and other common grocery vegetables. Implicated in photodermatitis among grocery workers. Bergapten was under investigation in clinical trial NCT00533195 "Comparison of UVA1 Phototherapy Versus Photochemotherapy for Patients With Severe Generalized Atopic Dermatitis".
5-Methoxytryptamine, also known as mexamine or 5-MT, belongs to the class of organic compounds known as tryptamines and derivatives. Tryptamines and derivatives are compounds containing the tryptamine backbone, which is structurally characterized by an indole ring substituted at the 3-position by an ethanamine. It is biosynthesized via the deacetylation of melatonin in the pineal gland. 5-MT acts as a full agonist at the 5-HT1, 5-HT2, 5-HT4, 5-HT6, and 5-HT7 receptors. 5-Methoxytryptamine exists in all living organisms, ranging from bacteria to humans. Its affinity for the 5-HT5A receptor is unknown. It has no affinity for the 5-HT3 receptor and is affinity for the 5-HT1E receptor is very weak in comparison to the other 5-HT1 receptors. 5-MT has been shown to occur naturally in the body in low levels.
5-Methylcytidine belongs to the class of organic compounds known as pyrimidine nucleosides. Pyrimidine nucleosides are compounds comprising a pyrimidine base attached to a ribosyl or deoxyribosyl moiety.
Ribothymidine is an endogenous methylated nucleoside found in human fluids; methylated purine bases are present in higher amounts in tumor-bearing patients compared to healthy controls.DNA hypermethylation is a common finding in malignant cells and has been explored as a therapeutic target for hypomethylating agents. When chemical bonds to DNA, the DNA becomes damaged and proper and complete replication cannot occur to make the normal intended cell. A DNA adduct is an abnormal piece of DNA covalently-bonded to a cancer-causing chemical. This has shown to be the start of a cancerous cell, or carcinogenesis. DNA adducts in scientific experiments are used as bio-markers and as such are themselves measured to reflect quantitatively, for comparison, the amount of cancer in the subject. (PMID:3506820, 17044778, 17264127, 16799933).
Aesculetin, also known as cichorigenin or cichoriin aglucon, belongs to the class of organic compounds known as 6,7-dihydroxycoumarins. These are coumarins bearing two hydroxyl groups at positions 6 and 7 of the coumarin skeleton, respectively. Aesculetin is found, on average, in the highest concentration within sherries. Aesculetin has also been detected, but not quantified, in several different foods, such as horseradish, carrots, dandelions, grape wines, and highbush blueberries. This could make aesculetin a potential biomarker for the consumption of these foods.
(R)-Sulcatol is found in herbs and spices. (R)-Sulcatol occurs in lemongrass oi
6-Methylmercaptopurine is a metabolite of mercaptopurine. Mercaptopurine (also called 6-mercaptopurine, 6-MP or its brand name Purinethol) is an immunosuppressive drug. It is a thiopurine. (Wikipedia)
7-methylguanosine is an endogenous methylated nucleoside found in human fluids; methylated purine bases are present in higher amounts in tumor-bearing patients compared to healthy controls.DNA hypermethylation is a common finding in malignant cells and has been explored as a therapeutic target for hypomethylating agents. When chemical bonds to DNA, the DNA becomes damaged and proper and complete replication cannot occur to make the normal intended cell. A DNA adduct is an abnormal piece of DNA covalently-bonded to a cancer-causing chemical. This has shown to be the start of a cancerous cell, or carcinogenesis. DNA adducts in scientific experiments are used as bio-markers and as such are themselves measured to reflect quantitatively, for comparison, the amount of cancer in the subject. 7-Methylguanosine is a substrate for purine-nucleoside phosphorylase and Eukaryotic translation initiation factor 4E. (PMID:3506820, 17044778, 17264127, 16799933).
Acetaminophen glucuronide is a natural human metabolite of Acetaminophen generated in the liver by UDP glucuonyltransferase. Glucuronidation is used to assist in the excretion of toxic substances, drugs or other substances that cannot be used as an energy source. Glucuronic acid is attached via a glycosidic bond to the substance, and the resulting glucuronide, which has a much higher water solubility than the original substance, is eventually excreted by the kidneys. Acetaminophen glucuronide is found to be associated with beta-thalassemia, which is an inborn error of metabolism.
N-Acetylarylamine is an odourless solid chemical of leaf or flake-like appearance. It is also known as acetanilide, N-phenylacetamide, acetanil, or acetanilid, and was formerly known by the trade name Antifebrin. N-Acetylarylamine has analgesic and fever-reducing properties; it is in the same class of drugs as acetaminophen (paracetamol). Under the name acetanilid it formerly figured in the formula of a number of patent medicines and over the counter drugs. In 1948, Julius Axelrod and Bernard Brodie discovered that acetanilide is much more toxic in these applications than other drugs, causing methemoglobinemia and ultimately doing damage to the liver and kidneys. As such, acetanilide has largely been replaced by less toxic drugs, in particular acetaminophen, which is a metabolite of acetanilide and whose use Axelrod and Brodie suggested in the same study.
Acetohydroxamic Acid, a synthetic drug derived from hydroxylamine and ethyl acetate, is similar in structure to urea. In the urine, it acts as an antagonist of the bacterial enzyme urease. Acetohydroxamic Acid has no direct antimicrobial action and does not acidify urine directly. It is used, in addition to antibiotics or medical procedures, to treat chronic urea-splitting urinary infections.
The excellent tolerability of therapeutic doses of paracetamol (acetaminophen) is a major factor in the very wide use of the drug. The major problem in the use of paracetamol is its hepatotoxicity after an overdose. Hepatotoxicity has also been reported after therapeutic doses, but critical analysis indicates that most patients with alleged toxicity from therapeutic doses have taken overdoses. Importantly, prospective studies indicate that therapeutic doses of paracetamol are an unlikely cause of hepatotoxicity in patients who ingest moderate to large amounts of alcohol (PMID: 15733027). Single doses of paracetamol are effective analgesics for acute postoperative pain and give rise to few adverse effects (PMID: 14974073). Acetaminophen (AAP) overdose and the resulting hepatotoxicity is an important clinical problem. In addition, AAP is widely used as a prototype hepatotoxin to study mechanisms of chemical-induced cell injury and to test the hepatoprotective potential of new drugs and herbal medicines. Because of its importance, the mechanisms of AAP-induced liver cell injury have been extensively investigated and controversially discussed for many years (PMID: 16863451).
Adenine is a purine base. Adenine is found in both DNA and RNA. Adenine is a fundamental component of adenine nucleotides. Adenine forms adenosine, a nucleoside, when attached to ribose, and deoxyadenosine when attached to deoxyribose; it forms adenosine triphosphate (ATP), a nucleotide, when three phosphate groups are added to adenosine. Adenosine triphosphate is used in cellular metabolism as one of the basic methods of transferring chemical energy between chemical reactions. Purine inborn errors of metabolism (IEM) are serious hereditary disorders, which should be suspected in any case of neonatal fitting, failure to thrive, recurrent infections, neurological deficit, renal disease, self-mutilation and other manifestations. Investigation usually starts with uric acid (UA) determination in urine and plasma. (OMIM 300322, 229600, 603027, 232400, 232600, 232800, 201450, 220150, 232200, 162000, 164050, 278300). (PMID: 17052198, 17520339).
Cyclic AMP (cAMP) or cyclic adenosine monophosphate is an adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. cAMP is found in all organisms ranging from bacteria to plants to animals. In humans and other mammals it is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon and ACTH. cAMP is synthesized from ATP by adenylate cyclase. Adenylate cyclase is located at the inner side of cell membranes. Adenylate cyclase is activated by the hormones glucagon and adrenaline and by G protein. Liver adenylate cyclase responds more strongly to glucagon, and muscle adenylate cyclase responds more strongly to adrenaline. cAMP decomposition into AMP is catalyzed by the enzyme phosphodiesterase. cAMP is primarily used for intracellular signal transduction, such as transferring into cells the effects of hormones like glucagon and adrenaline, which cannot pass through the plasma membrane. cAMP is also involved in the activation of protein kinases. In addition, cAMP binds to and regulates the function of ion channels such as the HCN channels. Hyperpolarization-activated cyclic nucleotide‚Äìgated (HCN) channels are integral membrane proteins that serve as nonselective voltage-gated cation channels in the plasma membranes of heart and brain cells. HCN channels are sometimes referred to as pacemaker channels because they help to generate rhythmic activity within groups of heart and brain cells.
Adenylic acid. Adenine nucleotide containing one phosphate group esterified to the sugar moiety in the 2'-, 3'-, or 5'-position. 3'-AMP has been identified in the human placenta (PMID: 32033212).
Adenosine is a nucleoside that is composed of adenine and D-ribose. Adenosine or adenosine derivatives play many important biological roles in addition to being components of DNA and RNA. For instance, adenosine plays an important role in energy transfer as adenosine triphosphate (ATP) and adenosine diphosphate (ADP). It also plays a role in signal transduction as cyclic adenosine monophosphate (cAMP). Adenosine itself is both a neurotransmitter and potent vasodilator. When administered intravenously adenosine causes transient heart block in the AV node. Due to the effects of adenosine on AV node-dependent supraventricular tachycardia, adenosine is considered a class V antiarrhythmic agent. Overdoses of adenosine intake (as a drug) can lead to several side effects including chest pain, feeling faint, shortness of breath, and tingling of the senses. Serious side effects include a worsening dysrhythmia and low blood pressure. When present in sufficiently high levels, adenosine can act as an immunotoxin and a metabotoxin. An immunotoxin disrupts, limits the function, or destroys immune cells. A metabotoxin is an endogenous metabolite that causes adverse health effects at chronically high levels. Chronically high levels of adenosine are associated with adenosine deaminase deficiency. Adenosine is a precursor to deoxyadenosine, which is a precursor to dATP. A buildup of dATP in cells inhibits ribonucleotide reductase and prevents DNA synthesis, so cells are unable to divide. Since developing T cells and B cells are some of the most mitotically active cells, they are unable to divide and propagate to respond to immune challenges. High levels of deoxyadenosine also lead to an increase in S-adenosylhomocysteine, which is toxic to immature lymphocytes.
Asymmetric dimethylarginine (ADMA) is a naturally occurring chemical found in blood plasma. It is a metabolic by-product of continual protein modification processes in the cytoplasm of all human cells. It is closely related to L-arginine, a conditionally-essential amino acid. ADMA interferes with L-arginine in the production of nitric oxide, a key chemical to endothelial and hence cardiovascular health. Asymmetric dimethylarginine is created in protein methylation, a common mechanism of post-translational protein modification. This reaction is catalyzed by an enzyme set called S-adenosylmethionine protein N-methyltransferases (protein methylases I and II). The methyl groups transferred to create ADMA are derived from the methyl group donor S-adenosylmethionine, an intermediate in the metabolism of homocysteine. (Homocysteine is an important blood chemical, because it is also a marker of cardiovascular disease). After synthesis, ADMA migrates into the extracellular space and thence into blood plasma. Asymmetric dimethylarginine is measured using high performance liquid chromatography. ADMA has been identified as a uremic toxin according to the European Uremic Toxin Working Group (PMID: 22626821).
Adrenosterone is a steroid hormone with weak androgenic effect. It was first isolated in 1936 from the adrenal cortex by Tadeus Reichstein at the Pharmaceutical Institute in the University of Basel. Originally, adrenosterone was called Reichstein's substance G.(Wikipedia). Andrenosterone is created from androst-4-ene-3,17-dione by the work of two enzymes, CYP11B (E1.14.15.4) and 11beta-hydroxysteroid dehydrogenase [EC:1.1.1.146].
Agmatine ((4-aminobutyl)guanidine, NH2-CH2-CH2-CH2-CH2-NH-C(-NH2)(=NH)) is the decarboxylation product of the amino acid arginine and is an intermediate in polyamine biosynthesis. It is a putative neurotransmitter. It is synthesized in the brain, stored in synaptic vesicles, accumulated by uptake, released by membrane depolarization, and inactivated by agmatinase. Agmatine binds to 2-adrenergic receptor and imidazoline binding sites, and blocks NMDA receptors and other cation ligand-gated channels. Agmatine inhibits nitric oxide synthase (NOS), and induces the release of some peptide hormones. Treatment with exogenous agmatine exerts neuroprotective effects in animal models of neurotrauma.
The ATP-dependent carboxylate-amine/thiol ligase superfamily is known to contain enzymes catalyzing the formation of various types of peptide, one of which is d-alanyl-d-alanine.(PMID: 16030213). The glycopeptide antibiotic vancomycin acts by binding to the D-alanyl-D-alanine terminus of the cell wall precursor lipid II in the cytoplasmic membrane.(PMID: 17418637). D-alanine-D-alanine ligase from Thermotoga maritima ATCC 43589 (TmDdl) was a useful biocatalyst for synthesizing D-amino acid dipeptides.D-Alanine-D-alanine ligase (Ddl) catalyzes the biosynthesis of an essential bacterial peptidoglycan precursor D-alanyl-D-alanine and it represents an important target for development of new antibacterial drugs. (PMID: 17267218). D-Alanyl-D-alanine is a microbial metabolite.
Alanylisoleucine is a dipeptide composed of alanine and isoleucine. It is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis.
Alanylvaline is a dipeptide composed of alanine and valine. It is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis.
Albendazole is only found in individuals that have used or taken this drug. It is a benzimidazole broad-spectrum anthelmintic structurally related to mebendazole that is effective against many diseases. (From Martindale, The Extra Pharmacopoeia, 30th ed, p38)Albendazole causes degenerative alterations in the tegument and intestinal cells of the worm by binding to the colchicine-sensitive site of tubulin, thus inhibiting its polymerization or assembly into microtubules. The loss of the cytoplasmic microtubules leads to impaired uptake of glucose by the larval and adult stages of the susceptible parasites, and depletes their glycogen stores. Degenerative changes in the endoplasmic reticulum, the mitochondria of the germinal layer, and the subsequent release of lysosomes result in decreased production of adenosine triphosphate (ATP), which is the energy required for the survival of the helminth. Due to diminished energy production, the parasite is immobilized and eventually dies.
Salbutamol is a short-acting, selective beta2-adrenergic receptor agonist used in the treatment of asthma and COPD. It is 29 times more selective for beta2 receptors than beta1 receptors giving it higher specificity for pulmonary beta receptors versus beta1-adrenergic receptors located in the heart. Salbutamol is formulated as a racemic mixture of the R- and S-isomers. The R-isomer has 150 times greater affinity for the beta2-receptor than the S-isomer and the S-isomer has been associated with toxicity. This lead to the development of levalbuterol, the single R-isomer of salbutamol. However, the high cost of levalbuterol compared to salbutamol has deterred wide-spread use of this enantiomerically pure version of the drug. Salbutamol is generally used for acute episodes of bronchospasm caused by bronchial asthma, chronic bronchitis and other chronic bronchopulmonary disorders such as chronic obstructive pulmonary disorder (COPD). It is also used prophylactically for exercise-induced asthma
Alfuzosin is only found in individuals that have used or taken this drug. It is an alpha-adrenergic blocker used to treat benign prostatic hyperplasia (BPH). It works by relaxing the muscles in the prostate and bladder neck, making it easier to urinate. [Wikipedia]Alfuzosin is a non-subtype specific alpha(1)-adrenergic blocking agent that exhibits selectivity for alpha(1)-adrenergic receptors in the lower urinary tract. Inhibition of these adrenoreceptors leads to the relaxation of smooth muscle in the bladder neck and prostate, resulting in the improvement in urine flow and a reduction in symptoms in benign prostate hyperplasia. Alfuzosin also inhibits the vasoconstrictor effect of circulating and locally released catecholamines (epinephrine and norepinephrine), resulting in peripheral vasodilation.
L-allothreonine is the L-enantiomer of allothreonine. It has a role as an Escherichia coli metabolite and a Saccharomyces cerevisiae metabolite. It is an enantiomer of a D-allothreonine. It is a tautomer of a L-allothreonine zwitterion. Allothreonine is the substrate of the enzyme Serine hydroxymethyltransferase1 (SHMT, EC 2.1.2.1), a human cytoplasmic mRNA binding protein. SHMT uses pyridoxal 5'-phosphate (PLP) and tetrahydropteroylglutamate (H4PteGlu) as coenzymes and catalyzes the reversible interconversion of serine and glycine. In addition to these physiological reactions, SHMT also catalyzes, in the absence of H4PteGlu, the retroaldol cleavage of several 3-hydroxyamino acids, such as allothreonine. Allothreonine is a plant metabolite that appears in the human diet in variable concentrations depending on: plant species, physiological changes during plant growth, senescence, and reactions to environmental stress or to changes due to plant transformation (PMID:10858298, 10952545).
Alosetron is a 5-HT3 antagonist used only for the management of severe diarrhoea-predominant irritable bowel syndrome (IBS) in women. Alosetron has an antagonist action on the 5-HT3 receptors and thus may modulate serotonin-sensitive gastrointestinal (GI) processes. Alosetron was voluntarily withdrawn from the US market in November 2000 by the manufacturer due to numerous reports of severe adverse effects including ischemic colitis, severely obstructed or ruptured bowel, and death. In June 2002, the FDA approved a supplemental new drug application allowing the remarketing of the drug under restricted conditions of use.
2-oxo-4-methylthiobutanoate, also known as 2-keto-4-methylthiobutyric acid, 2-keto-4-methylthiobutyrate or 4-(methylsulfanyl)-2-oxobutanoic acid, is a member of the class of compounds known as thia- fatty acids. Thia-fatty acids are fatty acid derivatives obtained by insertion of a sulfur atom at specific positions in the chain. Thus, 2-oxo-4-methylthiobutanoate is a fatty acid lipid molecule. 2-oxo-4-methylthiobutanoate is slightly soluble (in water) and a weakly acidic compound (based on its pKa). 2-oxo-4-methylthiobutanoate can be synthesized from L-methionine and butyric acid. 2-oxo-4-methylthiobutanoate can also be synthesized into S-adenosyl-4-methylthio-2-oxobutanoic acid. 2-oxo-4-methylthiobutanoate can be found in a number of food items such as cloves, highbush blueberries, common beets, and cashew nuts. 2-oxo-4-methylthiobutanoate can be found in urine. Within the cell, 2-oxo-4-methylthiobutanoate is primarily located in the cytoplasm and in the membrane. 2-oxo-4-methylthiobutanoate has been found in all living species, from bacteria to humans. In humans, 2-oxo-4-methylthiobutanoate is found to be involved in several metabolic disorders, some of those are S-adenosylhomocysteine (SAH) hydrolase deficiency, methylenetetrahydrofolate reductase deficiency (MTHFRD), methionine adenosyltransferase deficiency, and glycine N-methyltransferase deficiency. 4-Methylthio-2-oxobutanoic acid is the direct precursor of methional, which is a potent inducer of apoptosis in a BAF3 murine lymphoid cell line which is interleukin-3 (IL3)-dependent (PMID: 7848263).
Alprazolam is only found in individuals that have used or taken this drug. It is a triazolobenzodiazepine compound with antianxiety and sedative-hypnotic actions, that is efficacious in the treatment of panic disorders, with or without agoraphobia, and in generalized anxiety disorders. (From AMA Drug Evaluations Annual, 1994, p238)Benzodiazepines bind nonspecifically to benzodiazepine receptors BNZ1, which mediates sleep, and BNZ2, which affects muscle relaxation, anticonvulsant activity, motor coordination, and memory. As benzodiazepine receptors are thought to be coupled to gamma-aminobutyric acid-A (GABA<sub>A</sub>) receptors, this enhances the effects of GABA by increasing GABA affinity for the GABA receptor. Binding of the inhibitory neurotransmitter GABA to the site opens the chloride channel, resulting in a hyperpolarized cell membrane that prevents further excitation of the cell.
An antiviral that is used in the prophylactic or symptomatic treatment of influenza A. It is also used as an antiparkinsonian agent, to treat extrapyramidal reactions, and for postherpetic neuralgia. The mechanisms of its effects in movement disorders are not well understood but probably reflect an increase in synthesis and release of dopamine, with perhaps some inhibition of dopamine uptake. [PubChem]
A pyrazine compound inhibiting sodium reabsorption through sodium channels in renal epithelial cells. This inhibition creates a negative potential in the luminal membranes of principal cells, located in the distal convoluted tubule and collecting duct. Negative potential reduces secretion of potassium and hydrogen ions. Amiloride is used in conjunction with diuretics to spare potassium loss. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p705)
Amiodarone is only found in individuals that have used or taken this drug. It is an antianginal and antiarrhythmic drug. It increases the duration of ventricular and atrial muscle action by inhibiting Na,K-activated myocardial adenosine triphosphatase. There is a resulting decrease in heart rate and in vascular resistance. [PubChem]The antiarrhythmic effect of amiodarone may be due to at least two major actions. It prolongs the myocardial cell-action potential (phase 3) duration and refractory period and acts as a noncompetitive a- and b-adrenergic inhibitor.
Amisulpride (trade name Solian) is an antipsychotic drug sold by Sanofi-Aventis. It is not approved for use in the United States, but is approved for use in Europe and Australia for the treatment of psychoses and schizophrenia. Additionally, it is approved in Italy for the treatment of dysthymia (under the brand name Deniban). Amisulpride is a selective dopamine antagonist.
Amlexanox is an antiallergic drug, clinically effective for atopic diseases, especially allergic asthma and rhinitis. Amlexanox as a topical paste is a well tolerated treatment of recurrent aphthous ulcers. Recurrent aphthous ulcer (RAU) is the most prevalent oral mucosal disease in humans, estimated to affect between 5% and 50% of the general population.
Amlodipine is a long-acting calcium channel blocker used as an anti-hypertensive and in the treatment of angina. As other calcium channel blockers, amlodipine acts by relaxing the smooth muscle in the arterial wall, decreasing peripheral resistance and hence improving blood pressure; in angina it improves blood flow to the myocardium. It was developed under the direction of Dr. Simon Campbell; A long acting dihydropyridine calcium channel blocker. It is effective in the treatment of angina pectoris and hypertension; in angina it improves blood flow to the myocardium. Amlodipine (as besylate, mesylate or maleate) is a long-acting calcium channel blocker used as an anti hypertensive and in the treatment of angina. Amlodipine is marketed as Norvasc in North America and as Istin in the United Kingdom as well as under various other names. As other calcium channel blockers, amlodipine acts by relaxing the smooth muscle in the arterial wall, decreasing peripheral resistance and hence improving blood pressure; Amlodipine (as besylate, mesylate or maleate) is a long-acting calcium channel blocker used as an anti-hypertensive and in the treatment of angina. Amlodipine is marketed as Norvasc in North America and as Istin in the United Kingdom as well as under various other names. As other calcium channel blockers, amlodipine acts by relaxing the smooth muscle in the arterial wall, decreasing peripheral resistance and hence improving blood pressure; in angina it improves blood flow to the myocardium. It was developed under the direction of Dr. Simon Campbell.
Dextroamphetamine is only found in individuals that have used or taken this drug. It is the dextrorotary stereoisomer of the amphetamine molecule, which can take two different forms. It is a slightly polar, weak base and is lipophilic. The exact mechanism of action is not known. Dextroamphetamine stimulates the release of norepinephrine from central adrenergic receptors. At higher dosages, it causes release of dopamine from the mesocorticolimbic system and the nigrostriatal dopamine systems by reversal of the monoamine transporters. Dextroamphetamine may also act as a direct agonist on central 5-HT receptors and may inhibit monoamine oxidase (MAO). In the periphery, amphetamines are believed to cause the release of noradrenaline by acting on the adrenergic nerve terminals and alpha- and beta-receptors. Modulation of serotonergic pathways may contribute to the calming affect.
Anagrelide is only found in individuals that have used or taken this drug. It is a drug used for the treatment of essential thrombocytosis (ET; essential thrombocythemia). It also has been used in the treatment of chronic myeloid leukemia. [Wikipedia]The mechanism by which anagrelide reduces blood platelet count is still under investigation. Studies in patients support a hypothesis of dose-related reduction in platelet production resulting from a decrease in megakaryocyte hypermaturation. In blood withdrawn from normal volunteers treated with anagrelide, a disruption was found in the postmitotic phase of megakaryocyte development and a reduction in megakaryocyte size and ploidy. At therapeutic doses, anagrelide does not produce significant changes in white cell counts or coagulation parameters, and may have a small, but clinically insignificant effect on red cell parameters. Anagrelide inhibits cyclic AMP phosphodiesterase III (PDEIII). PDEIII inhibitors can also inhibit platelet aggregation. However, significant inhibition of platelet aggregation is observed only at doses of anagrelide higher than those required to reduce platelet count.
Anastrozole is a drug indicated in the treatment of breast cancer in post-menopausal women. It is used both in adjuvant therapy (i.e. following surgery) and in metastatic breast cancer. It decreases the amount of estrogens that the body makes. Anastrozole belongs in the class of drugs known as aromatase inhibitors. It inhibits the enzyme aromatase, which is responsible for converting androgens (produced by women in the adrenal glands) to estrogens.
Androsterone is an inactive breakdown metabolite of testosterone, the product of a reaction mediated by the enzyme oxidative 17beta-hydroxysteroid dehydrogenase (EC 1.1.1.51, 17beta-HSD). Androsterone can also be metabolized from other adrenal androgens such as dehydroepiandrosterone, dihydrotestosterone, or androstenedione, and is considered an inactive end product. However, it can be a physiological effector in its own right. Androsterone might be converted back to dihydrotestosterone. Humans (and other primates) are unique among mammals in having high levels of circulating androsterone glucuronide, a process that is the major role of uridine-diphospho-glucuronosyltransferase enzymes (EC 2.4.1.17, UGT) for glucuronidation of steroid metabolism in humans. Conjugation of androsterone is a pathway found in all vertebrates and it is widely recognized that the liver is a major site of glucuronidation. However, it is now clear that extrahepatic tissues are also involved in the conjugation of compounds to which these tissues are exposed. High levels of androsterone glucuronide found in the human prostate, breast cyst fluid, and ovary follicular fluid suggest that glucuronidation of 5alpha-reduced C19 steroids occurs in these tissues as well. In doping control, the ratio of androsterone/etiocholanolone provides valuable information that allows the assignment of a urine specimen to a particular person or the identification of urine samples with identical steroid profiles; this is particularly important to detect attempts of urine manipulation including urine alteration and substitution (PMID: 9188497, 17017935, 14643063, 12943709, 9699884, 17260133).
Aripiprazole is a warning has gone out recently because of this drug's name. The '-prazole' ending of this drug name makes this drug sound like it is one of the proton pump inhibitors (such as omeprazole, pantoprazole, lansoprazole) which are used in treating peptic ulcer disease. However, aripiprazole and these drugs are in an entirely different class of drugs altogether and confusing the two can lead to some unnecessary side effects. Aripiprazole is the sixth and most recent of the atypical antipsychotic medications to be approved by the Food and Drug Administration (FDA) for the treatment of schizophrenia. It has also recently received FDA approval for the treatment of acute manic and mixed episodes associated with bipolar disorder. Aripiprazole appears to mediate its antipsychotic effects primarily by partial agonism at the Dopamine 2 (D2)receptor.
Ascorbic acid is found naturally in citrus fruits and many vegetables and is an essential nutrient in human diets. It is necessary to maintain connective tissue and bone. The biologically active form of ascorbic acid is vitamin C. Vitamin C is a water soluble vitamin. Primates (including humans) and a few other species in all divisions of the animal kingdom, notably the guinea pig, have lost the ability to synthesize ascorbic acid and must obtain it in their food. Vitamin C functions as a reducing agent and coenzyme in several metabolic pathways. Vitamin C is considered an antioxidant (PubChem). Ascorbic acid is an electron donor for enzymes involved in collagen hydroxylation, biosynthesis of carnitine and norepinephrine, tyrosine metabolism, and amidation of peptide hormones. Ascrobic acid (vitamin C) deficiency causes scurvy. The amount of vitamin C necessary to prevent scurvy may not be adequate to maintain optimal health. The ability of vitamin C to donate electrons also makes it a potent water-soluble antioxidant that readily scavenges free radicals such as molecular oxygen, superoxide, hydroxyl radical, and hypochlorous acid. In this setting, several mechanisms could account for a link between vitamin C and heart disease. One is the relation between LDL oxidation and vitamins C and E. Vitamin C in vitro can recycle vitamin E, which can donate electrons to prevent LDL oxidation in vitro. As the lipid-phase vitamin E is oxidized, it can be regenerated by aqueous vitamin C. Other possibilities are that vitamin C could decrease cholesterol by mechanisms not well characterized, or could improve vasodilatation and vascular reactivity, perhaps by decreasing the interactions of nitric oxide with oxidants (PMID: 10799361). Moreover, ascorbic acid is found to be associated with hyperoxalemia, which is an inborn error of metabolism. Ascorbic acid is also a microbial metabolite produced by Ketogulonicigenium (PMID: 15785002).
Aspartylphenylalanine is a dipeptide composed of aspartate and phenylalanine, and is a metabolic byproduct of its methyl ester, aspartame (Nutrasweet). After hydrolysis of the ester bond in the intestinal lumen, the dipeptide is apparently absorbed and digested in the same manner as dipeptides derived from protein digestion. There are several Asp-Phe dipeptidases that degrade this peptide. It has been suggested that individuals with aspartame allergies may be deficient in this peptidase (PMID: 3743970). It has been observed that N-beta-aspartylphenylalanine (a breakdown product of Asp-Phe) is a naturally occurring peptide found in both blood and urine (PMID: 2723819).
Atomoxetine is the first non-stimulant drug approved for the treatment of attention-deficit hyperactivity disorder (ADHD). It is sold in the form of the hydrochloride salt of atomoxetine. This chemical is manufactured and marketed under the brand name Strattera; by Eli Lilly and Company and as a generic Attentin by Torrent Pharmaceuticals. There is currently no generic available within the United States due to patent restrictions. [Wikipedia]
Azelastine is only found in individuals that have used or taken this drug. It is a phthalazine derivative, and is an antihistamine and mast cell stabilizer available as a nasal spray for hay fever and as eye drops for allergic conjunctivitis.Azelastine competes with histamine for the H1-receptor sites on effector cells and acts as an antagonist by inhibiting the release of histamine and other mediators involved in the allergic response.
Benazepril, brand name Lotensin, is a medication used to treat high blood pressure (hypertension), congestive heart failure, and chronic renal failure. Upon cleavage of its ester group by the liver, benazepril is converted into its active form benazeprilat, a non-sulfhydryl angiotensin-converting enzyme (ACE) inhibitor.
Benzamide is an intermediate in the Benzoate degradation via CoA ligation. Benzamides are a class of chemical compounds derived from Benzamid, the carbonic acid amide of benzoic acid. In psychiatry some substituted benzamides are therapeutically used as neuroleptics and/or antipsychotics (wikipedia).
Benzoic acid, C6H5COOH, is a colourless crystalline solid and the simplest aromatic carboxylic acid. Benzoic acid occurs naturally free and bound as benzoic acid esters in many plant and animal species. Appreciable amounts have been found in most berries (around 0.05%). Cranberries contain as much as 300-1300 mg free benzoic acid per kg fruit. Benzoic acid is a fungistatic compound that is widely used as a food preservative. It often is conjugated to glycine in the liver and excreted as hippuric acid. Benzoic acid is a byproduct of phenylalanine metabolism in bacteria. It is also produced when gut bacteria process polyphenols (from ingested fruits or beverages). It can be found in Serratia (PMID:23061754).
Benzothiazole, also known as BT or benzosulfonazole, belongs to the class of organic compounds known as benzothiazoles. These are organic compounds containing a benzene fused to a thiazole ring (a five-membered ring with four carbon atoms, one nitrogen atom and one sulfur atom). This ring is a potential component in nonlinear optics (NLO). The nine atoms of the bicycle and the attached substituents are coplanar. Although the parent compound, benzothiazole is not widely used, many of its derivatives are found in commercial products or in nature. Benzothiazole is a coffee, cooked, and gasoline tasting compound. benzothiazole is found, on average, in the highest concentration in safflowers. benzothiazole has also been detected, but not quantified, in several different foods, such as common persimmons, fruits, guava, potato, and tea. This could make benzothiazole a potential biomarker for the consumption of these foods. Firefly luciferin can be considered a derivative of benzothiazole. The compound is used also used as an insecticide and food flavoring agent. Some drugs contain this group, examples being riluzole and pramipexole. It is colorless, slightly viscous liquid. It is a thermally stable electron-withdrawing moiety with numerous applications in dyes such as thioflavin. Benzothiazole is an aromatic heterocyclic compound with the chemical formula C7H5NS.
Benzphetamine is only found in individuals that have used or taken this drug. It is a sympathomimetic agent with properties similar to dextroamphetamine. It is used in the treatment of obesity. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1222)Although the mechanism of action of the sympathomimetic appetite suppressants in the treatment of obesity is not fully known, these medications have pharmacological effects similar to those of amphetamines. Amphetamine and related sympathomimetic medications (such as benzphetamine) are thought to stimulate the release of norepinephrine and/or dopamine from storage sites in nerve terminals in the lateral hypothalamic feeding center, thereby producing a decrease in appetite. This release is mediated by the binding of benzphetamine to centrally located adrenergic receptors.
Benzyl acetate, also known as benzyl ethanoate or fema 2135, belongs to the class of organic compounds known as benzyloxycarbonyls. These are organic compounds containing a carbonyl group substituted with a benzyloxyl group. Benzyl acetate is a sweet, apple, and apricot tasting compound. Benzyl acetate is found, on average, in the highest concentration within sweet basils. Benzyl acetate has also been detected, but not quantified, in several different foods, such as figs, fruits, pomes, tea, and alcoholic beverages. On high concnetrations benzyl acetate is a potentially toxic compound. If the compound has entered the eyes, they should be washed with large quantities of isotonic saline or water.
Betaxolol is only found in individuals that have used or taken this drug. It is a cardioselective beta-1-adrenergic antagonist with no partial agonist activity. [PubChem]Betaxolol selectively blocks catecholamine stimulation of beta(1)-adrenergic receptors in the heart and vascular smooth muscle. This results in a reduction of heart rate, cardiac output, systolic and diastolic blood pressure, and possibly reflex orthostatic hypotension. Betaxolol can also competitively block beta(2)-adrenergic responses in the bronchial and vascular smooth muscles, causing bronchospasm.
Bicalutamide is only found in individuals that have used or taken this drug. It is an oral non-steroidal anti-androgen for prostate cancer. It binds to the androgen receptor.Bicalutamide competes with androgen for the binding of androgen receptors, consequently blocking the action of androgens of adrenal and testicular origin which stimulate the growth of normal and malignant prostatic tissue.
Bifonazole is only found in individuals that have used or taken this drug. It is an azole antifungal drug. [Wikipedia]Bifonazole works by inhibiting the production of a substance called ergosterol, which is an essential component of fungal cell membranes.It acts to destabilize the fungal cyctochrome p450 51 enzyme (also known as Lanosterol 14-alpha demethylase). This is vital in the cell membrance structure of the fungus. Its inhibition leads to cell lysis. The disruption in production of ergosterol disrupts the cell membrane and causes holes to appear. The cell membranes of fungi are vital for their survival. They keep unwanted substances from entering the cells and stop the contents of the cells from leaking out. As bifonazole causes holes to appear in the cell membranes, essential constituents of the fungal cells can leak out. This kills the fungi.
Biliverdin is a green pigment formed as a byproduct of hemoglobin breakdown. It consists of four linearly connected pyrrole rings (a tetrapyrrole). Biliverdin is formed when the heme group in hemoglobin is cleaved at its alpha-methene bridge. The resulting biliverdin is then reduced to bilirubin, a yellow pigment, by the enzyme biliverdin reductase. The changing color of a bruise from deep purple to yellow over time is a graphical indicator of this reaction. Biliverdin occurs in the bile of amphibia and of birds, but not in normal human bile or serum.
Bisoprolol is a cardioselective &beta;1-adrenergic blocking agent used for secondary prevention of myocardial infarction (MI), heart failure, angina pectoris and mild to moderate hypertension. Bisoprolol is structurally similar to metoprolol, acebutolol and atenolol in that it has two substituents in the <i>para</i> position of the benzene ring. The &beta;1-selectivity of these agents is thought to be due in part to the large substituents in the <i>para</i> position. At lower doses (less than 20 mg daily), bisoprolol selectively blocks cardiac &beta;1-adrenergic receptors with little activity against &beta;2-adrenergic receptors of the lungs and vascular smooth muscle. Receptor selectivity decreases with daily doses of 20 mg or greater. Unlike propranolol and pindolol, bisoprolol does not exhibit membrane-stabilizing or sympathomimetic activity. Bisoprolol possesses a single chiral centre and is administered as a racemic mixture. Only <i>l</i>-bisoprolol exhibits significant &beta;-blocking activity.
Bromazepam is only found in individuals that have used or taken this drug. It is one of the benzodiazepines that is used in the treatment of anxiety disorders. [PubChem] It is a Schedule IV drug in the U.S. and Canada and under the Convention on Psychotropic Substances.Bromazepam binds to the GABA receptor GABA<sub>A</sub>, causing a conformational change and increasing inhibitory effects of GABA. Other neurotransmitters are not influenced.
Bupropion is a selective catecholamine (norepinephrine and dopamine) reuptake inhibitor. It has only a small effect on serotonin reuptake. It does not inhibit MAO. The antidepressant effect of bupropion is considered to be mediated by its dopaminergic and noradrenergic action. Bupropion has also been shown to act as a competitive alpha-3-beta-4- nicotinic antagonist, the alpha-3-beta-4-antagonism has been shown to interrupt addiction in studies of other drugs such as ibogaine. This alpha-3-beta-4-antagonism correlates quite well with the observed effect of interrupting addiction. A unicyclic, aminoketone antidepressant. The mechanism of its therapeutic actions is not well understood, but it does appear to block dopamine uptake. The hydrochloride is available as an aid to smoking cessation treatment; Bupropion is a selective catecholamine (norepinephrine and dopamine) reuptake inhibitor. It has only a small effect on serotonin reuptake. It does not inhibit MAO. The antidepressant effect of bupropion is considered to be mediated by its dopaminergic and noradrenergic action. Bupropion has also been shown to act as a competitive alpha-3-beta-4-nicotinic antagonist, the alpha-3-beta-4-antagonism has been shown to interrupt addiction in studies of other drugs such as ibogaine. This alpha-3-beta-4-antagonism correlates quite well with the observed effect of interrupting addiction. Bupropion (amfebutamone) (brand names Wellbutrin and Zyban) is an antidepressant of the aminoketone class, chemically unrelated to tricyclics or selective serotonin reuptake inhibitors (SSRIs). It is similar in structure to the stimulant cathinone, and to phenethylamines in general. It is a chemical derivative of diethylpropion, an amphetamine-like substance used as an anorectic. Bupropion is both a dopamine reuptake inhibitor and a norepinephrine reuptake inhibitor. It is often used as a smoking cessation aid.
N-Butyrylglycine is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism, such as ethylmalonic encephalopathy. In certain cases the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acyl glycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13), which is an enzyme that catalyzes the chemical reaction: acyl-CoA + glycine < -- > CoA + N-acylglycine amino acids composed of glycine substituted at the nitrogen rather than the usual carbon position, resulting in the loss of hydrogen bonding donors. Polymers of these compounds are called Peptoids.
Caffeic acid (CAS: 331-39-5) is a polyphenol present in normal human urine positively correlated to coffee consumption and influenced by the dietary intake of diverse types of food (PMID:16870009). Caffeic acid has been found to be a microbial metabolite of Escherichia (PMID: 28396925).
Camalexin is found in fats and oils. Camalexin is an alkaloid from the leaves of Camelina sativa (false flax) infected by the fungus Alternaria brassica
L-Canavanine, a non-protein amino acid of certain leguminous plants, is related structurally to the protein amino acid, L-arginine. Canavanine is accumulated primarily in the seeds where it serves both as a defensive compound against herbivores and a vital source of nitrogen for the growing embryo. Organisms that consume it can mistakenly incorporate it into their own proteins, in the place of arginine thereby producing structurally aberrant proteins that may not function properly or not at all. Some specialized herbivores tolerate L-canavanine either because they metabolize it efficiently or avoid its incorporation into their own nascent proteins.
An anticonvulsant used to control grand mal and psychomotor or focal seizures. Its mode of action is not fully understood, but some of its actions resemble those of phenytoin; although there is little chemical resemblance between the two compounds, their three-dimensional structure is similar. [PubChem]
Carboxy-ibuprofen is a metabolite of ibuprofen. Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) used for relief of symptoms of arthritis, fever, as an analgesic (pain reliever), especially where there is an inflammatory component, and dysmenorrhea. Ibuprofen is known to have an antiplatelet effect, though it is relatively mild and somewhat short-lived when compared with aspirin or other better-known antiplatelet drugs. (Wikipedia)
Carvedilol is only found in individuals that have used or taken this drug. It is a non-selective beta blocker indicated in the treatment of mild to moderate congestive heart failure (CHF).Carvedilol is a racemic mixture in which nonselective beta-adrenoreceptor blocking activity is present in the S(-) enantiomer and alpha-adrenergic blocking activity is present in both R(+) and S(-) enantiomers at equal potency. Carvedilol's beta-adrenergic receptor blocking ability decreases the heart rate, myocardial contractility, and myocardial oxygen demand. Carvedilol also decreases systemic vascular resistance via its alpha adrenergic receptor blocking properties. Carvedilol and its metabolite BM-910228 (a less potent beta blocker, but more potent antioxidant) have been shown to restore the inotropic responsiveness to Ca<sup>2+</sup> in OH<sup>-</sup> free radical-treated myocardium. Carvedilol and its metabolites also prevent OH<sup>-</sup> radical-induced decrease in sarcoplasmic reticulum Ca<sup>2+</sup>-ATPase activity. Therefore, carvedilol and its metabolites may be beneficial in chronic heart failure by preventing free radical damage.
Catechin, also known as cyanidanol or catechuic acid, belongs to the class of organic compounds known as catechins. Catechins are compounds containing a catechin moiety, which is a 3,4-dihydro-2-chromene-3,5.7-tiol. Catechin also belongs to the group of compounds known as flavan-3-ols (or simply flavanols), part of the chemical family of flavonoids. Catechin is one of the 4 catechin known diastereoisomers. Two of the isomers are in trans configuration and are called catechin and the other two are in cis configuration and are called epicatechin. The most common catechin isomer is the (+)-catechin. The other stereoisomer is (-)-catechin or ent-catechin. The most common epicatechin isomer is (-)-epicatechin. Catechin is a very hydrophobic molecule, practically insoluble (in water), and relatively neutral. Catechin is a bitter tasting compound and is associated with the bitterness in tea. Catechin is a plant secondary metabolite. Secondary metabolites are metabolically or physiologically non-essential metabolites that may serve a role as defense or signalling molecules. In some cases they are simply molecules that arise from the incomplete metabolism of other secondary metabolites. Catechin is an antioxidant flavonoid, occurring especially in woody plants as both Catechin and (-)-Catechin (cis) forms. Outside of the human body, Catechin is found, on average, in the highest concentration in foods, such as blackcurrants (Ribes nigrum), evergreen blackberries (Rubus laciniatus), and blackberries (Rubus) and in a lower concentration in dills (Anethum graveolens), hot chocolates, and medlars (Mespilus germanica). Catechin has also been detected, but not quantified in, several different foods, such as rice (Oryza sativa), apple ciders, peanuts (Arachis hypogaea), fruit juices, and red teas. This could make catechin a potential biomarker for the consumption of these foods. Based on a literature review a significant number of articles have been published on Catechin.
Cefaclor is only found in individuals that have used or taken this drug. It is a semisynthetic, broad-spectrum antibiotic derivative of cephalexin. [PubChem]Cefaclor, like the penicillins, is a beta-lactam antibiotic. By binding to specific penicillin-binding proteins (PBPs) located inside the bacterial cell wall, it inhibits the third and last stage of bacterial cell wall synthesis. Cell lysis is then mediated by bacterial cell wall autolytic enzymes such as autolysins. It is possible that cefaclor interferes with an autolysin inhibitor.
Cefdinir (marketed by Abbott Laboratories under the brand name Omnicef) is a semi-synthetic, broad-spectrum antibiotic in the third generation of the cephalosporin class, proven effective for common bacterial infections of the ear, sinus, throat, and skin. It was approved by the U.S. Food and Drug Administration (FDA) in December of 1997.
Cefixime, an antibiotic, is a third-generation cephalosporin like ceftriaxone and cefotaxime. Cefixime is highly stable in the presence of beta-lactamase enzymes. As a result, many organisms resistant to penicillins and some cephalosporins due to the presence of beta-lactamases, may be susceptible to cefixime. The antibacterial effect of cefixime results from inhibition of mucopeptide synthesis in the bacterial cell wall.
Guanosine cyclic 3',5'-(hydrogen phosphate). A guanine nucleotide containing one phosphate group which is esterified to the sugar moiety in both the 3'- and 5'-positions. It is a cellular regulatory agent and has been described as a second messenger. Its levels increase in response to a variety of hormones, including acetylcholine, insulin, and oxytocin and it has been found to activate specific protein kinases. (From Merck Index, 11th ed).
Chlorogenic acid is an ester of caffeic acid and quinic acid. Chlorogenic acid is the major polyphenolic compound in coffee, isolated from the leaves and fruits of dicotyledonous plants. This compound, long known as an antioxidant, also slows the release of glucose into the bloodstream after a meal. Coffee is a complex mixture of chemicals that provides significant amounts of chlorogenic acid. The chlorogenic acid content of a 200 ml (7-oz) cup of coffee has been reported to range from 70-350 mg, which would provide about 35-175 mg of caffeic acid. The results of epidemiological research suggest that coffee consumption may help prevent several chronic diseases, including type 2 diabetes mellitus, Parkinson's disease and liver disease (cirrhosis and hepatocellular carcinoma). Most prospective cohort studies have not found coffee consumption to be associated with significantly increased cardiovascular disease risk. However, coffee consumption is associated with increases in several cardiovascular disease risk factors, including blood pressure and plasma homocysteine. At present, there is little evidence that coffee consumption increases the risk of cancer. (PMID:16507475, 17368041).
Chlorpheniramine is a histamine H1 antagonist used in allergic reactions, hay fever, rhinitis, urticaria, and asthma. It has also been used in veterinary applications. One of the most widely used of the classical antihistaminics, it generally causes less drowsiness and sedation than Promethazine. -- Pubchem; Chlorphenamine or chlorpheniramine, commonly marketed as its salt chlorphenamine maleate (Chlor- Trimeton, Piriton, Chlor- Tripolon), is a first generation antihistamine used in the prevention of the symptoms of allergic conditions such as rhinitis and urticaria.- wikipedia.
A renal dehydropeptidase-I and leukotriene D4 dipeptidase inhibitor. Since the antibiotic, imipenem, is hydrolyzed by dehydropeptidase-I, which resides in the brush border of the renal tubule, cilastatin is administered with imipenem to increase its effectiveness. The drug also inhibits the metabolism of leukotriene D4 to leukotriene E4. [PubChem]
Citalopram is an antidepressant drug used to treat depression associated with mood disorders. It is also used on occasion in the treatment of body dysmorphic disorder and anxiety; Citalopram belongs to a class of drugs known as selective serotonin reuptake inhibitors (SSRIs). It is sold under the brand-names Celexa (U.S., Forest Laboratories, Inc.), Cipramil, Seropram (Europe and Australia) and Ciazil (Australia); A furancarbonitrile that is one of the serotonin uptake inhibitors used as an antidepressant. The drug is also effective in reducing ethanol uptake in alcoholics and is used in depressed patients who also suffer from tardive dyskinesia in preference to tricyclic antidepressants, which aggravate this condition; Citalopram is an antidepressant drug used to treat depression associated with mood disorders. It is also used on occasion in the treatment of body dysmorphic disorder and anxiety. Citalopram belongs to a class of drugs known as selective serotonin reuptake inhibitors (SSRIs).
Cladribine is only found in individuals that have used or taken this drug. It is an antineoplastic agent used in the treatment of lymphoproliferative diseases including hairy-cell leukemia. [PubChem]Cladribine is structurally related to fludarabine and pentostatin but has a different mechanism of action. Although the exact mechanism of action has not been fully determined, evidence shows that cladribine is phosphorylated by deoxycytidine kinase to the nucleotidecladribine triphosphate (CdATP; 2-chloro-2â€²-deoxyadenosine 5â€²-triphosphate), which accumulates and is incorporated into DNA in cells such as lymphocytes that contain high levels of deoxycytidine kinase and low levels of deoxynucleotidase, resulting in DNA strand breakage and inhibition of DNA synthesis and repair. High levels of CdATP also appear to inhibit ribonucleotide reductase, which leads to an imbalance in triphosphorylated deoxynucleotide (dNTP) pools and subsequent DNA strand breaks, inhibition of DNA synthesis and repair, nicotinamide adenine dinucleotide (NAD) and ATP depletion, and cell death. Unlike other antimetabolite drugs, cladribine has cytotoxic effects on resting as well as proliferating lymphocytes. However, it does cause cells to accumulate at the G1/S phase junction, suggesting that cytotoxicity is associated with events critical to cell entry into S phase. It also binds purine nucleoside phosphorylase (PNP), however no relationship between this binding and a mechanism of action has been established.
Clarithromycin, a semisynthetic macrolide antibiotic derived from erythromycin, inhibits bacterial protein synthesis by binding to the bacterial 50S ribosomal subunit. Binding inhibits peptidyl transferase activity and interferes with amino acid translocation during the translation and protein assembly process. Clarithromycin may be bacteriostatic or bactericidal depending on the organism and drug concentration.
A fat-soluble riminophenazine dye used for the treatment of leprosy. It has been used investigationally in combination with other antimycobacterial drugs to treat Mycobacterium avium infections in AIDS patients. Clofazimine also has a marked anti-inflammatory effect and is given to control the leprosy reaction, erythema nodosum leprosum. (From AMA Drug Evaluations Annual, 1993, p1619)
Clomipramine, the 3-chloro analog of imipramine, is a dibenzazepine-derivative tricyclic antidepressant (TCA). TCAs are structurally similar to phenothiazines. They contain a tricyclic ring system with an alkyl amine substituent on the central ring. In non-depressed individuals, clomipramine does not affect mood or arousal, but may cause sedation. In depressed individuals, clomipramine exerts a positive effect on mood. TCAs are potent inhibitors of serotonin and norepinephrine reuptake. Tertiary amine TCAs, such as clomipramine, are more potent inhibitors of serotonin reuptake than secondary amine TCAs, such as nortriptyline and desipramine. TCAs also down-regulate cerebral cortical &beta;-adrenergic receptors and sensitize post-synaptic serotonergic receptors with chronic use. The antidepressant effects of TCAs are thought to be due to an overall increase in serotonergic neurotransmission. TCAs also block histamine-H<sub>1</sub> receptors, &alpha;<sub>1</sub>-adrenergic receptors and muscarinic receptors, which accounts for their sedative, hypotensive and anticholinergic effects (e.g. blurred vision, dry mouth, constipation, urinary retention), respectively. See toxicity section below for a complete listing of side effects. Clomipramine may be used to treat obsessive-compulsive disorder and disorders with an obsessive-compulsive component (e.g. depression, schizophrenia, Tourette's disorder). Unlabeled indications include panic disorder, chronic pain (e.g. central pain, idiopathic pain disorder, tension headache, diabetic peripheral neuropathy, neuropathic pain), cataplexy and associated narcolepsy, autistic disorder, trichotillomania, onchophagia, stuttering, premature ejaculation, and premenstrual syndrome. Clomipramine is rapidly absorbed from the gastrointestinal tract and demethylated in the liver to its primary active metabolite, desmethylclomipramine.
Clonidine, an imidazoline-derivative hypotensive agent is a centrally-acting &alpha;<sub>2</sub>-adrenergic agonist. It crosses the blood-brain barrier and acts in the hypothalamus to induce a decrease in blood pressure. It may also be administered as an epidural infusion as an adjunct treatment in the management of severe cancer pain that is not relieved by opiate analgesics alone. Clonidine may be used for differential diagnosis of pheochromocytoma in hypertensive patients. Other uses for clonidine include prophylaxis of vascular migraine headaches, treatment of severe dysmenorrhea, management of vasomotor symptoms associated with menopause, rapid detoxification in the management of opiate withdrawal, treatment of alcohol withdrawal used in conjunction with benzodiazepines, management of nicotine dependence, topical use to reduce intraocular pressure in the treatment of open-angle and secondary glaucoma and hemorrhagic glaucoma associated with hypertension, and in the treatment of attention-deficit hyperactivity disorder (ADHD). Clonidine also exhibits some peripheral activity.
Coniferaldehyde (CAS: 458-36-6), also known as 4-hydroxy-3-methoxycinnamaldehyde or ferulaldehyde, belongs to the class of organic compounds known as methoxyphenols. Methoxyphenols are compounds containing a methoxy group attached to the benzene ring of a phenol moiety. Coniferaldehyde is an extremely weak basic (essentially neutral) compound (based on its pKa). Outside of the human body, coniferaldehyde is found, on average, in the highest concentration within sherries. Coniferaldehyde has also been detected, but not quantified in, several different foods, such as highbush blueberries, lima beans, Chinese cabbages, loquats, and greenthread tea. This could make coniferaldehyde a potential biomarker for the consumption of these foods. BioTransformer predicts that coniferaldehyde is a product of caffeic aldehyde metabolism via a catechol-O-methylation-pattern2 reaction catalyzed by the enzyme catechol O-methyltransferase (PMID: 30612223).
Corticosterone, also known as 17-deoxycortisol, belongs to the class of organic compounds known as 21-hydroxysteroids. These are steroids carrying a hydroxyl group at the 21-position of the steroid backbone. Thus, corticosterone is considered to be a steroid lipid molecule. Corticosterone is a very hydrophobic molecule, practically insoluble in water, and relatively neutral. In many species, including amphibians, reptiles, rodents and birds, corticosterone is a main glucocorticoid,[3] involved in regulation of energy, immune reactions, and stress responses. Corticosterone is the precursor molecule to the mineralocorticoid aldosterone, one of the major homeostatic modulators of sodium and potassium levels in vivo.
Cortisone is a naturally occurring glucocorticoid. It has been used in replacement therapy for adrenal insufficiency and as an anti-inflammatory agent. Cortisone itself is inactive. It is converted in the liver into the active metabolite cortisol. Cortisone is a corticosteroid hormone released by the adrenal gland in response to stress. One of cortisone's effects on the body, and a potentially harmful side effect when administered clinically, is the suppression of the immune system. This is an explanation for the apparent correlation between high stress and sickness.
Creatinine, or creatine anhydride, is a breakdown product of creatine phosphate in muscle. The loss of a water molecule from creatine results in the formation of creatinine. Creatinine is transferred to the kidneys by blood plasma, whereupon it is eliminated from the body by glomerular filtration and partial tubular excretion. Creatinine is usually produced at a fairly constant rate by the body. Measuring serum creatinine is a simple test and it is the most commonly used indicator of renal function. A rise in blood creatinine levels is observed only with marked damage to functioning nephrons. Therefore, this test is not suitable for detecting early kidney disease. The typical reference range for women is considered about 45-90 µmol/L; for men 60-110 µmol/L. Creatine and creatinine are metabolized in the kidneys, muscle, liver, and pancreas.
Cytarabine, or cytosine arabinoside, a pyrimidine nucleoside analog, is found in mushrooms. Cytarabine is isolated from the mushroom Xerocomus nigromaculatus of unknown palatability. Cytarabine is an antineoplastic anti-metabolite used in the treatment of several forms of leukemia including acute myelogenous leukemia and meningeal leukemia. Cytarabine is an antimetabolite antineoplastic agent that inhibits the synthesis of DNA. Its actions are specific for the S phase of the cell cycle to stop normal cell development and division. Cytarabine is metabolized intracellularly into its active triphosphate form (cytosine arabinoside triphosphate). This metabolite then damages DNA by multiple mechanisms, including the inhibition of alpha-DNA polymerase, inhibition of DNA repair through an effect on beta-DNA polymerase, and incorporation into DNA. The latter mechanism is probably the most important. Cytotoxicity is highly specific for the S phase of the cell cycle. Cytarabine is a chemotherapy agent used mainly in the treatment of hematological malignancies such as acute myeloid leukemia (AML) and non-Hodgkin lymphoma. It is also known as ara C. Cytosine arabinoside is an antimetabolic agent with the chemical name of 1 -arabinofuranosylcytosine. Its mode of action is due to its rapid conversion into cytosine arabinoside triphosphate, which damages DNA when the cell cycle holds in the S phase (synthesis of DNA). Rapidly dividing cells, which require DNA replication for mitosis, are therefore most affected. Cytosine arabinoside also inhibits both DNA and RNA polymerases and nucleotide reductase enzymes needed for DNA synthesis
L,L-Cyclo(leucylprolyl) is found in alcoholic beverages. L,L-Cyclo(leucylprolyl) is produced by microorganisms and is a bitter component of sake and contributes to the flavour of beer.
Cyclohexylamine is a food contaminant arising from its use as a boiler water additive Cyclohexylamine, also called hexahydroaniline, 1-aminocyclohexane, or aminohexahydrobenzene, is an organic chemical, an amine derived from cyclohexane. It is a clear to yellowish liquid with fishy odor, with melting point of 17.7 ¬∞C and boiling point 134.5 ¬∞C, miscible with water. Like other amines, it is of mildly alkaline nature, compared to strong bases such as NaOH, but it is a stronger base than its aromatic sister compound aniline, which differs only in that its ring is aromatic. It is flammable, with flash point at 28.6 ¬∞C. Explosive mixtures with air can be formed above 26 ¬∞C. It is toxic by both ingestion and inhalation; the inhalation itself may be fatal. It readily absorbs through skin, which it irritates. It is corrosive. Cyclohexylamine is listed as an extremely hazardous substance as defined by Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act
Cyproheptadine is only found in individuals that have used or taken this drug. It is a serotonin antagonist and a histamine H1 blocker used as antipruritic, appetite stimulant, antiallergic, and for the post-gastrectomy dumping syndrome, etc. [PubChem]Cyproheptadine competes with free histamine for binding at HA-receptor sites. This antagonizes the effects of histamine on HA-receptors, leading to a reduction of the negative symptoms brought on by histamine HA-receptor binding. Cyproheptadine also competes with serotonin at receptor sites in smooth muscle in the intestines and other locations. Antagonism of serotonin on the appetite center of the hypothalamus may account for Cyproheptadine's ability to stimulate appetite.
Cystathionine is a dipeptide formed by serine and homocysteine. Cystathioninuria is a prominent manifestation of vitamin-B6 deficiency. The transsulfuration of methionine yields homocysteine, which combines with serine to form cystathionine, the proximate precursor of cysteine through the enzymatic activity of cystathionase. In conditions in which cystathionine gamma-synthase or cystathionase is deficient, for example, there is cystathioninuria. Although cystathionine has not been detected in normal human serum or plasma by most conventional methods, gas chromatographic/mass spectrometric methodology detected a mean concentration of cystathionine in normal human serum of 140 nM, with a range of 65 to 301 nM. Cystathionine concentrations in CSF have been 10, 1, and 0.5 uM, and "not detected". Only traces (i.e., <1 uM) of cystathionine are present in normal CSF.587. Gamma-cystathionase deficiency (also known as Cystathioninuria), which is an autosomal recessive disorder (NIH: 2428), provided the first instance in which, in a human, the major biochemical abnormality due to a defined enzyme defect was clearly shown to be alleviated by administration of large doses of pyridoxine. The response in gamma-cystathionase-deficient patients is not attributable to correction of a preexisting deficiency of this vitamin (OMMBID, Chap. 88).
Cysteinesulfonic acid, also known as (2r)-2-amino-3-sulfopropanoic acid or 3-sulfoalanine, is a member of the class of compounds known as L-alpha-amino acids. L-alpha-amino acids are alpha amino acids which have the L-configuration of the alpha-carbon atom. Cysteinesulfonic acid is soluble (in water) and an extremely strong acidic compound (based on its pKa). Cysteinesulfonic acid can be found in a number of food items such as roman camomile, pili nut, chicory, and garden tomato, which makes cysteinesulfonic acid a potential biomarker for the consumption of these food products.
Cytidine is a nucleoside that is composed of the base cytosine linked to the five-carbon sugar D-ribose. Cytidine is a pyrimidine that besides being incorporated into nucleic acids, can serve as a substrate for the salvage pathway of pyrimidine nucleotide synthesis. It is a precursor of cytidine triphosphate (CTP) needed in the phosphatidylcholine (PC) and phosphatidylethanolamine (PE) biosynthetic pathways. These variations probably reflect the species differences in cytidine deaminase, the enzyme that converts cytidine to uridine in the body. The transport of cytidine into the brain's extracellular fluid, and then into neurons and glia, are essential prerequisites for cytidine to be utilized in the brain. An efficient mechanism mediating the brain uptake of circulating cytidine has not yet been demonstrated. The biosynthesis of PC, the most abundant phosphatide in the brain, via the Kennedy pathway requires phosphocholine and cytidine triphosphate (CTP), a cytidine nucleotide involved in the rate-limiting step. The enzyme that converts CTP to endogenous CDP-choline (CTP:phosphocholine cytidylyltransferase) is unsaturated at physiological brain CTP levels. APOBEC is a family of enzymes that has been discovered with the ability to deaminate cytidines on RNA or DNA. The human apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3G protein (APOBEC3G, or hA3G), provides cells with an intracellular antiretroviral activity that is associated with the hypermutation of viral DNA through cytidine deamination. Indeed, hA3G belongs to a family of vertebrate proteins that contains one or two copies of a signature sequence motif unique to cytidine deaminases (CTDAs) (PMID: 16769123, 15780864, 16720547).
Cytosine, also known as C, belongs to the class of organic compounds known as pyrimidones. Pyrimidones are compounds that contain a pyrimidine ring, which bears a ketone. Pyrimidine is a 6-membered ring consisting of four carbon atoms and two nitrogen centers at the 1- and 3- ring positions. Cytosine is also classified as a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached (an amine group at position 4 and a keto group at position 2). Cytosine is one of the four main bases found in DNA and RNA, along with adenine, guanine, and thymine (uracil in RNA). The nucleoside of cytosine is cytidine. In Watson-Crick base pairing, cytosine forms three hydrogen bonds with guanine. Cytosine was discovered and named by Albrecht Kossel and Albert Neumann in 1894 when it was hydrolyzed from calf thymus tissues. Cytosine exists in all living species, ranging from bacteria to plants to humans. Within cells, cytosine can undergo several enzymatic reactions. It can be methylated into 5-methylcytosine by an enzyme called DNA methyltransferase (DNMT) or be methylated and hydroxylated to make 5-hydroxymethylcytosine. The DNA methyltransferase (DNMT) family of enzymes transfer a methyl group from S-adenosyl-l-methionine (SAM) to the 5‚Äô carbon of cytosine in a molecule of DNA. High levels of cytosine can be found in the urine of individuals with severe combined immunodeficiency syndrome (SCID). Cytosine concentrations as high as (23-160 mmol/mol creatinine) were detected in SCID patients compared to normal levels of <2 mmol/mol creatinine (PMID: 262183).
A compound composed of a two cyclic peptides attached to a phenoxazine that is derived from streptomyces parvullus. It binds to DNA and inhibits RNA synthesis (transcription), with chain elongation more sensitive than initiation, termination, or release. As a result of impaired mRNA production, protein synthesis also declines after dactinomycin therapy. (From AMA Drug Evaluations Annual, 1993, p2015)
Daidzein is one of several known isoflavones. Isoflavones compounds are found in a number of plants, but soybeans and soy products like tofu and textured vegetable protein are the primary food source. Up until recently, daidzein was considered to be one of the most important and most studied isoflavones, however more recently attention has shifted to isoflavone metabolites. Equol represents the main active product of daidzein metabolism, produced via specific microflora in the gut. The clinical effectiveness of soy isoflavones may be a function of the ability to biotransform soy isoflavones to the more potent estrogenic metabolite, equol, which may enhance the actions of soy isoflavones, owing to its greater affinity for estrogen receptors, unique antiandrogenic properties, and superior antioxidant activity. However, not all individuals consuming daidzein produce equol. Only approximately one-third to one-half of the population is able to metabolize daidzein to equol. This high variability in equol production is presumably attributable to interindividual differences in the composition of the intestinal microflora, which may play an important role in the mechanisms of action of isoflavones. But, the specific bacterial species in the colon involved in the production of equol are yet to be discovered. (PMID:18045128, 17579894). Daidzein is a biomarker for the consumption of soy beans and other soy products.
Decanal, also known as 1-decyl aldehyde or capraldehyde, belongs to the class of organic compounds known as medium-chain aldehydes. These are an aldehyde with a chain length containing between 6 and 12 carbon atoms. Thus, decanal is considered to be a fatty aldehyde lipid molecule. Decanal is a very hydrophobic molecule, practically insoluble in water, and relatively neutral. Decanal exists in all eukaryotes, ranging from yeast to humans. Decanal is a sweet, aldehydic, and citrus tasting compound. Decanal is found, on average, in the highest concentration within a few different foods, such as corianders, dills, and gingers and in a lower concentration in limes, sweet oranges, and safflowers. Decanal has also been detected, but not quantified, in several different foods, such as fishes, cauliflowers, citrus, fats and oils, and lemon grass. This could make decanal a potential biomarker for the consumption of these foods. Decanal is a potentially toxic compound. Decanal, with regard to humans, has been found to be associated with several diseases such as uremia, asthma, and perillyl alcohol administration for cancer treatment; decanal has also been linked to the inborn metabolic disorder celiac disease. Decanal occurs naturally and is used in fragrances and flavoring. Chronic exposure of uremic toxins can lead to a number of conditions including renal damage, chronic kidney disease and cardiovascular disease. Uremic toxins tend to accumulate in the blood either through dietary excess or through poor filtration by the kidneys.
Dehydroepiandrosterone (DHEA) is a natural steroid hormone produced from cholesterol by the adrenal glands. DHEA is also produced in the gonads, adipose tissue, and the brain. DHEA is structurally similar to and is a precursor of, androstenedione, testosterone, estradiol, estrone, and estrogen. It is the most abundant hormone in the human body. Most of DHEA is sulfated (dehydroepiandrosterone sulfate or DHEA-S) before secretion. DHEA-S is the sulfated version of DHEA; this conversion is reversibly catalyzed by sulfotransferase (SULT2A1) primarily in the adrenals, the liver, and small intestines. In blood, most DHEA is found as DHEA-S with levels that are about 300 times higher than free DHEA. Blood measurements of DHEA-S/DHEA are useful to detect excess adrenal activity as seen in adrenal cancer or hyperplasia, including certain forms of congenital adrenal hyperplasia. Women with polycystic ovary syndrome tend to have normal or mildly elevated levels of DHEA-S.
5-Hydroxylysine (Hyl), also known as hydroxylysine or 5-Hydroxy-L-lysine, belongs to the class of organic compounds known as L-alpha-amino acids. These are alpha amino acids which have the L-configuration of the alpha-carbon atom. Amino acids are organic compounds that contain amino (‚ÄìNH2) and carboxyl (‚ÄìCOOH) functional groups, along with a side chain (R group) specific to each amino acid. 5-Hydroxylysine is a hydroxylated derivative of the amino acid lysine that is present in certain collagens, the chief structural protein of mammalian skin and connective tissue. 5-Hydroxylysine arises from a post-translational hydroxy modification of lysine and is biosynthesized from lysine via oxidation by lysyl hydroxylase enzymes. 5-Hydroxylysine can then undergo further modification by glycosylation, giving rise to galactosyl hydroxylysine (GH) and glucosylgalactosyl hydroxylysine (GGH). These glycosylated forms of hydroxylysine contribute to collagen‚Äôs unusual toughness and resiliency. The monoglycosylated, galactosyl-hydroxylysine is enriched in bone compared with the disaccharide form, glucosyl-galactosyl-hydroxylysine, which is the major form in skin. 5-Hydroxylysine exists in all eukaryotes, ranging from yeast to humans. It was first discovered in 1921 by Donald Van Slyke. Free forms of hydroxylysine arise through proteolytic degradation of collagen.  Urinary excretion of 5-Hydroxylysine and its glycosides can be used as an index of collagen degradation, with high levels being indicative of more rapid or extensive collagen degradation (often seen in patients with thermal burns, Paget's disease of bone or hyperphosphatasia) (PMID: 404321).
Deoxycytidine monophosphate (dCMP), also known as deoxycytidylic acid or deoxycytidylate in its conjugate acid and conjugate base forms, respectively, is a deoxynucleotide, and one of the four monomers that make up DNA. In a DNA double helix, it will base pair with deoxyguanosine monophosphate. dCMP belongs to the class of organic compounds known as pyrimidine 2'-deoxyribonucleoside monophosphates. These are pyrimidine nucleotides with a monophosphate group linked to the ribose moiety lacking a hydroxyl group at position 2. Deficiency of the enzyme deoxycytidine kinase (EC2.7.1.74) is associated with resistance to antiviral and anticancer chemotherapeutic agents, whereas increased enzyme activity is associated with increased activation of these compounds to cytotoxic nucleoside triphosphate derivatives. dCMP exists in all living species, ranging from bacteria to humans. Within humans, dCMP participates in a number of enzymatic reactions. In particular, dCMP can be converted to dCDP by the enzyme UMP-CMP kinase 2. In addition, dCMP can be converted into deoxycytidine, which is catalyzed by the enzyme cytosolic purine 5'-nucleotidase. In humans, dCMP is involved in the metabolic disorder called ump synthase deficiency (orotic aciduria). Outside of the human body, dCMP has been detected, but not quantified in several different foods, such as turnips, garlics, agaves, garden onions, and italian sweet red peppers. dCMP is a deoxycytosine nucleotide containing one phosphate group esterified to the deoxyribose moiety in the 2'-,3'- or 5- positions.
Deoxyuridine monophosphate (dUMP), also known as deoxyuridylic acid or deoxyuridylate in its conjugate acid and conjugate base forms, respectively, is a deoxynucleotide. It belongs to the class of organic compounds known as pyrimidine 2'-deoxyribonucleoside monophosphates. These are pyrimidine nucleotides with a monophosphate group linked to the ribose moiety lacking a hydroxyl group at position 2. dUMP exists in all living species, ranging from bacteria to humans. Within humans, dUMP participates in a number of enzymatic reactions. In particular, dUMP can be biosynthesized from dCMP through its interaction with the enzyme deoxycytidylate deaminase. In addition, dUMP can be biosynthesized from deoxyuridine; which is mediated by the enzyme thymidine kinase, cytosolic. In humans, dUMP is involved in pyrimidine metabolism. A pyrimidine 2'-deoxyribonucleoside 5'-monophosphate having uracil as the nucleobase. Outside of the human body, dUMP has been detected, but not quantified in several different foods, such as breadnut tree seeds, sea-buckthornberries, sour cherries, black walnuts, and common oregano.
Desloratadine is a second generation, tricyclic antihistamine that which has a selective and peripheral H1-antagonist action. It is the active descarboethoxy metabolite of loratidine (a second generation histamine). Desloratidine has a long-lasting effect and does not cause drowsiness because it does not readily enter the central nervous system.
Desoximetasone is only found in individuals that have used or taken this drug. It is a topical anti-inflammatory glucocorticoid used in dermatoses, skin allergies, psoriasis, etc. [PubChem]The precise mechanism of the antiinflammatory activity of topical steroids in the treatment of steroid-responsive dermatoses, in general, is uncertain. However, corticosteroids are thought to act by the induction of phospholipase A<sub>2</sub> inhibitory proteins, collectively called lipocortins. This is achieved first by the drug binding to the glucocorticoid receptors which then translocates into the nucleus and binds to DNA causing various activations and repressions of genes. It is postulated that these proteins control the biosynthesis of potent mediators of inflammation such as prostaglandins and leukotrienes by inhibiting the release of their common precursor arachidonic acid. Arachidonic acid is released from membrane phospholipids by phospholipase A<sub>2</sub>.
Dexbrompheniramine is only found in individuals that have used or taken this drug. It is an antihistamine used to treat allergic conditions such as hay fever or urticaria. Dexbrompheniramine competitively binds to the histamine H<sub>1</sub>-receptor. It competes with histamine for the normal H<sub>1</sub>-receptor sites on effector cells of the gastrointestinal tract, blood vessels and respiratory tract. This blocks the action of endogenous histamine, which subsequently leads to temporary relief of the negative symptoms brought on by histamine.
Dexchlorpheniramine is the S-enantiomer of chlorphenamine (chloropheniramine) and is a first-generation alkylamine H1-antihistamine.
Dextrorphan is a metabolite of Dextromethorphan. Dextrorphan (DXO) is a psychoactive drug of the morphinan chemical class which acts as an antitussive or cough suppressant and dissociative hallucinogen. It is the dextro-stereoisomer of racemorphan, the levo-half being levorphanol. Dextrorphan is produced by O-demethylation of dextromethorphan by CYP2D6. Dextrorphan is an NMDA antagonist and contributes to the psychoactive effects of dextromethorphan. (Wikipedia)
Diazepam is a benzodiazepine with anticonvulsant, anxiolytic, sedative, muscle relaxant, and amnesic properties and a long duration of action. Its actions are mediated by enhancement of gamma-aminobutyric acid activity. It is used in the treatment of severe anxiety disorders, as a hypnotic in the short-term management of insomnia, as a sedative and premedicant, as an anticonvulsant, and in the management of alcohol withdrawal syndrome. (From Martindale, The Extra Pharmacopoeia, 30th ed, p589).
Diazoxide is only found in individuals that have used or taken this drug. It is a benzothiadiazine derivative that is a peripheral vasodilator used for hypertensive emergencies. It lacks diuretic effect, apparently because it lacks a sulfonamide group. [PubChem]As a diuretic, diazoxide inhibits active chloride reabsorption at the early distal tubule via the Na-Cl cotransporter, resulting in an increase in the excretion of sodium, chloride, and water. Thiazides like diazoxide also inhibit sodium ion transport across the renal tubular epithelium through binding to the thiazide sensitive sodium-chloride transporter. This results in an increase in potassium excretion via the sodium-potassium exchange mechanism. The antihypertensive mechanism of diazoxide is less well understood although it may be mediated through its action on carbonic anhydrases in the smooth muscle or through its action on the large-conductance calcium-activated potassium (KCa) channel, also found in the smooth muscle. As a antihypoglycemic, diazoxide inhibits insulin release from the pancreas, probably by opening potassium channels in the beta cell membrane.
Diclofenac is only found in individuals that have used or taken this drug. It is a non-steroidal anti-inflammatory agent (NSAID) with antipyretic and analgesic actions. It is primarily available as the sodium salt. [PubChem]The antiinflammatory effects of diclofenac are believed to be due to inhibition of both leukocyte migration and the enzyme cylooxygenase (COX-1 and COX-2), leading to the peripheral inhibition of prostaglandin synthesis. As prostaglandins sensitize pain receptors, inhibition of their synthesis is responsible for the analgesic effects of diclofenac. Antipyretic effects may be due to action on the hypothalamus, resulting in peripheral dilation, increased cutaneous blood flow, and subsequent heat dissipation.
Dihydrocapsaicin is found in pepper (C. annuum). It is a potential nutriceutical. Dihydrocapsaicin is a capsaicinoid and analog and congener of capsaicin in chili peppers (Capsicum). Like capsaicin it is an irritant. Dihydrocapsaicin accounts for about 22% of the total capsaicinoids mixture and has about the same pungency as capsaicin. Pure dihydrocapsaicin is a lipophilic colorless odorless crystalline to waxy compound. It is soluble in dimethyl sulfoxide and 100 % ethanol.
A meperidine congener used as an antidiarrheal, usually in combination with atropine. At high doses, it acts like morphine. Its unesterified metabolite difenoxin has similar properties and is used similarly. It has little or no analgesic activity. This medication is classified as a Schedule V under the Controlled Substances Act by the Food and Drug Administration (FDA) and the DEA in the United States when used in preparations. When diphenoxylate is used alone, it is classified as a Schedule II.
A carbamate derivative used as an alcohol deterrent. It is a relatively nontoxic substance when administered alone, but markedly alters the intermediary metabolism of alcohol. When alcohol is ingested after administration of disulfiram, blood acetaldehyde concentrations are increased, followed by flushing, systemic vasodilation, respiratory difficulties, nausea, hypotension, and other symptoms (acetaldehyde syndrome). It acts by inhibiting aldehyde dehydrogenase. [PubChem]
Dimethyl sulfoxide (DMSO) is a key dipolar aprotic solvent. It is less toxic than other members of this class: dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, HMPA. Dimethyl sulfoxide is the chemical compound (CH3)2SO. This colorless liquid is an important "dipolar aprotic solvent." It is readily miscible in a wide range of organic solvents as well as water. It has a distinctive property of penetrating the skin very readily, allowing the handler to taste it. Some describe it as an "oyster-like" taste, others claim it tastes like garlic. DMSO is also employed as a rinsing agent in the electronics industry and, in its deuterated form (DMSO-d6), is a useful solvent in NMR due to its ability to dissolve a wide range of chemical compounds and its minimal interference with the sample signals. In cryobiology DMSO has been used as a cryoprotectant and is still an important constituent of cryoprotectant vitrification mixtures used to preserve organs, tissues, and cell suspensions. It is particularly important in the freezing and long-term storage of embryonic stem cells and hematopoietic stem cell, which are often frozen in a mixture of 10% DMSO and 90% fetal calf serum. As part of an autologous bone marrow transplant the DMSO is re-infused along with the patient's own hematopoietic stem cell. Dimethyl sulfoxide is a by-product of wood pulping. One of the leading suppliers of DMSO is the Gaylord company in the USA. DMSO is frequently used as solvent in a number of chemical reactions. In particular it is an excellent reaction solvent for SN2 alkylations: it is possible to alkylate indoles with very high yields using potassium hydroxide as the base and a similar reaction also occurs with phenols. DMSO can be reacted with methyl iodide to form a sulfoxonium ion which can be reacted with sodium hydride to form a sulfur ylide. The methyl groups of DMSO are somewhat acidic in character (pKa=35) due to the stabilization of the resultant anions by the sulfoxide group.
Dofetilide is a class III antiarrhythmic agent that is approved by the Food and Drug Administration (FDA) for the maintenance of sinus rhythm in individuals prone to the formation of atrial fibrillation and flutter, and for the chemical cardioversion to sinus rhythm from atrial fibrillation and flutter. [Wikipedia]
Doxapram is only found in individuals that have used or taken this drug. It is a central respiratory stimulant with a brief duration of action. (From Martindale, The Extra Pharmocopoeia, 30th ed, p1225)Doxapram produces respiratory stimulation mediated through the peripheral carotid chemoreceptors. It is thought to stimulate the carotid body by inhibiting certain potassium channels.
Doxorubicin is only found in individuals that have used or taken this drug. It is antineoplastic antibiotic obtained from Streptomyces peucetius. It is a hydroxy derivative of daunorubicin. [PubChem]Doxorubicin has antimitotic and cytotoxic activity through a number of proposed mechanisms of action: Doxorubicin forms complexes with DNA by intercalation between base pairs, and it inhibits topoisomerase II activity by stabilizing the DNA-topoisomerase II complex, preventing the religation portion of the ligation-religation reaction that topoisomerase II catalyzes.
Doxylamine is a sedating antihistamine that can be used by itself as a short-term sleep aid, in combination with other drugs as a night-time cold and allergy relief. It is a member of the ethanolamine class of antihistamines and has anti-allergy power superior to almost every other antihistamine on the market, with the exception of diphenhydramine (Benadryl). It is also the most effective over-the-counter sedative available in North America, and more sedating than some prescription hypnotics. In a study, it was found that doxylamine succinate is possibly more effective than the barbiturate, phenobarbital for use as a sedative. For this reason, doxylamine has sometimes been used off label in a manner similar to diphenhydramine for the reduction of anxiety symptoms; Doxylamine succinate is used by itself as a short-term sleep aid, in combination with other drugs as a night-time cold and allergy relief drug, and a preparation is prescribed in combination with Vitamin B6 (pyridoxine) to prevent morning sickness in pregnant women. In Commonwealth countries, doxylamine is available prepared with paracetamol/acetaminophen and codeine under the brand name Syndol or Mersyndol, as treatment for tension headache and other types of pain, or as a general OTC sleep-aid branded as Somnil, Donormyl, DSozile and Restavit containing Doxylamine Succinate only.
A butyrophenone with general properties similar to those of haloperidol. It is used in conjunction with an opioid analgesic such as fentanyl to maintain the patient in a calm state of neuroleptanalgesia with indifference to surroundings but still able to cooperate with the surgeon. It is also used as a premedicant, as an antiemetic, and for the control of agitation in acute psychoses. (From Martindale, The Extra Pharmacopoeia, 29th ed, p593)
Duloxetine (brand names Cymbalta, Yentreve, and in parts of Europe, Xeristar or Ariclaim) is a drug which primarily targets major depressive disorder (MDD), generalized anxiety disorder (GAD), pain related to diabetic peripheral neuropathy and in some countries stress urinary incontinence (SUI). It is manufactured and marketed by Eli Lilly and Company. Duloxetine has not yet been FDA approved for stress urinary incontinence or for fibromyalgia. Duloxetine is a selective SNRI (selective serotonin-norepinephrine reuptake inhibitor). Duloxetine is a systemic drug therapy which affects the body as a whole. Known also under the code name LY248686, it is a potent dual reuptake inhibitor of serotonin (5-hydroxytryptamine, 5-HT) and norepinephrine (NE), possessing comparable affinities in binding to NE- and 5-HT transporter sites. It is a less potent inhibitor of dopamine reuptake.
Efavirenz (brand names Sustiva and Stocrin) is a non-nucleoside reverse transcriptase inhibitor (NNRTI) and is used as part of highly active antiretroviral therapy (HAART) for the treatment of a human immunodeficiency virus (HIV) type 1.
Enalaprilat belongs to the family of Peptides. These are compounds containing an amide derived from two or more amino carboxylic acid molecules (the same or different) by formation of a covalent bond from the carbonyl carbon of one to the nitrogen atom of another. Enalaprilat is the active drug form of the ACE inhibitor Enalapril.
Enrofloxacin is a veterinary antibacterial agent, used in poultry. Enrofloxacin is a fluoroquinolone antibiotic sold by the Bayer Corporation under the trade name Baytril(r). Enrofloxacin is currently FDA-approved for treatment of individual pets and domestic animals in the United States. In September 2005, the FDA withdrew approval of Baytril for use in water to treat flocks of poultry, as this practice was noted to promote the evolution of fluoroquinolone-resistant strains of the bacterium Campylobacter, a human pathogen. Fluoroquinolones such as ciprofloxacin are widely used in the treatment of human disease. Enrofloxacin is a synthetic chemotherapeutic agent from the class of the fluoroquinolone carboxylic acid derivatives. It has antibacterial activity against a broad spectrum of Gram-negative and Gram-positive bacteria. Its mechanism of action is not thoroughly understood, but it is believed to act by inhibiting bacterial DNA gyrase (a type-II topoisomerase), thereby preventing DNA supercoiling and DNA synthesis. It is a bactericidal agent. The bactericidal activity of enrofloxacin is concentration dependent, with susceptible bacteria cell death occurring within 20-30 minutes of exposure. Enrofloxacin has demonstrated a significant post-antibiotic effect for both Gram-negative and Gram-positive bacteria and is active in both stationary and growth phases of bacterial replication. http://www.fda.gov/cvm/Documents/baytrilDDL.pdf is a broken lin
Epicatechin is an antioxidant flavonoid, occurring especially in woody plants as both (+)-catechin and (-)-epicatechin (cis) forms. Catechin is a tannin peculiar to green and white tea because the black tea oxidation process reduces catechins in black tea. Catechin is a powerful, water soluble polyphenol and antioxidant that is easily oxidized. Several thousand types are available in the plant world. As many as two thousand are known to have a flavon structure and are called flavonoids. Catechin is one of them. Green tea is manufactured from fresh, unfermented tea leaves; the oxidation of catechins is minimal, and hence they are able to serve as antioxidants. Researchers believe that catechin is effective because it easily sticks to proteins, blocking bacteria from adhering to cell walls and disrupting their ability to destroy them. Viruses have hooks on their surfaces and can attach to cell walls. The catechin in green tea prevents viruses from adhering and causing harm. Catechin reacts with toxins created by harmful bacteria (many of which belong to the protein family) and harmful metals such as lead, mercury, chrome, and cadmium. From its NMR espectra, there is a doubt on 2 and 3 atoms configuration. It seems to be that they are in trans position.
(-)-Epigallocatechin is found in almond. (-)-Epigallocatechin is widespread in plants; broad beans are an especially good source; present in green and black tea. Potential nutriceutica
Epirubicin is only found in individuals that have used or taken this drug. It is an anthracycline which is the 4&#39;-epi-isomer of doxorubicin. The compound exerts its antitumor effects by interference with the synthesis and function of DNA. [PubChem]Epirubicin has antimitotic and cytotoxic activity. It inhibits nucleic acid (DNA and RNA) and protein synthesis through a number of proposed mechanisms of action: Epirubicin forms complexes with DNA by intercalation between base pairs, and it inhibits topoisomerase II activity by stabilizing the DNA-topoisomerase II complex, preventing the religation portion of the ligation-religation reaction that topoisomerase II catalyzes. It also interferes with DNA replication and transcription by inhibiting DNA helicase activity.
Ergosterol, also known as provitamin D2, belongs to the class of organic compounds known as ergosterols and derivatives. These are steroids containing ergosta-5,7,22-trien-3beta-ol or a derivative thereof, which is based on the 3beta-hydroxylated ergostane skeleton. Thus, ergosterol is considered to be a sterol lipid molecule. Ergosterol is a very hydrophobic molecule, practically insoluble (in water), and relatively neutral. Ergosterol is the biological precursor to vitamin D2. It is turned into viosterol by ultraviolet light, and is then converted into ergocalciferol, which is a form of vitamin D. Ergosterol is a component of fungal cell membranes, serving the same function that cholesterol serves in animal cells. Ergosterol is not found in mammalian cell membranes.
Ergothioneine is a naturally occurring metabolite of histidine that has antioxidant properties. -- Pubchem. Ergothioneine is a product of plant origin that accumulates in animal tissues. Ergothioneine is biosynthesized exclusively by fungi and mycobacteria and is captured by plants through their roots. As an ingredient of human food, ET is distributed very unevenly. By far, the highest levels of Ergothioneine have been found in mushrooms (0.1-1 mg/g dried material). Ergothioneine is rapidly cleared from the circulation and then avidly retained with minimal metabolism: the whole-body half-life of ingested Ergothioneine in rats is 1 month. The content of Ergothioneine varies greatly among tissues and is strongly dependent on its dietary level. In addition to erythrocytes and bone marrow, high Ergothioneine levels have also been found in seminal fluid. The precise physiological role of ET has remained elusive since its discovery in 1909. It is known that Ergothioneine is a powerful scavenger of hydroxyl radicals and an inhibitor of iron or copper ion-dependent generation of hydroxyl radicals from hydrogen peroxide (H2O2). A specific ergothioneine transporter has recently been identified (gene symbol SLC22A4 - PMID: 15795384). Ergothioneine appears to play a pivotal protective role in monocytes, because the occurrence of rheumatoid arthritis and Crohn's disease has very recently been linked to variant ergothioneine transporter genes (PMID: 15795384). SLC22A4 is highly expressed in the kidney, where it is thought to aid in active secretion of organic cations, and may facilitate the active reabsorption of ergothioneine.
Escitalopram is a furancarbonitrile that is one of the Serotonin uptake inhibitors used as an antidepressant. The drug is also effective in reducing ethanol uptake in alcoholics and is used in depressed patients who also suffer from tardive dyskinesia in preference to tricyclic antidepressants, which aggravate this condition; Escitalopram (Cipralex) is a medication developed by the Danish pharmaceutical company Lundbeck, that acts as a selective serotonin reuptake inhibitor (SSRI). It is typically used as an antidepressant to treat depression associated with mood disorders, although it also may be used in the treatment of body dysmorphic disorder and anxiety, including OCD. In the United States, the drug is marketed under the name Lexapro by Forest Laboratories, Inc; Escitalopram is a medication that acts as a selective serotonin reuptake inhibitor (SSRI). It is typically used as an antidepressant to treat depression associated with mood disorders, although it also may be used in the treatment of body dysmorphic disorder and anxiety, including OCD; Discontinuation from antidepressants, especially abruptly, has been known to cause certain withdrawal symptoms. One possible discontinuation symptom from Escitalopram is a type of spontaneous nerve pulse known as paresthesia or 'electric shock sensations', described by some patients as a feeling of small electric shocks, which may be accompanied by dizziness. These pulses may be short in duration, only milliseconds long, may affect any region of the body, and recur up to several times a minute, throughout all waking hours. They can be increased by physical activity, but are not solely linked to muscular activity. Other discontinuation symptoms include extreme sensitivity to loud sounds and bright lights, chills, hot flushes, cold sweats, reddening of the face, abdominal pain, weight gain and extreme mental fatigue.
Esmolol (trade name Brevibloc) is a cardioselective beta1 receptor blocker with rapid onset, a very short duration of action, and no significant intrinsic sympathomimetic or membrane stabilising activity at therapeutic dosages. Esmolol decreases the force and rate of heart contractions by blocking beta-adrenergic receptors of the sympathetic nervous system, which are found in the heart and other organs of the body. Esmolol prevents the action of two naturally occurring substances: epinephrine and norepinephrine.
Esomeprazole (brand names Nexium; Lucen; Esopral and Axagon in Italy) is a proton pump inhibitor which reduces gastric acid secretion through the inhibition of H+/K+-ATPase in gastric parietal cells. By inhibiting the functioning of this enzyme, the drug prevents the formation of gastric acid. Esomeprazole is used in the treatment of dyspepsia, peptic ulcer disease (PUD), gastroesophageal reflux disease (GORD/GERD), and Zollinger-Ellison syndrome. Esomeprazole is the S-enantiomer of omeprazole (marketed as Losec/Prilosec), and AstraZeneca claims improved efficacy of this single enantiomer product over the racemic mixture of omeprazole.
Ethanolamine (MEA), also known as monoethanolamine, aminoethanol or glycinol, belongs to the class of organic compounds known as 1,2-aminoalcohols (or simply aminoalcohols). These are organic compounds containing an alkyl chain with an amine group bound to the C1 atom and an alcohol group bound to the C2 atom. Ethanolamine is a colorless, viscous liquid with an odor reminiscent of ammonia. In pharmaceutical formulations, ethanolamine is used primarily for buffering or preparation of emulsions. Ethanolamine can also be used as pH regulator in cosmetics. Biologically, ethanolamine is an initial precursor for the biosynthesis of two primary phospholipid classes, phosphatidylcholine (PC) and phosphatidylethanolamine (PE). In this regard, ethanolamine is the second-most-abundant head group for phospholipids. Ethanolamine serves as a precursor for a variety of N-acylethanolamines (NAEs). These are molecules that modulate several animal and plant physiological processes such as seed germination, plant‚Äìpathogen interactions, chloroplast development and flowering (PMID: 30190434). Ethanolamine, when combined with arachidonic acid (C20H32O2; 20:4, œâ-6), can also form the endocannabinoid anandamide. Ethanolamine can be converted to phosphoethanolamine via the enzyme known as ethanolamine kinase. the two substrates of this enzyme are ATP and ethanolamine, whereas its two products are ADP and O-phosphoethanolamine. In most plants ethanolamine is biosynthesized by decarboxylation of serine via a pyridoxal 5'-phosphate-dependent l-serine decarboxylase (SDC). Ethanolamine exists in all living species, ranging from bacteria to plants to humans. Ethanolamine has been detected, but not quantified in, several different foods, such as narrowleaf cattails, mung beans, blackcurrants, white cabbages, and bilberries.
Ethyl butyrate, also known as ethyl butanoate, or butyric ether, is an ester with the chemical formula CH3CH2CH2COOCH2CH3, with one oxygen having a double bond. It is soluble in propylene glycol, paraffin oil and kerosene. Ethyl butyrate is present in many fruits e.g. apple, apricot, banana, plum, tangerine etc. Ethyl butyrate is a flavouring ingredient and it can be synthesized by reacting ethanol and butyric acid. This is a condensation reaction, meaning water is produced in the reaction as a byproduct.
Ethinyl estradiol. A semisynthetic alkylated estradiol with a 17-alpha-ethinyl substitution. It has high estrogenic potency when administered orally, and is often used as the estrogenic component in oral contraceptives. -- Pubchem; estradiol (17-beta estradiol) (also oestradiol) is a sex hormone. Labelled the "female" hormone but also present in males it represents the major estrogen in humans. Critical for sexual functioning, estradiol also supports bone growth. -- Wikipedia; One of the fascinating twists to mammalian sexual differentiation is that estradiol is one of the two active metabolites of testosterone in males (the other being dihydrotestosterone). estradiol cannot be transferred readily from the circulation into the brain. Since fetuses of both sexes are exposed to similarly high levels of maternal estradiol, it can play little role in prenatal sexual differentiation. However, testosterone enters the central nervous system more freely and significant amounts are aromatized to estradiol within the brain of most male mammals, including humans. There is now much evidence that the programming of adult male sexual behavior in "lower mammals," (such as mounting rather than lordosis behavior), is largely dependent on estradiol produced in the central nervous system during prenatal life and early infancy from testosterone. We do not yet know whether this process plays a minimal or significant part in human sexual behaviors. -- Wikipedia; A synthetic form of estradiol, called ethinyl estradiol is a major component of hormonal contraceptive devices. Combined oral contraceptives contain ethinyl estradiol and a progestin, which both contribute to the inhibition of GnRH, LH, and FSH. The inhibition of these hormones accounts for the ability of combined oral contraceptives or birth control pills to prevent ovulation and thus prevent pregnancy. Other types of hormonal birth control contain only progestins and no ethinyl estradiol. -- Wikipedia.
Etomidate is only found in individuals that have used or taken this drug. It is an midazole derivative anesthetic and hypnotic with little effect on blood gases, ventilation, or the cardiovascular system. It has been proposed as an induction anesthetic. [PubChem]Etomidate binds at a distinct binding site associated with a Cl<sup>-</sup> ionopore at the GABA<sub>A</sub> receptor, increasing the duration of time for which the Cl<sup>-</sup> ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged.
Etoposide, also known as vepesid or VP-16, belongs to the class of organic compounds known as podophyllotoxins. These are tetralin lignans in which the benzene moiety of the tetralin skeleton is fused to a 1,3-dioxolane and the cyclohexane is fused to a butyrolactone (pyrrolidin-2-one). Etoposide is a drug. Within humans, etoposide participates in a number of enzymatic reactions. In particular, etoposide can be converted into etoposide ortho-quinone; which is mediated by the enzymes prostaglandin g/h synthase 1 and prostaglandin g/h synthase 2. In addition, etoposide and uridine diphosphate glucuronic acid can be converted into etoposide glucuronide and uridine 5'-diphosphate; which is mediated by the enzyme UDP-glucuronosyltransferase 1-1. In humans, etoposide is involved in etoposide metabolism pathway. Etoposide is formally rated as a carcinogen (by IARC 1) and is also a potentially toxic compound. Etoposide is used as a form of chemotherapy for cancers such as Kaposi's sarcoma, Ewing's sarcoma, lung cancer, testicular cancer, lymphoma, nonlymphocytic leukemia, and glioblastoma multiforme. It is given intravenously (IV) or orally in capsule or tablet form. It is believed to work by damaging DNA. Etoposide was approved for medical use in the United States in 1983. They can include low blood cell counts, vomiting, loss of appetite, diarrhea, hair loss, and fever.
Exemestane is an oral steroidal aromatase inhibitor used in the adjuvant treatment of hormonally-responsive (also called hormone-receptor-positive, estrogen-responsive) breast cancer in postmenopausal women. It acts as a false substrate for the aromatase enzyme, and is processed to an intermediate that binds irreversibly to the active site of the enzyme causing its inactivation.
Ezetimibe is an anti-hyperlipidemic medication which is used to lower cholesterol levels. Specifically, it appears to bind to a critical mediator of cholesterol absorption, the Niemann-Pick C1-Like 1 (NPC1L1) protein on the gastrointestinal tract epithelial cells as well as in hepatocytes.
Flavin adenine dinucleotide (FAD) is a redox-active coenzyme associated with various proteins, which is involved with several enzymatic reactions in metabolism. FAD, also known as adeflavin or flamitajin b, belongs to the class of organic compounds known as flavin nucleotides. These are nucleotides containing a flavin moiety. Flavin is a compound that contains the tricyclic isoalloxazine ring system, which bears 2 oxo groups at the 2- and 4-positions. FAD is a drug which is used to treat eye diseases caused by vitamin b2 deficiency, such as keratitis and blepharitis. FAD exists in all living species, ranging from bacteria to humans. In humans, FAD is involved in the metabolic disorder called the medium chain acyl-coa dehydrogenase deficiency (mcad) pathway. Outside of the human body, FAD has been detected, but not quantified in several different foods, such as other bread, passion fruits, asparagus, kelps, and green bell peppers. It is a flavoprotein in which the substituent at position 10 of the flavin nucleus is a 5'-adenosyldiphosphoribityl group.
Famciclovir is a guanine analogue antiviral drug used for the treatment of various herpes virus infections, most commonly for herpes zoster (shingles). It is a prodrug form of penciclovir with improved oral bioavailability. Famciclovir is marketed under the trade name Famvir (Novartis).
Famotidine is a histamine H2-receptor antagonist that inhibits stomach acid production, and is commonly used in the treatment of peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD/GORD). It is commonly marketed by Merck under the trade names Pepcidine and Pepcid.
Felbamate is an anticonvulsant drug used in the treatment of epilepsy. It is used to treat partial seizures (with and without generalization) in adults and partial and generalized seizures associated with Lennox-Gastaut syndrome in children. It has a weak inhibitory effect on GABA receptor binding sites.
Fenoldopam is only found in individuals that have used or taken this drug. It is a dopamine D1 receptor agonist that is used as an antihypertensive agent. It lowers blood pressure through arteriolar vasodilation. [PubChem]Fenoldopam is a rapid-acting vasodilator. It is an agonist for D<sub>1</sub>-like dopamine receptors and binds with moderate affinity to &alpha;<sub>2</sub>-adrenoceptors. It has no significant affinity for D<sub>2</sub>-like receptors, &alpha;<sub>1</sub> and &beta;-adrenoceptors, 5<sub>HT1</sub> and 5<sub>HT2</sub> receptors, or muscarinic receptors. Fenoldopam is a racemic mixture with the R-isomer responsible for the biological activity. The R-isomer has approximately 250-fold higher affinity for D<sub>1</sub>-like receptors than does the S-isomer. In non-clinical studies, fenoldopam had no agonist effect on presynaptic D<sub>2</sub>-like dopamine receptors, or &alpha; or &beta; -adrenoceptors, nor did it affect angiotensin-converting enzyme activity. Fenoldopam may increase norepinephrine plasma concentration.
trans-Ferulic acid is a highly abundant phenolic phytochemical which is present in plant cell walls. Ferulic acid is a phenolic acid that can be absorbed by the small intestine and excreted through the urine. It is one of the most abundant phenolic acids in plants, varying from 5 g/kg in wheat bran to 9 g/kg in sugar-beet pulp and 50 g/kg in corn kernel. It occurs primarily in seeds and leaves both in its free form (albeit rarely) and covalently linked to lignin and other biopolymers. It is usually found as ester cross-links with polysaccharides in the cell wall, such as arabinoxylans in grasses, pectin in spinach and sugar beet, and xyloglucans in bamboo. It also can cross-link with proteins. Due to its phenolic nucleus and an extended side chain conjugation (carbohydrates and proteins), it readily forms a resonance-stabilized phenoxy radical which accounts for its potent antioxidant potential. Food supplementation with curcumin and ferulic acid is considered a nutritional approach to reducing oxidative damage and amyloid pathology in Alzheimer disease (PMID:17127365, 1398220, 15453708, 9878519). Ferulic acid can be found in Pseudomonas and Saccharomyces (PMID:8395165).
Flumazenil is only found in individuals that have used or taken this drug.Flumazenil, an imidazobenzodiazepine derivative, antagonizes the actions of benzodiazepines on the central nervous system. Flumazenil competitively inhibits the activity at the benzodiazepine recognition site on the GABA/benzodiazepine receptor complex, thereby reversing the effects of benzodiazepine on the central nervous system. Flumazenil is a weak partial agonist in some animal models of activity, but has little or no agonist activity in man.
A benzodiazepine with pharmacologic actions similar to those of diazepam that can cause anterograde amnesia. Some reports indicate that it is used as a date rape drug and suggest that it may precipitate violent behavior. The United States Government has banned the importation of this drug. [PubChem]
Fluphenazine is only found in individuals that have used or taken this drug. It is a phenothiazine used in the treatment of psychoses. Its properties and uses are generally similar to those of chlorpromazine. [PubChem]Fluphenazine blocks postsynaptic mesolimbic dopaminergic D1 and D2 receptors in the brain; depresses the release of hypothalamic and hypophyseal hormones and is believed to depress the reticular activating system thus affecting basal metabolism, body temperature, wakefulness, vasomotor tone, and emesis.
Flurazepam is only found in individuals that have used or taken this drug. It is a benzodiazepine derivative used mainly as a hypnotic. [PubChem]Flurazepam binds to an allosteric site on GABA-A receptors. Binding potentiates the action of GABA on GABA-A receptors by opening the chloride channel within the receptor, causing chloride influx and hyperpolarization.
Formononetin are abundant in vegetables. It is a phyto-oestrogen that is a polyphenolic non-steroidal plant compound with oestrogen-like biological activity (PMID: 16108819). It can be the source of considerable estrogenic activity (http://www.herbalchem.net/Intermediate.htm).
Formoterol is a long-acting (12 hours) beta2-agonist used in the management of asthma and/or chronic obstructive pulmonary disease (COPD). Inhaled formoterol works like other beta2-agonists, causing bronchodilatation through relaxation of the smooth muscle in the airway so as to treat the exacerbation of asthma.
A benzazepine derived from norbelladine. It is found in galanthus and other amaryllidaceae. Galantamine is a cholinesterase inhibitor that has been used to reverse the muscular effects of gallamine triethiodide and tubocurarine, and has been studied as a treatment for Alzheimer's disease and other central nervous system disorders. [PubChem]
gamma-Glutamylleucine is a dipeptide composed of gamma-glutamate and leucine, and is a proteolytic breakdown product of larger proteins. It belongs to the family of N-acyl-alpha amino acids and derivatives. These are compounds containing an alpha amino acid which bears an acyl group at its terminal nitrogen atom. gamma-Glutamylleucine is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis. gamma-Glutamylleucine is a biomarker for the consumption of whey protein. It is found in urine (PMID: 3782411).
gamma-Glutamylmethionine is a dipeptide composed of gamma-glutamate and methionine, and is a proteolytic breakdown product of larger proteins. It belongs to the family of N-acyl-alpha amino acids and derivatives. These are compounds containing an alpha amino acid which bears an acyl group at its terminal nitrogen atom. gamma-Glutamylmethionine is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis. gamma-Glutamylmethionine is found in onion-family vegetables. It is isolated from the seeds of onion (Allium cepa), kidney bean (Phaseolus vulgaris), mung bean (Vigna radiata), garlic (Allium sativum), and black gram (Vigna mungo).
gamma-Glutamyltyrosine is a dipeptide composed of gamma-glutamate and tyrosine, and is a proteolytic breakdown product of larger proteins. It belongs to the family of N-acyl-alpha amino acids and derivatives. These are compounds containing an alpha amino acid which bears an acyl group at its terminal nitrogen atom. gamma-Glutamyltyrosine is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis.
Gentisic acid, also known as gentisate or 2,5-dioxybenzoate, belongs to the class of organic compounds known as hydroxybenzoic acid derivatives. Hydroxybenzoic acid derivatives are compounds containing a hydroxybenzoic acid (or a derivative), which is a benzene ring bearing a carboxyl and a hydroxyl groups. Gentisic acid is also classified as a dihydroxybenzoic acid.  It is a derivative of benzoic acid and a minor (1%) product of the metabolic break down of aspirin, which is excreted by the kidneys. Gentisic acid is found in essentially all organisms ranging from bacteria to fungi to plants to animals. Gentisic acid has been associated with a number of useful effects on human health and exhibits anti-inflammatory, antigenotoxic, hepatoprotective, neuroprotective, antimicrobial, and especially antioxidant activities (PMID: 31825145). It is widely distributed in plants as a secondary plant product such as Gentiana spp., Citrus spp., Vitis vinifera, Pterocarpus santalinus, Helianthus tuberosus, Hibiscus rosa-sinensis, Olea europaea, and Sesamum indicum and in fruits such as avocados, batoko plum, kiwi fruits, apple, bitter melon, black berries, pears, and some mushrooms (PMID: 31825145). Gentisic acid is found in higher concentrations in a number of foods such as tarragons, common thymes, and common sages and in a lower concentration in grape wines, rosemaries, and sweet marjorams. Gentisic acid has also been shown to act as a pathogen-inducible signal for the activation of plant defenses in tomato plants and cucumbers (PMID: 16321412; https://doi.org/10.1094/MPMI.1999.12.3.227).
Glimepiride is only found in individuals that have used or taken this drug. It is the first III generation sulphonyl urea it is a very potent sulphonyl urea with long duration of action.The mechanism of action of glimepiride in lowering blood glucose appears to be dependent on stimulating the release of insulin from functioning pancreatic beta cells, and increasing sensitivity of peripheral tissues to insulin. Glimepiride likely binds to ATP-sensitive potassium channel receptors on the pancreatic cell surface, reducing potassium conductance and causing depolarization of the membrane. Membrane depolarization stimulates calcium ion influx through voltage-sensitive calcium channels. This increase in intracellular calcium ion concentration induces the secretion of insulin.
Glucoraphanin belongs to the class of organic compounds known as alkylglucosinolates. These are organic compounds containing a glucosinolate moiety that carries an alkyl chain. Outside of the human body, glucoraphanin has been detected, but not quantified in, several different foods, such as radish, common cabbages, Brassicas, Chinese cabbages, and cabbages. This could make glucoraphanin a potential biomarker for the consumption of these foods.
Oxidized glutathione, also known as glutathione disulfide or GSSG, belongs to the class of organic compounds known as peptides. Peptides are compounds containing an amide derived from two or more amino carboxylic acid molecules (the same or different) by the formation of a covalent bond from the carbonyl carbon of one to the nitrogen atom of another. In humans, oxidized glutathione is involved in the metabolic disorder called leukotriene C4 synthesis deficiency pathway. Outside of the human body, oxidized glutathione has been detected, but not quantified in several different foods, such as leeks, star anises, mamey sapotes, climbing beans, and common persimmons. Oxidized glutathione is a glutathione dimer formed by a disulfide bond between the cysteine sulfhydryl side chains during the course of being oxidized. Glutathione participates in leukotriene synthesis and is a cofactor for the enzyme glutathione peroxidase. It is also important as a hydrophilic molecule that is added to lipophilic toxins and waste in the liver during biotransformation before they can become part of the bile. Glutathione is also needed for the detoxification of methylglyoxal, a toxin produced as a by-product of metabolism. This detoxification reaction is carried out by the glyoxalase system. Glyoxalase I (EC 4.4.1.5) catalyzes the conversion of methylglyoxal and reduced glutathione into S-D-lactoyl-glutathione. Glyoxalase II (EC 3.1.2.6) catalyzes the hydrolysis of S-D-lactoyl-glutathione into glutathione and D-lactate.
Glycyl-Isoleucine is a dipeptide composed of glycine and isoleucine. It is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis. This dipeptide has not yet been identified in human tissues or biofluids and so it is classified as an 'Expected' metabolite.
Glycylleucine is a dipeptide composed of glycine and leucine. It is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis. It appears to be a common substrate for glycyl-leucine dipeptidase.
Glycitein is a soy isoflavone. It is a minor component in most soy products. It's role of reducing low-density lipoprotein cholesterol is not clear. Glycitein is metabolized by human gut microorganisms and may follow metabolic pathways similar to other soy isoflavones (PMID: 12011578; 16248547). Glycitein is a biomarker for the consumption of soy beans and other soy products.
Goserelin is a synthetic hormone. In men, it stops the production of the hormone testosterone, which may stimulate the growth of cancer cells. In women, goserelin decreases the production of the hormone estradiol (which may stimulate the growth of cancer cells) to levels similar to a postmenopausal state. When the medication is stopped, hormone levels return to normal.
Guanidoacetic acid (GAA), also known as guanidinoacetate or glycocyamine, belongs to the class of organic compounds known as alpha amino acids and derivatives. These are amino acids in which the amino group is attached to the carbon atom immediately adjacent to the carboxylate group (alpha carbon), or a derivative thereof. Guanidinoacetic acid was first prepared in 1861 by Adolph Strecker by reaction of cyanamide with glycine in aqueous solution. Manufactured guanidinoacetic acid is primarily used a feed additive approved by EFSA in poultry farming (for fattening), and pigs for fattening. Guanidoacetic acid exists naturally in all vertebrates. It is formed primarily in the kidneys by transferring the guanidine group of L-arginine to the amino acid glycine via the enzyme known as L-Arg:Gly-amidinotransferase (AGAT). In a further step, guanidinoacetate is methylated to generate creatine using S-adenosyl methionine (as the methyl donor) via the enzyme known as guanidinoacetate N-methyltransferase (GAMT). The resulting creatine is released into the bloodstream. Elevated levels of guanidoacetic acid are a characteristic of an inborn metabolic disorder known as Guanidinoacetate Methyltransferase (GAMT) Deficiency. GAMT converts guanidinoacetate to creatine and deficiency of this enzyme results in creatine depletion and accumulation of guanidinoacetate The disorder is transmitted in an autosomal recessive fashion and is localized to mutations on chromosome 19p13.3. GAMT deficiency is characterized by developmental arrest, medication-resistant epilepsy (myoclonic, generalized tonic-clonic, partial complex, atonic), severe speech impairment, progressive dystonia, dyskinesias, hypotonia, ataxia, and autistic-like behavior.
N2-gamma-Glutamylglutamine, also known as gamma-L-Glu-L-Gln or L-gamma-glutamyl-L-glutamine, belongs to the class of organic compounds known as dipeptides. These are organic compounds containing a sequence of exactly two alpha-amino acids joined by a peptide bond. N2-gamma-Glutamylglutamine is a very strong basic compound (based on its pKa). N2-gamma-Glutamylglutamine is a dipeptide obtained from the condensation of the gamma-carboxy group of glutamic acid with the alpha-amino group of glutamine. Some dipeptides are known to have physiological or cell-signalling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis.
Prolylhydroxyproline is a dipeptide. Prolylhydroxyproline is a marker of bone collagen degradation, showing high sensitivity for the diagnosis of osteoporosis. Prolylhydroxyproline has been suggested as a possible alternative to hydroxyproline determination in bone resorption studies. Prolylhydroxyproline is one of the iminodipeptides present in the urine of patients with prolidase deficiency. Prolidase (X-Pro dipeptidase EC 3.4.13.9) splits iminodipeptides containing C-terminal proline or hydroxyproline (X-Pro or X-Hyp) to X+Pro or X+Hyp. Prolidase deficiency is a rare autosomal recessive disease characterized by chronic ulcerative dermatitis and mental retardation. These patients excrete large amounts of iminodipeptides containing C-terminal proline in the urine due to hereditary prolidase deficiency (PMID: 12636053, 11863289, 2387877, 1874885, 9586797).
A phenyl-piperidinyl-butyrophenone that is used primarily to treat schizophrenia and other psychoses. It is also used in schizoaffective disorder, delusional disorders, ballism, and tourette syndrome (a drug of choice) and occasionally as adjunctive therapy in mental retardation and the chorea of huntington disease. It is a potent antiemetic and is used in the treatment of intractable hiccups. (From AMA Drug Evaluations Annual, 1994, p279)
Heptadecanoic acid is a fatty acid of exogenous (primarily ruminant) origin. Many "odd" length long chain amino acids are derived from the consumption of dairy fats (milk and meat). Heptadecanoic acid constitutes 0.61% of milk fat and 0.83% of ruminant meat fat. The content of heptadecanoic acid in the subcutaneous adipose tissue of humans appears to be a good biological marker of long-term milk fat intake in free-living individuals in populations with high consumption of dairy products. (PMID 9701185).
Caproic acid, also known as hexanoic acid or C6:0, is a medium-chain fatty acid. Medium-chain fatty acids (MCFA) are fatty acids with aliphatic tails of 6 to 12 carbons, which can form medium-chain triglycerides. Caproic acid is a colourless oily liquid that smells like cheese with an overlying waxy or barnyard odor like that of goats or other barnyard animals. Its name comes from the Latin word capra, meaning "goat". Two other fatty acids are named after goats: caprylic acid (C8) and capric acid (C10). Along with caproic acid, they account for 15% of the fat in goat's milk. Caproic acid is a fatty acid found naturally in various animal fats and oils. While generally more abundant in animals, caproic acid is found in all organisms ranging from bacteria to plants to animals. Caproic acid is one of the chemicals that gives the decomposing fleshy seed coat of the ginkgo fruit its characteristic unpleasant odor. It is also one of the components of vanilla and cheese. Industrially, the primary use of caproic acid is in the manufacture of its esters for use as artificial flavors and in the manufacture of hexyl derivatives, such as hexylphenols. Caproic acid has been associated with medium chain acyl-CoA dehydrogenase deficiency, which is an inborn error of metabolism. As a relatively volatile organic compound, caproic acid has been identified as a fecal biomarker of Clostridium difficile infection (PMID: 30986230).
Hexamethylene bisacetamide belongs to the family of Imines. These are compounds containing an imine functional group, with the general structure RN=CR2 (R = H, hydrocarbyl).
L-homoarginine, also known as N6-(aminoiminomethyl)-L-lysine or N6-amidino-L-lysine, is a member of the class of compounds known as L-alpha-amino acids. L-alpha-amino acids are alpha amino acids which have the L-configuration of the alpha-carbon atom. More specifically, L-homoarginine is a naturally occurring, non-proteinogenic, cationic amino acid. It is formed in the liver in a reaction catalyzed by L-arginine:glycine amidinotransferase (AGAT) when transferring the amidino group from arginine to lysine. It is an alternative substrate for nitric oxide (NO) synthase. L-homoarginine increases the availability of NO and thereby affects endothelial function. High homoarginine levels may exert positive actions that are relevant to cardiovascular health, including enhanced endothelial function, inhibition of platelet aggregation and stimulation of insulin secretion (PMID: 30866658). Recent studies have demonstrated that low serum homoarginine levels are a strong predictor of cardiovascular mortality (PMID: 24583919). L-homoarginine is a substrate of the human cationic amino acid CAT1 [solute carrier family 7 (SLC7A1)], CAT2A (SLC7A2A) or CAT2B (SLC7A2B) (PMID: 28684763). According to published human metabolomic data, L-homoarginine can be found primarily in blood, cerebrospinal fluid (CSF), and urine, as well as in human intestinal and testes tissues. Moreover, L-homoarginine has been found to be associated with liver cirrhosis and the genetic disorder, hyperargininemia. Homoarginine is an organ-specific uncompetitive inhibitor of human liver and bone alkaline phosphohydrolase (PMID: 5063678).
Homoserine is a more reactive variant of the amino acid serine. In this variant, the hydroxyl side chain contains an additional CH2 group which brings the hydroxyl group closer to its own carboxyl group, allowing it to chemically react to form a five-membered ring. This occurs at the point that amino acids normally join to their neighbours in a peptide bond. Homoserine is therefore unsuitable for forming proteins and has been eliminated from the repertoire of amino acids used by living things. Homoserine is the final product on the C-terminal end of the N-terminal fragment following a cyanogen bromide cleavage. (wikipedia). Homoserine is also a microbial metabolite.
3,4-Dimethoxyphenylethylamine, also known as 3,4-DMPEA or DMPEA is an endogenous metabolite found in urine that belongs to both the phenethylamine and catecholamine families. DMPEA is an analogue of dopamine (3,4-dihydroxyphenethylamine), with a substitution of the hydroxy groups with methoxy groups. DMPEA is also structurally similar to mescaline (3,4,5-trimethoxyphenylethylamine) and occurs naturally alongside it in various species of cacti such as the San Pedro and Peruvian Torch (PMID: 5511715, 925910, 600028). DMPEA received wide attention after it was proposed as a biomarker in schizophrenic patients urine, however later studies revealed that DMPEA is also excreted by non-schizophrenics (PMID: 709888). DMPEA has little known bioactivity, but it has some action as a monoamine oxidase inhibitor (PMID: 886445). DMPEA has also been shown to have neurotoxic effects, especially in the nigrostriatal system and among dopaminergic neurons (PMID: 9409711, 9134983). DMPEA appears to be an inhibitor of mitochondrial complex I (PMID: 9409711).
Hydrocodone is only found in individuals that have used or taken this drug. It is a narcotic analgesic related to codeine, but more potent and more addicting by weight. It is used also as cough suppressant. [PubChem]Hydrocodone acts as a weak agonist at OP1, OP2, and OP3 opiate receptors within the central nervous system (CNS). Hydrocodone primarily affects OP3 receptors, which are coupled with G-protein receptors and function as modulators, both positive and negative, of synaptic transmission via G-proteins that activate effector proteins. Binding of the opiate stimulates the exchange of GTP for GDP on the G-protein complex. As the effector system is adenylate cyclase and cAMP located at the inner surface of the plasma membrane, opioids decrease intracellular cAMP by inhibiting adenylate cyclase. Subsequently, the release of nociceptive neurotransmitters such as substance P, GABA, dopamine, acetylcholine, and noradrenaline is inhibited. Opioids such as hydrocodone also inhibit the release of vasopressin, somatostatin, insulin, and glucagon. Opioids close N-type voltage-operated calcium channels (OP2-receptor agonist) and open calcium-dependent inwardly rectifying potassium channels (OP3 and OP1 receptor agonist). This results in hyperpolarization and reduced neuronal excitability.
Hydromorphone is only found in individuals that have used or taken this drug. It is an opioid analgesic derived from morphine and used mainly as an analgesic. It has a shorter duration of action and is more potent than morphine. [PubChem]Hydromorphone is a narcotic analgesic; its principal therapeutic effect is relief of pain. Hydromorphone interacts predominantly with the opioid mu-receptors. These mu-binding sites are discretely distributed in the human brain, with high densities in the posterior amygdala, hypothalamus, thalamus, nucleus caudatus, putamen, and certain cortical areas. They are also found on the terminal axons of primary afferents within laminae I and II (substantia gelatinosa) of the spinal cord and in the spinal nucleus of the trigeminal nerve. In clinical settings, Hydromorphone exerts its principal pharmacological effect on the central nervous system and gastrointestinal tract. Hydromorphone also binds with kappa-receptors which are thought to mediate spinal analgesia, miosis and sedation.
4-Hydroxyproline (hydroxyproline or Hyp) is a major component of the protein collagen. Hydroxyproline is produced by hydroxylation of the amino acid proline and is, therefore, a post-translationally modified, non-essential amino acid. Hydroxyproline and proline play key roles in collagen stability. In particular, they permit the sharp twisting of the collagen helix. Hydroxyproline is found in few proteins other than collagen. The only other mammalian protein which includes hydroxyproline is elastin. For this reason, hydroxyproline content has been used as an indicator to determine collagen and/or gelatin amount in tissue or biological samples. Increased serum and urine levels of hydroxyproline have been found in Paget's disease (PMID: 436278). Hydroxyproline (Hyp) content in biological fluids is used as a parameter of collagen catabolism, especially bone resorption or tissue degradation. Bedridden and elderly individuals show significantly elevated serum levels of hydroxyproline in comparison to normal, active individuals (PMID: 10706420). Elevated levels of urinary hydroxyproline are also indicative of muscle damage (PMID: 21988268). Increased reactive oxygen species (ROS) are also known to accelerate collagen degradation. Hydroxyproline levels increase in cases of depression and stress (PMID: 21483218). 4-Hydroxyproline is found to be associated with Alzheimer's disease, and also hydroxyprolinemia and iminoglycinuria which are both inborn errors of metabolism. 4-Hydroxyproline is also involved in metabolic disorders such as hyperprolinemia type I, hyperornithinemia with gyrate atrophy (HOGA), L-arginine:glycine amidinotransferase deficiency, creatine deficiency, and guanidinoacetate methyltransferase deficiency. A deficiency in ascorbic acid can result in impaired hydroxyproline formation (PubChem). trans-4-Hydroxy-L-proline is a biomarker for the consumption of processed meat.
Hyoscyamine is a chemical compound, a tropane alkaloid it is the levo-isomer to atropine. It is a secondary metabolite of some plants, particularly henbane (Hyoscamus niger.). Hyoscyamine is used to provide symptomatic relief to various gastrointestinal disorders including spasms, peptic ulcers, irritable bowel syndrome, pancreatitis, colic and cystitis. It has also been used to relieve some heart problems, control some of the symptoms of Parkinson's disease, as well as for control of respiratory secretions in end of life care.
Idarubicin is only found in individuals that have used or taken this drug. It is an orally administered anthracycline antineoplastic. The compound has shown activity against breast cancer, lymphomas and leukemias, together with the potential for reduced cardiac toxicity. [PubChem]Idarubicin has antimitotic and cytotoxic activity through a number of proposed mechanisms of action: Idarubicin forms complexes with DNA by intercalation between base pairs, and it inhibits topoisomerase II activity by stabilizing the DNA-topoisomerase II complex, preventing the religation portion of the ligation-religation reaction that topoisomerase II catalyzes.
Imatinib is a drug used to treat certain types of cancer. It is currently marketed by Novartis as Gleevec (USA) or Glivec (Europe/Australia) as its mesylate salt, imatinib mesilate (INN). It is occasionally referred to as CGP57148B or STI571 (especially in older publications). It is used in treating chronic myelogenous leukemia (CML), gastrointestinal stromal tumors (GISTs) and a number of other malignancies. It is the first member of a new class of agents that act by inhibiting particular tyrosine kinase enzymes, instead of non-specifically inhibiting rapidly dividing cells.
Imidazole is an organic compound with the formula C3N2H4. It is a white or colourless solid that is soluble in water, producing a mildly alkaline solution. In chemistry, it is an aromatic heterocycle, classified as a diazole, and has non-adjacent nitrogen atoms. Imidazole is a heterocyclic aromatic organic compound. It is classified as an alkaloid. The ring system of the molecule is present in important biological building blocks such as histidine and histamine. Imidazole can act as a base and as a weak acid. Imidazole exists in two tautomeric forms with the hydrogen atom moving between the two nitrogens. Many drugs contain an imidazole ring, such as antifungal drugs and nitroimidazole. Imidazole is a 5 membered planar ring which is soluble in water and polar solvents. Imidazole is a base and an excellent nucleophile. It reacts at the NH nitrogen, attacking alkylating and acylating compounds. It is not particularly susceptible to electrophilic attacks at the carbon atoms, and most of these reactions are substitutions that keep the aromaticity intact. One can see from the resonance structure that the carbon-2 is the carbon most likely to have a nucleophile attack it, but in general nucleophilic substitutions are difficult with imidazole. Imidazole is incorporated into many important biological molecules. The most obvious is the amino acid histidine, which has an imidazole side chain. histidine is present in many proteins and enzymes and plays a vital part in the structure and binding functions of hemoglobin.
Indirubin or indigo red is an organic compound with a distinctive deep red/orange color. It is an oxindole dimer consisting of two fused oxindole rings. Indoles are compounds which consist of a pyrrole ring fused to benzene to form 2,3-benzopyrrole. Indirubin is found in both plants and animals and has been detected in human urine and human tissues (PMID: 11076521; PMID: 8667928). The precursor to indirubin is indican, a colorless, water-soluble derivative of the amino acid tryptophan which is converted to indole via microbial metabolism. Indican readily hydrolyzes to release β-D-glucose and indoxyl. Oxidation of indoxyl by CYP450 enzymes in the liver or kidneys can convert indoxyl to indirubin (PMID: 11076521). Likewise, exposure to air can convert indoxyl to indirubin. In addition to the mammalian production of minute amounts of indirubin, this chemical can also be recovered in far larger amounts from plants. Historically, indirubin has been extracted from the leaves of certain plants of the Indigofera genus, in particular Indigofera tinctoria. Indigofera plants were commonly grown and used throughout the world for the production of dyes. Indirubin is a chemical constituent of indigo naturalis (also known as qing dai), which has been used for hundreds of years in traditional Chinese medicine. It is produced by collecting the waste products from the bacterial degradation of specific forms of vegetation. Indirubin has shown anti-inflammatory and anti-angiogenesis properties in vitro (PMID: 21207415). It has also been studied for potential use in the treatment of ulcerative colitis (PMID: 23674882).
Indinavir is only found in individuals that have used or taken this drug. It is a potent and specific HIV protease inhibitor that appears to have good oral bioavailability. [PubChem]Indinavir inhibits the HIV viral protease enzyme which prevents cleavage of the gag-pol polyprotein, resulting in noninfectious, immature viral particles.
Indole-3-acetamide, also known as 2-(3-indolyl)acetamide or IAM, belongs to the class of organic compounds known as 3-alkylindoles. 3-Alkylindoles are compounds containing an indole moiety that carries an alkyl chain at the 3-position. Indole-3-acetamide has been detected, but not quantified, in several different foods, such as Alaska wild rhubarbs, lingonberries, butternut squash, pineapples, and agaves. Indole-3-acetamide is also found in the common pea and has been isolated from the etiolated seedlings of the black gram (Phaseolus mungo).
Indole-3-carbinol, also known as 3-indolylcarbinol or 1H-indole-3-methanol, belongs to the class of organic compounds known as 3-alkylindoles. 3-Alkylindoles are compounds containing an indole moiety that carries an alkyl chain at the 3-position. Indole-3-carbinol is a dietary indole present in cruciferous vegetables that has been shown to influence estradiol metabolism in humans and may provide a new chemopreventive approach to estrogen-dependent diseases (PMID:2342128). Indole-3-carbinol is produced by members of the family Cruciferae, particularly members of the genus Brassica (e.g. cabbage, radishes, cauliflower, broccoli, Brussels sprouts, and daikon). Indole-3-carbinol is metabolized into a number of products, including the dimeric 3,3'-diindolylmethane. Both 3,3'-diindolylmethane and indole-3-carbinol are thought to have biological effects. Indole-3-carbinol is a natural chemopreventive compound. It has multiple anticarcinogenic and antitumorigenic properties; it can suppress the proliferation of certain cancer cells, including breast cancer, prostate cancer, endometrial cancer, colon cancer, and leukemic cells (PMID:16634522, 16082211).
Indole-3-carboxaldehyde (IAld or I3A), also known as 3-formylindole or 3-indolealdehyde, belongs to the class of organic compounds known as indoles. Indoles are compounds containing an indole moiety, which consists of a pyrrole ring fused to benzene to form 2,3-benzopyrrole. In humans, I3A is a biologically active metabolite which acts as a receptor agonist at the aryl hydrocarbon receptor in intestinal immune cells. It stimulates the production of interleukin-22 which facilitates mucosal reactivity (PMID:27102537). I3A is a microbially derived tryptophan metabolite produced by Clostridium and Lactobacillus (PMID:30120222, 27102537). I3A has also been found in the urine of patients with untreated phenylketonuria (PMID:5073866). I3A has been detected, but not quantified, in several different foods, such as beans, Brussels sprouts, cucumbers, cereals and cereal products, and white cabbages. This could make I3A a potential biomarker for the consumption of these foods.
Indole-3-carboxylic acid, also known as 3-carboxyindole or 3-indolecarboxylate, belongs to the class of organic compounds known as indolecarboxylic acids and derivatives. Indolecarboxylic acids and derivatives are compounds containing a carboxylic acid group (or a derivative thereof) linked to an indole. Naphthylmethylindoles: Any compound containing a 1H-indol-3-yl-(1-naphthyl)methane structure with substitution at the nitrogen atom of the indole ring by an alkyl, haloalkyl, alkenyl, cycloalkylmethyl, cycloalkylethyl, 1-(N-methyl-2-piperidinyl)methyl, or 2-(4-morpholinyl)ethyl group whether or not further substituted in the indole ring to any extent and whether or not substituted in the naphthyl ring to any extent. One example given is JWH-250. Outside of the human body, indole-3-carboxylic acid has been detected, but not quantified in several different foods, such as brassicas, broccoli, pulses, common beets, and barley. This could make indole-3-carboxylic acid a potential biomarker for the consumption of these foods. Notice the pentyl group substituted onto the nitrogen atom of the indole ring. Note that this definition encompasses only those compounds that have OH groups attached to both the phenyl and the cyclohexyl rings, and so does not include compounds such as O-1871 which lacks the cyclohexyl OH group, or compounds such as JWH-337 or JWH-344 which lack the phenolic OH group.
Indomethacin is a non-steroidal antiinflammatory agent (NSAIA) with antiinflammatory, analgesic and antipyretic activity. Its pharmacological effect is thought to be mediated through inhibition of the enzyme cyclooxygenase (COX), the enzyme responsible for catalyzes the rate-limiting step in prostaglandin synthesis via the arachidonic acid pathway.
Feed additive, catabolic agent.
Irbesartan is an angiotensin receptor blocker (ARB) used mainly for the treatment of hypertension. It competes with angiotensin II for binding at the AT1 receptor subtype. Unlike ACE inhibitors, ARBs do not have the adverse effect of dry cough. The use of ARBs is pending revision due to findings from several clinical trials suggesting that this class of drugs may be associated with a small increased risk of cancer.
Irinotecan is an antineoplastic enzyme inhibitor primarily used in the treatment of colorectal cancer. It is a derivative of camptothecin that inhibits the action of topoisomerase I. Irinotecan prevents religation of the DNA strand by binding to topoisomerase I-DNA complex, and causes double-strand DNA breakage and cell death.
2-Methyl-1-propylamine is found in black elderberry. 2-Methyl-1-propylamine is found in various foodstuffs.
Isoquercitrin is found in alcoholic beverages. Isoquercitrin occurs widely in plants. Isoquercitrin is present in red wine.Isoquercitin can be isolated from mangoes and from Rheum nobile, the Noble rhubarb or Sikkim rhubarb, a giant herbaceous plant native to the Himalaya. Quercetin glycosides are also present in tea. (Wikipedia
Isorhamnetin 3-beta-d-glucoside, also known as isorhamnetin-3-glu, is a member of the class of compounds known as flavonoid-3-o-glycosides. Flavonoid-3-o-glycosides are phenolic compounds containing a flavonoid moiety which is O-glycosidically linked to carbohydrate moiety at the C3-position. Isorhamnetin 3-beta-d-glucoside is slightly soluble (in water) and a very weakly acidic compound (based on its pKa). Isorhamnetin 3-beta-d-glucoside can be synthesized from beta-D-glucose. Isorhamnetin 3-beta-d-glucoside can also be synthesized into isorhamnetin. Isorhamnetin 3-beta-d-glucoside can be found in sea-buckthornberry, which makes isorhamnetin 3-beta-d-glucoside a potential biomarker for the consumption of this food product. Isorhamnetin 3-beta-d-glucoside may be a unique S.cerevisiae (yeast) metabolite.
Isoxanthopterin is a pteridine normally present in plasma, urine, and other bodily fluids also vary from normal concentrations in some disease states and also have diagnostic value. Pteridines' urinary concentrations seem to vary independently from each other and from normal values to yield a pattern of excreted pteridines that is diagnostic for different species, tissues, and tumor types. Intravenous or intramuscular administration of isoxanthopterin inhibits the growth rates of animal tumor models. Pteridin derivatives are a family of organic compound with very similar chemical structures which play an important biochemistry role. Pteridines metabolism and its regulation in normal and pathological conditions have not been extensively investigated due to the difficulty of their quantification. A significant decrease of isoxanthopterin has been determined in cancer patients. (PMID 15837549, 9800651). Xanthine dehydrogenase (XDH) is the enzymes responsible for the conversion of xanthine to uric acid. It requires the presence of the molybdenum cofactor for its proper functioning. XDH is reported to have additional functions, i.e., the conversion of pterin to isoxanthopterin, one of the steps the degradation pathway of 5,6,7,8-tetrahydrobiopterin (BH4). Isoxanthopterin is very low in some cases of hereditary xanthinuria (OMIM 278300) and molybdenum cofactor deficiency (OMIM 252150). (PMID: 8812740).
Isradipine belongs to the dihydropyridine (DHP) class of calcium channel blockers (CCBs), the most widely used class of CCBs. It is structurally related to felodipine, nifedipine, and nimodipine and is the most potent calcium-channel blocking agent of the DHP class. Isradipine binds to calcium channels with high affinity and specificity and inhibits calcium flux into cardiac and arterial smooth muscle cells. It exhibits greater selectivity towards arterial smooth muscle cells owing to alternative splicing of the alpha-1 subunit of the channel and increased prevalence of inactive channels in smooth muscle cells. Isradipine may be used to treat mild to moderate essential hypertension.
Kaempferol 3-rhamno-glucoside, also known as nicotiflorin or kaempferol 3-rutinoside, is a member of the class of compounds known as flavonoid-3-o-glycosides. Flavonoid-3-o-glycosides are phenolic compounds containing a flavonoid moiety which is O-glycosidically linked to carbohydrate moiety at the C3-position. Kaempferol 3-rhamno-glucoside is slightly soluble (in water) and a very weakly acidic compound (based on its pKa). Kaempferol 3-rhamno-glucoside can be found in ginkgo nuts and tea, which makes kaempferol 3-rhamno-glucoside a potential biomarker for the consumption of these food products.
Kaempferol, also known as rhamnolutein or c.i. 75640, belongs to the class of organic compounds known as flavonols. Flavonols are compounds that contain a flavone (2-phenyl-1-benzopyran-4-one) backbone carrying a hydroxyl group at the 3-position. Thus, kaempferol is considered to be a flavonoid molecule. A tetrahydroxyflavone in which the four hydroxy groups are located at positions 3, 5, 7 and 4'. Kaempferol is a very hydrophobic molecule, practically insoluble in water, and relatively neutral. Kaempferol exists in all eukaryotes, ranging from yeast to humans. Kaempferol is a bitter tasting compound. Kaempferol is found, on average, in the highest concentration within a few different foods, such as saffrons, capers, and cumins and in a lower concentration in lovages, endives, and cloves. Kaempferol has also been detected, but not quantified, in several different foods, such as shallots, pine nuts, feijoa, kombus, and chicory leaves. This could make kaempferol a potential biomarker for the consumption of these foods. Kaempferol is a potentially toxic compound.
Ketotifen is only found in individuals that have used or taken this drug. It is a cycloheptathiophene blocker of histamine H1 receptors and release of inflammatory mediators. It has been proposed for the treatment of asthma, rhinitis, skin allergies, and anaphylaxis. [PubChem]Ketotifen is a relatively selective, non-competitive histamine antagonist (H1-receptor) and mast cell stabilizer. Ketotifen inhibits the release of mediators from mast cells involved in hypersensitivity reactions. Decreased chemotaxis and activation of eosinophils have also been demonstrated. Ketotifen also inhibits cAMP phosphodiesterase. Properties of ketotifen which may contribute to its antiallergic activity and its ability to affect the underlying pathology of asthma include inhibition of the development of airway hyper-reactivity associated with activation of platelets by PAF (Platelet Activating Factor), inhibition of PAF-induced accumulation of eosinophils and platelets in the airways, suppression of the priming of eosinophils by human recombinant cytokines and antagonism of bronchoconstriction due to leukotrienes. Ketotifen inhibits of the release of allergic mediators such as histamine, leukotrienes C4 and D4(SRS-A) and PAF.
Kynurenine is a metabolite of the amino acid tryptophan used in the production of niacin. L-Kynurenine is a central compound of the tryptophan metabolism pathway since it can change into the neuroprotective agent kynurenic acid or to the neurotoxic agent quinolinic acid. The break-up of these endogenous compounds' balance can be observable in many disorders such as stroke, epilepsy, multiple sclerosis, and amyotrophic lateral sclerosis. It can also occur in neurodegenerative disorders such as Parkinson's disease, Huntington's, and Alzheimer's disease; and in mental disorders such as schizophrenia and depression.
Lamivudine is only found in individuals that have used or taken this drug. It is a reverse transcriptase inhibitor and zalcitabine analog in which a sulfur atom replaces the 3&#39; carbon of the pentose ring. It is used to treat Human Immunodeficiency Virus Type 1 (HIV-1) and hepatitis B (HBV).Lamivudine is a synthetic nucleoside analogue and is phosphorylated intracellularly to its active 5'-triphosphate metabolite, lamivudine triphosphate (L-TP). This nucleoside analogue is incorporated into viral DNA by HIV reverse transcriptase and HBV polymerase, resulting in DNA chain termination.
Lamotrigine is an anticonvulsant drug used in the treatment of epilepsy and bipolar disorder. For epilepsy it is used to treat partial seizures, primary and secondary tonic-clonic seizures, and seizures associated with Lennox-Gastaut syndrome. Lamotrigine also acts as a mood stabilizer. It is the first medication since lithium granted Food and Drug Administration (FDA) approval for the maintenance treatment of bipolar type I. Chemically unrelated to other anticonvulsants, lamotrigine has relatively few side-effects and does not require blood monitoring. The exact way lamotrigine works is unknown. [Wikipedia]
Latanoprost ophthalmic solution is a topical medication used for controlling the progression of glaucoma or ocular hypertension, by reducing intraocular pressure. It is a prostaglandin analogue that works by increasing the outflow of aqueous fluid from the eyes. It is also known by the brand name of Xalatan manufactured by Pfizer.
Letrozole (INN, trade name Femara) is an oral non-steroidal aromatase inhibitor that has been introduced for the adjuvant treatment of hormonally-responsive breast cancer
An antihelminthic drug that has been tried experimentally in rheumatic disorders where it apparently restores the immune response by increasing macrophage chemotaxis and T-lymphocyte function. Paradoxically, this immune enhancement appears to be beneficial in rheumatoid arthritis where dermatitis, leukopenia, and thrombocytopenia, and nausea and vomiting have been reported as side effects. (From Smith and Reynard, Textbook of Pharmacology, 1991, p435-6)
Levocetirizine is a second-generation piperazine H1-antihistamine. It has also been labeled as a third-generation antihistamine because it is developed from a second-generation antihistamine (cetirizine).
A synthetic progestational hormone with actions similar to those of progesterone and about twice as potent as its racemic or (+-)-isomer (norgestrel). It is used for contraception, control of menstrual disorders, and treatment of endometriosis. It is usually supplied in a racemic mixture (Norgestrel, 6533-00-2). Only the levonorgestrel isomer is active.
Lidocaine is only found in individuals that have used or taken this drug. It is a local anesthetic and cardiac depressant used as an antiarrhythmia agent. Its actions are more intense and its effects more prolonged than those of procaine but its duration of action is shorter than that of bupivacaine or prilocaine. [PubChem]Lidocaine stabilizes the neuronal membrane by inhibiting the ionic fluxes required for the initiation and conduction of impulses thereby effecting local anesthetic action. Lidocaine alters signal conduction in neurons by blocking the fast voltage gated sodium (Na+) channels in the neuronal cell membrane that are responsible for signal propagation. With sufficient blockage the membrane of the postsynaptic neuron will not depolarize and will thus fail to transmit an action potential. This creates the anaesthetic effect by not merely preventing pain signals from propagating to the brain but by aborting their birth in the first place.
Dipentene is found in carrot. Dipentene is a constituent of many essential oils
Linezolid is only found in individuals that have used or taken this drug. It is a synthetic antibiotic, the first of the oxazolidinone class, used for the treatment of infections caused by multi-resistant bacteria including streptococcus and methicillin-resistant Staphylococcus aureus (MRSA). Linezolid is a synthetic antibacterial agent of the oxazolidinone class of antibiotics. It has in vitro activity against aerobic Gram positive bacteria, certain Gram negative bacteria and anaerobic microorganisms. It selectively inhibits bacterial protein synthesis through binding to sites on the bacterial ribosome and prevents the formation of a functional 70S-initiation complex. Specifically, linezolid binds to a site on the bacterial 23S ribosomal RNA of the 50S subunit and prevents the formation of a functional 70S initiation complex, which is an essential component of the bacterial translation process. The results of time-kill studies have shown linezolid to be bacteriostatic against enterococci and staphylococci. For streptococci, linezolid was found to be bactericidal for the majority of strains. Linezolid is also a reversible, nonselective inhibitor of monoamine oxidase. Therefore, linezolid has the potential for interaction with adrenergic and serotonergic agents.
Lipoamide is a trivial name for 6,8-dithiooctanoic amide. It is 6,8-dithiooctanoic acid's functional form where the carboxyl group is attached to protein (or any other amine) by an amide linkage (containing -NH2) to an amino group. Lipoamide forms a thioester bond, oxidizing the disulfide bond, with acetaldehyde (pyruvate after it has been decarboxylated). It then transfers the acetaldehyde group to CoA which can then continue in the TCA cycle. Lipoamide is an intermediate in glycolysis/gluconeogenesis, citrate cycle (TCA cycle), alanine, aspartate and pyruvate metabolism, and valine, leucine and isoleucine degradation (KEGG:C00248). It is generated from dihydrolipoamide via the enzyme dihydrolipoamide dehydrogenase (EC:1.8.1.4) and then converted to S-glutaryl-dihydrolipoamide via the enzyme oxoglutarate dehydrogenase (EC:1.2.4.2).
Liquiritigenin is found in alfalfa. Liquiritigenin is isolated from Glycyrrhiza, Medicago, Myroxylon, Cicer, and all Leguminosae species. Several glycosides, particularly rutinoside and neohesperidoside, are important in influencing citrus fruit flavour.
Lofexidine is an alpha2-adrenergic receptor agonist. It can be used as a short acting anti-hypertensive, but is mostly used to help relieve symptoms of heroin or opiate withdrawal in opiate dependency. It is approved in the United Kingdom, but is still undergoing clinical trials in the United States.
desloratadine is available off the shelf in Canada); Loratadine is a tricyclic antihistamine, which has a selective and peripheral H1-antagonist action. It has a long-lasting effect and does not normally cause drowsiness because it does not readily enter the central nervous system; An antiviral that is used in the prophylactic or symptomatic treatment of influenza A. It is also used as an antiparkinsonian agent, to treat extrapyramidal reactions, and for postherpetic neuralgia. The mechanisms of its effects in movement disorders are not well understood but probably reflect an increase in synthesis and release of dopamine, with perhaps some inhibition of dopamine uptake; Loratadine is a drug used to treat allergies. It is marketed by Schering-Plough under several trade names such as Claritin, Clarityn or Claratyne depending on the market, by Lek as Lomilan and by Wyeth as Alavert. It is also available as a generic; Loratadine is a drug used to treat allergies. It is marketed by Schering-Plough under several trade names such as Claritin, Clarityn or Claratyne depending on the market, by Lek as Lomilan and by Wyeth as Alavert. It is also available as a generic. Its active metabolite, desloratadine, is also on the market, though loratadine itself is the only drug of its class available over the counter (at least in the U.S. as of 2005. Loratadine is available off the shelf in the UK.
Lorazepam is only found in individuals that have used or taken this drug. It is a benzodiazepine used as an anti-anxiety agent with few side effects. It also has hypnotic, anticonvulsant, and considerable sedative properties and has been proposed as a preanesthetic agent. [PubChem]Lorazepam binds to an allosteric site on GABA-A receptors, which are pentameric ionotropic receptors in the CNS. Binding potentiates the effects of the inhibitory neurotransmitter GABA, which upon binding opens the chloride channel in the receptor, allowing chloride influx and causing hyperpolerization of the neuron.
Losartan is an angiotensin-receptor blocker (ARB) that may be used alone or with other agents to treat hypertension. Losartan and its longer acting metabolite, E-3174, lower blood pressure by antagonizing the renin-angiotensin-aldosterone system (RAAS); they compete with angiotensin II for binding to the type-1 angiotensin II receptor (AT1) subtype and prevents the blood pressure increasing effects of angiotensin II. Unlike angiotensin-converting enzyme (ACE) inhibitors, ARBs do not have the adverse effect of dry cough. Losartan may be used to treat hypertension, isolated systolic hypertension, left ventricular hypertrophy and diabetic nephropathy. It may also be used as an alternative agent for the treatment of systolic dysfunction, myocardial infarction, coronary artery disease, and heart failure.
Loxapine is only found in individuals that have used or taken this drug. It is an antipsychotic agent used in schizophrenia. [PubChem]Loxapine is a dopamine antagonist, and also a serotonin 5-HT2 blocker. The exact mode of action of Loxapine has not been established, however changes in the level of excitability of subcortical inhibitory areas have been observed in several animal species in association with such manifestations of tranquilization as calming effects and suppression of aggressive behavior.
As most NSAIDs, loxoprofen is a non-selective cyclooxygenase inhibitor, and works by reducing the synthesis of prostaglandins from arachidonic acid. Loxoprofen (INN) is a non-steroidal anti-inflammatory drug in the propionic acid derivatives group, which also includes ibuprofen and naproxen among others. It is marketed in Brazil, Mexico and Japan by Sankyo as its sodium salt, loxoprofen sodium, under the trade name Loxonin, Argentina as Oxeno and in India as Loxomac. It is available in these countries for oral administration, and a transdermal preparation was approved for sale in Japan on January 2006. Loxoprofen is a prodrug. It is quickly converted to its active trans-alcohol metabolite following oral administration, and reaches its peak plasma concentration within 30 to 50 minutes.
Maltol, also known as E636 or fema 2656, belongs to the class of organic compounds known as pyranones and derivatives. Pyranones and derivatives are compounds containing a pyran ring which bears a ketone. Some synthetic derivatives of maltol, developed at the University of Urbino, showed limited in vitro antiproliferative activity towards cancer cells lines, perhaps inducing apoptosis in these cells. Maltol is a sweet, baked, and bread tasting compound. Maltol has been detected, but not quantified, in several different foods, such as milk and milk products, nuts, soy beans, pepper (c. annuum), and coffee and coffee products. Maltol's sweetness adds to the odor of freshly baked bread, and is used as a flavor enhancer (INS Number 636) in breads and cakes. Related to this property, maltol has been reported to greatly increase aluminum uptake in the body and to increase the oral bioavailability of gallium and iron. Maltol is a naturally occurring organic compound that is used primarily as a flavor enhancer. It is a white crystalline powder that is soluble in hot water, chloroform, and other polar solvents. Maltol is registered as a flavor component in the EU. Maltol, like related 3-hydroxy-4-pyrones such as kojic acid, binds to hard metal centers such as Fe3+, Ga3+, Al3+, and VO2+. It is known in the European E number food additive series as E636. Because it has the odor of cotton candy and caramel, maltol is used to impart a sweet aroma to fragrances.
Maprotiline is a tetracyclic antidepressant with similar pharmacological properties to tricyclic antidepressants (TCAs). Similar to TCAs, maprotiline inhibits neuronal norepinephrine reuptake, possesses some anticholinergic activity, and does not affect monoamine oxidase activity. It differs from TCAs in that it does not appear to block serotonin reuptake. Maprotiline may be used to treat depressive affective disorders, including dysthymic disorder (depressive neurosis) and major depressive disorder. Maprotiline is effective at reducing symptoms of anxiety associated with depression.
Amdinocillin is only found in individuals that have used or taken this drug. It is an amidinopenicillanic acid derivative with broad spectrum antibacterial action. It is poorly absorbed if given orally and is used in urinary infections and typhus. [PubChem]Amdinocillin is a stong and specific antagonist of Penicillin Binding Protein-2 (PBP 2). It is active against gram negative bacteria, preventing cell wall synthesis by inhibiting the activity of PBP2. PBP2 is a peptidoglycan elongation initiating enzyme. Peptidoglycan is a polymer of sugars and amino acids that is the main component of bacterial cell walls.
Medroxyprogesterone, or MP is a progestin (synthetic progestogen). MP is not used medically, as it is over two orders of magnitude less potent than medroxyprogesterone acetate (MPA); a derivative of MP (PMID: 16784762). MP may be formed via the metabolism of MPA. Medroxyprogesterone acetate is used to treat conditions such as absent or irregular menstrual periods, or abnormal uterine bleeding. Synthetic progestogens are widely used to simulate the effects of progesterone; a natural female sex hormone. Progesterone is essential for endometrial receptivity, embryo implantation, and the successful establishment of pregnancy. A low progesterone concentration or an insufficient response to progesterone can cause infertility and pregnancy loss (PMID: 20104424). In addition to progestagenic activity, MP is also a weak antiandrogen in vitro (PMID: 29990947). Medroxyprogesterone is only found in individuals that have used or taken MPA.
Melatonin is a biogenic amine that is found in animals, plants and microbes. Aaron B. Lerner of Yale University is credited for naming the hormone and for defining its chemical structure in 1958. In mammals, melatonin is produced by the pineal gland. The pineal gland is small endocrine gland, about the size of a rice grain and shaped like a pine cone (hence the name), that is located in the center of the brain (rostro-dorsal to the superior colliculus) but outside the blood-brain barrier. The secretion of melatonin increases in darkness and decreases during exposure to light, thereby regulating the circadian rhythms of several biological functions, including the sleep-wake cycle. In particular, melatonin regulates the sleep-wake cycle by chemically causing drowsiness and. lowering the body temperature. Melatonin is also implicated in the regulation of mood,learning and memory, immune activity, dreaming, fertility and reproduction. Melatonin is also an effective antioxidant. Most of the actions of melatonin are mediated through the binding and activation of melatonin receptors. Individuals with autism spectrum disorders(ASD) may have lower than normal levels of melatonin. A 2008 study found that unaffected parents of individuals with ASD also have lower melatonin levels, and that the deficits. were associated with low activity of the ASMT gene, which encodes the last enzyme of melatonin synthesis. Reduced melatonin production has also been proposed as a likely factor in the significantly higher cancer rates in night workers.
Memantine is an amantadine derivative with low to moderate-affinity for NMDA receptors. It is a noncompetitive NMDA receptor antagonist that binds preferentially to NMDA receptor-operated cation channels. It blocks the effects of excessive levels of glutamate that may lead to neuronal dysfunction. It is under investigation for the treatment of Alzheimer's disease, but there has been no clinical support for the prevention or slowing of disease progression.
A local anesthetic that is chemically related to bupivacaine but pharmacologically related to lidocaine. It is indicated for infiltration, nerve block, and epidural anesthesia. Mepivacaine is effective topically only in large doses and therefore should not be used by this route. (From AMA Drug Evaluations, 1994, p168)
A carbamate with hypnotic, sedative, and some muscle relaxant properties, although in therapeutic doses reduction of anxiety rather than a direct effect may be responsible for muscle relaxation. Meprobamate has been reported to have anticonvulsant actions against petit mal seizures, but not against grand mal seizures (which may be exacerbated). It is used in the treatment of anxiety disorders, and also for the short-term management of insomnia but has largely been superseded by the benzodiazepines. (From Martindale, The Extra Pharmacopoeia, 30th ed, p603) Meprobamate is a controlled substance in the U.S.
Mesoridazine is only found in individuals that have used or taken this drug. It is a phenothiazine antipsychotic with effects similar to chlorpromazine. [PubChem]Based upon animal studies, mesoridazine, as with other phenothiazines, acts indirectly on reticular formation, whereby neuronal activity into reticular formation is reduced without affecting its intrinsic ability to activate the cerebral cortex. In addition, the phenothiazines exhibit at least part of their activities through depression of hypothalamic centers. Neurochemically, the phenothiazines are thought to exert their effects by a central adrenergic blocking action.
A synthetic opioid that is used as the hydrochloride. It is an opioid analgesic that is primarily a mu-opioid agonist. It has actions and uses similar to those of morphine. It also has a depressant action on the cough center and may be given to control intractable cough associated with terminal lung cancer. Methadone is also used as part of the treatment of dependence on opioid drugs, although prolonged use of methadone itself may result in dependence. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1082-3)
Methamphetamine is a psychostimulant and sympathomimetic drug. It is a member of the amphetamine group of sympathomimetic amines. Methamphetamine can induce effects such as euphoria, increased alertness and energy, and enhanced self-esteem. It is a scheduled drug in most countries due to its high potential for addiction and abuse.
Methaqualone, also known as optimil or ortonal, belongs to the class of organic compounds known as quinazolines. Quinazolines are compounds containing a quinazoline moiety, which is made up of two fused six-member aromatic rings, a benzene ring and a pyrimidine ring. Methaqualone is a drug which is used for the treatment of insomnia, and as a sedative and muscle relaxant. Methaqualone exists as a solid and is considered to be practically insoluble (in water) and relatively neutral.
Methionine sulfoxide belongs to the class of organic compounds known as l-alpha-amino acids. These are alpha amino acids which have the L-configuration of the alpha-carbon atom. Methionine sulfoxide exists in all living species, ranging from bacteria to humans. Within humans, methionine sulfoxide participates in a number of enzymatic reactions. In particular, methionine sulfoxide can be biosynthesized from L-methionine through its interaction with the enzyme methionine-R-sulfoxide reductase B3. In addition, methionine sulfoxide can be biosynthesized from L-methionine through the action of the enzyme methionine-R-sulfoxide reductase b2, mitochondrial. In humans, methionine sulfoxide is involved in the metabolic disorder called hypermethioninemia.
Methohexital is only found in individuals that have used or taken this drug. It is an intravenous anesthetic with a short duration of action that may be used for induction of anesthesia. [PubChem]Methohexital binds at a distinct binding site associated with a Cl<sup>-</sup> ionopore at the GABA<sub>A</sub> receptor, increasing the duration of time for which the Cl<sup>-</sup> ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged.
Methotrexate is only found in individuals that have used or taken this drug. It is an antineoplastic antimetabolite with immunosuppressant properties. It is an inhibitor of tetrahydrofolate dehydrogenase and prevents the formation of tetrahydrofolate, necessary for synthesis of thymidylate, an essential component of DNA. [PubChem]Methotrexate anti-tumor activity is a result of the inhibition of folic acid reductase, leading to inhibition of DNA synthesis and inhibition of cellular replication. The mechanism involved in its activity against rheumatoid arthritis is not known.
Methoxamine is only found in individuals that have used or taken this drug. It is an alpha-adrenergic agonist that causes prolonged peripheral vasoconstriction. It has little if any direct effect on the central nervous system. [PubChem]Methoxamine acts through peripheral vasoconstriction by acting as a pure alpha-1 adrenergic receptor agonist, consequently increasing systemic blood pressure (both systolic and diastolic).
3-Hydroxy-2-methyl-butanoic acid (HMBA) is a normal urinary metabolite involved in the isoleucine catabolism, as well as presumably beta-oxidation of fatty acids and ketogenesis, excreted in abnormally high amounts in beta-ketothiolase deficiency, which is a genetic disorder. Differences in the enantiomeric ratio of HMBA may originate from the enantioselectivity of different enzyme systems (PMID 10755375).
A synthetic anabolic steroid used for treating men with testosterone deficiency or similar androgen replacement therapies. Also, has antineoplastic properties and so has been used secondarily in women with advanced breast cancer. Methyltestosterone is a schedule III drug in the US.
Tyrosine methylester, also known as Tyrosine methyl ester hydrochloride, (L)-isomer or Tyr-ome, is classified as a tyrosine or a Tyrosine derivative. Tyrosines are compounds containing tyrosine or a derivative thereof resulting from reaction of tyrosine at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom. Tyrosine methylester is considered to be a slightly soluble (in water) and a very weak acidic compound. Tyrosine methylester can be found in humans.
Methyprylon is a sedative of the piperidinedione derivative family. This medicine was used for treating insomnia, but is now rarely used as it has been replaced by newer drugs with less side effects, such as benzodiazepines. Methyprylon was withdrawn from the US market in June 1965 and the Canadian market in September 1990. [Wikipedia]
A nitroimidazole used to treat amebiasis; vaginitis; trichomonas infections; giardiasis; anaerobic bacteria; and treponemal infections. It has also been proposed as a radiation sensitizer for hypoxic cells. According to the Fourth Annual Report on Carcinogens (NTP 85-002, 1985, p133), this substance may reasonably be anticipated to be a carcinogen (Merck, 11th ed).
A short-acting hypnotic-sedative drug with anxiolytic and amnestic properties. It is used in dentistry, cardiac surgery, endoscopic procedures, as preanesthetic medication, and as an adjunct to local anesthesia. The short duration and cardiorespiratory stability makes it useful in poor-risk, elderly, and cardiac patients. It is water-soluble at pH less than 4 and lipid-soluble at physiological pH. [PubChem] Midazolam is a schedule IV drug in the United States.
A progestational and glucocorticoid hormone antagonist. Its inhibition of progesterone induces bleeding during the luteal phase and in early pregnancy by releasing endogenous prostaglandins from the endometrium or decidua. As a glucocorticoid receptor antagonist, the drug has been used to treat hypercortisolism in patients with nonpituitary cushing syndrome. [PubChem]
Miglitol is an oral anti-diabetic drug that acts by inhibiting the ability of the patient to breakdown complex carbohydrates into glucose. It is primarily used in diabetes mellitus type 2 for establishing greater glycemic control by preventing the digestion of carbohydrates (such as disaccharides, oligosaccharides, and polysaccharides) into monosaccharides which can be absorbed by the body. Miglitol inhibits glycoside hydrolase enzymes called alpha-glucosidases. Since miglitol works by preventing digestion of carbohydrates, it lowers the degree of postprandial hyperglycemia. It must be taken at the start of main meals to have maximal effect. Its effect will depend on the amount of non-monosaccharide carbohydrates in a person's diet. In contrast to acarbose (another alpha-glucosidase inhibitor), miglitol is systemically absorbed; however, it is not metabolized and is excreted by the kidneys.
Milnacipran is an antidepressant of the serotonin-norepinephrine reuptake inhibitor class. Milnacipran has been approved and sold in Austria since September 1998 under the brand name Ixel. Cypress Bioscience bought the exclusive rights for approval and marketing of the drug for any purpose in the US and Canada in 2003 from the manufacturer Pierre Fabre; the approval procedure in both countries is ongoing.
Milrinone is only found in individuals that have used or taken this drug. It is a positive inotropic cardiotonic agent with vasodilator properties. Milrinone inhibits erythrocyte phosphodiesterase, resulting in an increase in erythrocyte cAMP activity. Subsequently, the erythrocyte membrane becomes more resistant to deformity. Along with erythrocyte activity, Milrinone also decreases blood viscosity by reducing plasma fibrinogen concentrations and increasing fibrinolytic activity. It also inhibits cAMP phosphodiesterase activity in myocardium and vascular smooth muscle. Milrinone is a derivative of amrinone and has 20-30 times the ionotropic potency of amrinone. [PubChem]
Mirtazapine is an antidepressant introduced by Organon International in 1996 used for the treatment of moderate to severe depression. Mirtazapine has a tetracyclic chemical structure and is classified as a noradrenergic and specific serotonergic antidepressant (NaSSA). It is the only tetracyclic antidepressant that has been approved by the Food and Drug Administration to treat depression. [Wikipedia]
Moclobemide is only found in individuals that have used or taken this drug. It is a reversible monoamine oxidase inhibitor (MAOI) selective for isoform A (RIMA) used to treat major depressive disorder.The mechanism of action of moclobemide involves the selective, reversible inhibition of MAO-A. This inhibition leads to a decrease in the metabolism and destruction of monoamines in the neurotransmitters. This results in an increase in the monoamines, relieving depressive symptoms.
Modafinil is a stimulant drug marketed as a 'wakefulness promoting agent' and is one of the stimulants used in the treatment of narcolepsy. Narcolepsy is caused by dysfunction of a family of wakefulness-promoting and sleep-suppressing peptides, the orexins, whose neurons are activated by modafinil. The prexin neuron activation is associated with psychoactivation and euphoria. The exact mechanism of action is unclear, although in vitro studies have shown it to inhibit the reuptake of dopamine by binding to the dopamine reuptake pump, and lead to an increase in extracellular dopamine. Modafinil activates glutamatergic circuits while inhibiting GABA.
Moxifloxacin is only found in individuals that have used or taken this drug. It is a synthetic fluoroquinolone antibiotic agent. Bayer AG developed the drug (initially called BAY 12-8039) and it is marketed worldwide (as the hydrochloride) under the brand name Avelox (in some countries also Avalox) for oral treatment.The bactericidal action of moxifloxacin results from inhibition of the enzymes topoisomerase II (DNA gyrase) and topoisomerase IV. DNA gyrase is an essential enzyme that is involved in the replication, transcription and repair of bacterial DNA. Topoisomerase IV is an enzyme known to play a key role in the partitioning of the chromosomal DNA during bacterial cell division.
Moxonidine (INN) is a new generation centrally acting antihypertensive drug licensed for the treatment of mild to moderate essential hypertension. It may have a role when thiazides, beta-blockers, ACE inhibitors and calcium channel blockers are not appropriate or have failed to control blood pressure. In addition, it demonstrates favourable effects on parameters of the insulin resistance syndrome, apparently independent of blood pressure reduction. It is manufactured by Solvay Pharmaceuticals under the brand name Physiotens. Moxonidine is a selective agonist at the imidazoline receptor subtype 1 (I1). This receptor subtype is found in both the rostral ventro-lateral pressor and ventromedial depressor areas of the medulla oblongata. Moxonidine therefore causes a decrease in sympathetic nervous system activity and, therefore, a decrease in blood pressure.
Myricetin, also known as cannabiscetin or myricetol, belongs to the class of organic compounds known as flavonols. Flavonols are compounds that contain a flavone (2-phenyl-1-benzopyran-4-one) backbone carrying a hydroxyl group at the 3-position. Thus, myricetin is considered to be a flavonoid lipid molecule. A hexahydroxyflavone that is flavone substituted by hydroxy groups at positions 3, 3', 4', 5, 5' and 7. Myricetin is a very hydrophobic molecule, practically insoluble in water, and relatively neutral. Myricetin is found, on average, in the highest concentration within a few different foods, such as common walnuts, carobs, and fennels and in a lower concentration in welsh onions, yellow bell peppers, and jutes. Myricetin has also been detected, but not quantified in several different foods, such as napa cabbages, sesames, mixed nuts, lichee, and garden cress.
Asymmetric dimethylarginine (ADMA) is a naturally occurring chemical found in blood plasma. It is a metabolic by-product of continual protein modification processes in the cytoplasm of all human cells. It is closely related to L-arginine, a conditionally-essential amino acid. ADMA interferes with L-arginine in the production of nitric oxide, a key chemical to endothelial and hence cardiovascular health. Asymmetric dimethylarginine is created in protein methylation, a common mechanism of post-translational protein modification. This reaction is catalyzed by an enzyme set called S-adenosylmethionine protein N-methyltransferases (protein methylases I and II). The methyl groups transferred to create ADMA are derived from the methyl group donor S-adenosylmethionine, an intermediate in the metabolism of homocysteine. (Homocysteine is an important blood chemical, because it is also a marker of cardiovascular disease). After synthesis, ADMA migrates into the extracellular space and thence into blood plasma. Asymmetric dimethylarginine is measured using high performance liquid chromatography. ADMA has been identified as a uremic toxin according to the European Uremic Toxin Working Group (PMID: 22626821).
N,N-Dimethylformamide (DMF) is a clear liquid that has been widely used in industries as a solvent, an additive, or an intermediate because of its extensive miscibility with water and most common organic solvents. Its health effects include hepatotoxicity and male reproductoxicity, possibly linked with mitochondrial DNA (mtDNA) alterations including mtDNA common deletion (delta-mtDNA4977) and mtDNA copy number; during the biotransformation of DMF in the body, free radicals are formed, including hydroxyl radicals. The world-wide consumption of DMF in 2001 was approximately 285,000 metric tonnes and most of that was used as an industrial solvent. Overexposure to DMF could result in hepatotoxicity, alcohol intolerance, possible embryotoxicity and teratogenicity in humans and animals, and decline of human sperm motility. Based on its wide application and a wide range of toxic effects, DMF has been selected as one of the four priority compounds for human field studies by the National Toxicology Program (NTP) of the US National Institute of Environmental Health Sciences (NIEHS). The current permissible exposure limit for DMF in the working environment is 10 ppm in both USA and Taiwan. The concentrations of two major DMF metabolites in urine, N-methylformamide (U-NMF) of 15 mg/L and N-acetyl-S-(N-methylcarbamoyl) cysteine (U-AMCC) of 40 mg/L, were recommended as the biological exposure indices (BEIs) by the American Conference of Governmental Industrial Hygienists for DMF exposure in workplace. (PMID: 17254560).
Dimethylglycine (DMG) is an amino acid derivative found in the cells of all plants and animals and can be obtained in the diet in small amounts from grains and meat. The human body produces DMG when metabolizing choline into glycine. Dimethylglycine that is not metabolized in the liver is transported by the circulatory system to body tissue. Dimethylglycine was popular with Russian athletes and cosmonauts owing to its reputed ability to increase endurance and reduce fatigue. DMG is also a byproduct of homocysteine metabolism. Homocysteine and betaine are converted to methionine and N,N-dimethylglycine by betaine-homocysteine methyltransferase. DMG in the urine is a biomarker for the consumption of legumes. It is also a microbial metabolite (PMID: 25901889).
2-Furoylglycine is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acyl glycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13) which is an enzyme that catalyzes the chemical reaction:. acyl-CoA + glycine < -- > CoA + N-acylglycine. Dietary studies show that 2-Furoylglycine precursors are of exogenous origin. Most probably from furan derivatives found in food prepared by strong heating. This may explain the absence of 2-furoylglycine in urine of breastfed children (PMID 4630229). 2-Furoylglycine is also a microbial metabolite.
Glycitein is a soy isoflavone. It is a minor component in most soy products. It's role of reducing low-density lipoprotein cholesterol is not clear. Glycitein is metabolized by human gut microorganisms and may follow metabolic pathways similar to other soy isoflavones (PMID: 12011578; 16248547). Glycitein is a biomarker for the consumption of soy beans and other soy products.
N4-Acetylcytidine is a modified nucleoside. N4-acetylcytidine is an endogenous urinary nucleoside product of the degradation of transfer ribonucleic acid (tRNA); urinary nucleosides are biological markers for patients with colorectal cancer. tRNA has been shown to be excreted in abnormal amounts in the urine of cancer patients. tRNA from neoplastic tissue had a much more rapid turnover rate than the tRNA from the corresponding normal tissue. Evidence indicates that methylation of tRNA occurs only after synthesis of the intact macromolecule. Because there are no specific enzyme systems to incorporate the modified nucleosides into the macromolecular nucleic acid, these nucleosides once released in the process of tRNA turnover cannot be reutilized, nor are they further degraded, but are excreted in urine. (PMID: 15991285, 3506820).
N-Acetyl-D-Glucosamine (N-acetlyglucosamine) is a monosaccharide derivative of glucose. Chemically it is an amide between glucosamine and acetic acid. A single N-acetlyglucosamine moiety linked to serine or threonine residues on nuclear and cytoplasmic proteins -O-GlcNAc, is an ubiquitous post-translational protein modification. O-GlcNAc modified proteins are involved in sensing the nutrient status of the surrounding cellular environment and adjusting the activity of cellular proteins accordingly. O-GlcNAc regulates cellular responses to hormones such as insulin, initiates a protective response to stress, modulates a cell's capacity to grow and divide, and regulates gene transcription. In humans, it exists in skin, cartilage and blood vessel as a component of hyaluronic acid, and bone tissue, cornea and aorta as a component of keratan sulfate. (PMID 16237703).
N-Methylhistamine belongs to the class of organic compounds known as aralkylamines. These are alkylamines in which the alkyl group is substituted at one carbon atom by an aromatic hydrocarbyl group.
Cinnamoylglycine is known as a urinary metabolite in man (PMID 649712) although whether it is formed de novo from plant cinnamate or is a plant product excreted. unchanged has not been conclusively demonstrated. When cinnamoylglycine occurs naturally it is probably a food constituent excreted unchanged. It is not found when small quantities (0.5-6 g) of cinnamic acid are fed to man, but by analogy with animal experiments may be produced when much larger quantities are given. (PMID 6743769).
N-formyl-L-methionine is a L-methionine derivative in which one of the hydrogens attached to the nitrogen is replaced by a formyl group. It has a role as a metabolite. It is a proteinogenic amino acid, a N-formyl amino acid and a L-methionine derivative. It is a conjugate acid of a N-formyl-L-methioninate. N-Formyl-L-methionine belongs to the class of organic compounds known as methionine and derivatives. Methionine and derivatives are compounds containing methionine or a derivative thereof resulting from reaction of methionine at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom. N-Formyl-L-methionine is effective in the initiation of protein synthesis. The initiating methionine residue enters the ribosome as N-formylmethionyl-tRNA. This process occurs in Escherichia coli and other bacteria as well as in the mitochondria of eukaryotic cells.
Acetyl-N-formyl-5-methoxykynurenamine (AFMK) results from the oxidative cleavage of the pyrrole ring during melatonin oxidation by myeloperoxidase (MPO), a superoxide anion (O)-dependent reaction. AFMK is also expected to be formed from oxidation catalyzed by the unspecific enzyme indoleamine-2,3-dioxygenase (IDO), found in a variety of cell types including monocyte/macrophage lineages. MPO- and IDO-catalyzed melatonin oxidation has the requirement of O in common, a species formed in large amounts in inflammatory conditions. The non-enzymatic formation of AFMK can also be expected by its direct reaction with highly reactive oxygen species, such as hydroxyl radical and singlet oxygen. Thus, we assume that AFMK is a product formed in a route of melatonin metabolism, especially active in inflammation. As AFMK is biologically more active on leukocytes than melatonin, the metabolizing of melatonin to AFMK at inflammatory sites possibly plays a role in immunomodulation. AFMK is found in the CSF of patients with meningitis, and in some samples at a remarkably high concentration. AFMK was also found in some patients to exceed the concentration of melatonin normally found in serum (PMID: 16150112).
Isobutyrylglycine is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acyl glycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13) which is an enzyme that catalyzes the chemical reaction: acyl-CoA + glycine < -- > CoA + N-acylglycine. Isobutyrylglycine is identified in large amount in urine of patients with isobutyryl-CoA dehydrogenase deficiency. Isobutyryl-CoA dehydrogenase deficiency is a disorder caused by the deficiency of isobutyryl-CoA dehydrogenase that is involved in the catabolism of the branched-chain amino acid valine (PMID 15505379). Moreover, Isobutyrylglycine is found to be associated with ethylmalonic encephalopathy and propionic acidemia, which are also inborn errors of metabolism. Isobutyrylglycine is a biomarker for the consumption of cheese.
Isovalerylglycine (IVG) is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acyl glycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13) which is an enzyme that catalyzes the chemical reaction: acyl-CoA + glycine < -- > CoA + N-acylglycine. Isovalerylglycine is a byproduct of the catabolism of the aminoacid leucine. Accumulation of isovalerylglycine occurs in Isovaleric Acidemia (IVA). IVA (OMIM/ McKusick 243500) is an autosomal recessive disorder caused by mutations in the isovaleryl-CoA dehydrogenase (EC 1.3.99.10) gene. The deficiency of this enzyme in the metabolism of leucine leads to the accumulation of a series of isovaleryl-CoA metabolites, such as isovalerylglycine. It is very important to caution for false positive results when screening for isovaleric acidemia by tandem mass spectrometry based on dried blood-spot levels of C5-acylcarnitines, including isovalerylcarnitine and its isomer, pivaloylcarnitine; pivaloylcarnitine is derived from pivalate-generating antibiotics, and has caused many false-positive results (PMID: 17850781). Isovalerylglycine is a biomarker for the consumption of cheese.
2-(Methylamino)benzoic acid is found in citrus. 2-(Methylamino)benzoic acid is isolated from grapefruit peel oi
N-Methyl-L-proline, also known as N-methyl-L-proline, (2S)-1-methylpyrrolidine-2-carboxylic acid, hydric acid, or monomethyl proline, is classified as a proline or a proline derivative. It is not naturally produced by humans and can only be obtained from the diet. In particular, it is a metabolically inert cell protectant found in many plants and is used by plants to protect against extremes in osmolarity and growth temperatures. N-Methyl-L-proline is found in the fruit juices of yellow orange, blood orange, lemon, mandarin, and bitter orange (PMID: 21838291).
N-Acetylhistamine is a 4-(beta-Acetylaminoethyl)imidazole that is an intermediate in Histidine metabolism. It is generated from Histamine via the enzyme Transferases (EC 2.3.1.-). Histamine is an amine derived by enzymatic decarboxylation of histidine. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter.
N2,N2-Dimethylguanosine is an urinary nucleoside, a primary degradation product of tRNA. The mean levels of urinary N2,N2-Dimethylguanosine in the patients with colorectal cancer are significantly higher than those in patients with intestinal villous adenoma or the healthy adults (PMID 15991285). N2,N2-Dimethylguanosine has been identified in the human placenta (PMID: 32033212).
2-Methylguanosine is an endogenous methylated nucleoside found in human fluids; methylated purine bases are present in higher amounts in tumor-bearing patients compared to healthy controls.DNA hypermethylation is a common finding in malignant cells and has been explored as a therapeutic target for hypomethylating agents. When chemical bonds to DNA, the DNA becomes damaged and proper and complete replication cannot occur to make the normal intended cell. A DNA adduct is an abnormal piece of DNA covalently-bonded to a cancer-causing chemical. This has shown to be the start of a cancerous cell, or carcinogenesis. DNA adducts in scientific experiments are used as bio-markers and as such are themselves measured to reflect quantitatively, for comparison, the amount of cancer in the subject. (PMID: 17336316, 17154124, 3506820, 17044778, 17264127).
Riboprine, also known as isopentenyladenosine or ipa, is a member of the class of compounds known as purine nucleosides. Purine nucleosides are compounds comprising a purine base attached to a ribosyl or deoxyribosyl moiety. Riboprine is slightly soluble (in water) and a very weakly acidic compound (based on its pKa). Riboprine can be found in a number of food items such as peppermint, chinese mustard, custard apple, and green bean, which makes riboprine a potential biomarker for the consumption of these food products.
N6-Methyladenosine is a methylated adenine residue. N6-Methyladenosine is an endogenous urinary nucleoside product of the degradation of transfer ribonucleic acid (tRNA); urinary nucleosides are biological markers for patients with colorectal cancer. tRNA has been shown to be excreted in abnormal amounts in the urine of cancer patients. tRNA from neoplastic tissue had a much more rapid turnover rate than the tRNA from the corresponding normal tissue. Evidence indicates that methylation of tRNA occurs only after synthesis of the intact macromolecule. Because there are no specific enzyme systems to incorporate the modified nucleosides into the macromolecular nucleic acid, these nucleosides once released in the process of tRNA turnover cannot be reutilized, nor are they further degraded, but are excreted in urine. (PMID: 15991285, 3506820).
N8-Acetylspermidine is a polyamine. The polyamines, found in virtually all living organisms, are a ubiquitous group of compounds that appear to play a vital role in many cellular processes involving nucleic acids including cell growth and differentiation. Acetylation on the terminal nitrogen adjacent to the 4-carbon chain produces N8-acetylspermidine. This reaction is catalyzed by spermidine N8-acetyltransferase and does not result in the conversion of spermidine to putrescine. Instead, the product undergoes deacetylation. This acetyltransferase appears to be associated with chromatin in the cell nucleus and has been reported to be the same as (or related to) the enzyme(s) responsible for histone acetylation. N8-Acetylspermidine does not accumulate in tissues but rather appears to be rapidly deacetylated back to spermidine by a relatively specific cytosolic deacetylase, N8-acetylspermidine deacetylase. The function of this N8-acetylation/deacetylation pathway in cellular processes is not understood clearly, but several observations have suggested a role in cell growth and differentiation (PMID: 12093478).
Nalbuphine is only found in individuals that have used or taken this drug. It is a narcotic used as a pain medication. It appears to be an agonist at kappa opioid receptors and an antagonist or partial agonist at mu opioid receptors. [PubChem]The exact mechanism of action is unknown, but is believed to interact with an opiate receptor site in the CNS (probably in or associated with the limbic system). The opiate antagonistic effect may result from competitive inhibition at the opiate receptor, but may also be a result of other mechanisms. Nalbuphine is thought primarily to be a kappa agonist. It is also a partial mu antagonist analgesic, with some binding to the delta receptor and minimal agonist activity at the sigma receptor.
Nandrolone is a C18 steroid with androgenic and anabolic properties. It is generally prepared from alkyl ethers of estradiol to resemble testosterone, but it has one less carbon atom at the 19 position (Pubchem). Nandrolone is an anabolic steroid occurring naturally in the human body, albeit in small quantities. Nandrolone is most commonly sold commercially as its decanoate ester (Deca-Durabolin) and less commonly as a phenylpropionate ester (Durabolin). Nandrolone use is indirectly detectable in urine tests by testing for the presence of 19-norandrosterone, a metabolism product of this molecule. The International Olympic Committee has set a limit of 2 ng per ml of urine as the upper limit, beyond which an athlete is suspected of doping (Wikipedia).
Naproxen (INN) is a non-steroidal anti-inflammatory drug (NSAID) commonly used for the reduction of mild to moderate pain, fever, inflammation and stiffness caused by conditions such as osteoarthritis, rheumatoid arthritis, psoriatic arthritis, gout, ankylosing spondylitis, injury (like fractures), menstrual cramps, tendonitis, bursitis, and the treatment of primary dysmenorrhea. Naproxen and naproxen sodium are marketed under various trade names including: Aleve, Anaprox, Naprogesic, Naprosyn, Naprelan; Naproxen is a non-steroidal anti-inflammatory drug (NSAID) commonly used for the reduction of mild to moderate pain, fever, inflammation and stiffness caused by conditions such as osteoarthritis, rheumatoid arthritis, psoriatic arthritis, gout, ankylosing spondylitis, injury (like fractures), menstrual cramps, tendonitis, bursitis, and the treatment of primary dysmenorrhea. Naproxen and naproxen sodium are marketed under various trade names including: Aleve, Anaprox, Naprogesic, Naprosyn, Naprelan. Naproxen was first marketed as the prescription drug Naprosyn in 1976 and naproxen sodium was first marketed under the trade name Anaprox in 1980. It remains a prescription-only drug in much of the world. The U.S. Food and Drug Administration (FDA) approved the use of naproxen sodium as an over-the-counter (OTC) drug in 1991, where OTC preparations are sold under the trade name Aleve. In Australia, small packets of lower-strength preparations of naproxen sodium are Schedule 2 Pharmacy Medicines; Naproxen is a member of the 2-arylpropionic acid (profen) family of NSAIDs. It is an odorless, white to off-white crystalline substance. It is lipid-soluble, practically insoluble in water with a low pH (below pH 4), while freely soluble in water at 6 pH and above. Naproxen has a melting point of 153 degree centigrade.
Naringin, also known as naringoside or naringin hydrate, is a flavanone-7-O-glycoside between the flavanone naringenin and the disaccharide neohesperidose. Naringin belongs to the flavonoid family. Flavonoids consist of 15 carbon atoms in 3 rings, 2 of which must be benzene rings connected by a 3 carbon chain.  Naringin contains the basic flavonoid structure along with one rhamnose and one glucose unit attached to its aglycone portion, called naringenin, at the 7-carbon position. The steric hindrance provided by the two sugar units makes naringin less potent than its aglycone counterpart, naringenin. Naringin is a bitter tasting compound. Naringin is found, on average, in the highest concentration within a few different foods, such as rosemaries, grapefruit/pummelo hybrids, and grapefruits and in a lower concentration in grape wines, pummelo, and beers. Naringin has also been detected, but not quantified in several different foods, such as citrus, limes, herbs and spices, common oregano, and mandarin orange (clementine, tangerine). Both naringin and hesperetin, which are the aglycones of naringin and hesperidin, occur naturally in citrus fruits. Naringin is the major flavonoid glycoside in grapefruit and gives grapefruit juice its bitter taste. Narinigin exerts a variety of pharmacological effects such as antioxidant activity, blood lipid-lowering, anticarcinogenic activity, and inhibition of selected cytochrome P450 enzymes including CYP3A4 and CYP1A2, which may result in several drug interactions in-vitro.
Nefazodone hydrochloride (trade name Serzone) is an antidepressant drug marketed by Bristol-Myers Squibb. Its sale was discontinued in 2003 in some countries, due to the small possibility of hepatic (liver) injury, which could lead to the need for a liver transplant, or even death. The incidence of severe liver damage is approximately 1 in 250,000 to 300,000 patient-years. On May 20, 2004, Bristol-Myers Squibb discontinued the sale of Serzone in the United States. [Wikipedia]
Nelfinavir is only found in individuals that have used or taken this drug. It is a potent HIV-1 protease inhibitor. It is used in combination with other antiviral drugs in the treatment of HIV in both adults and children. [PubChem]Nelfinavir inhibits the HIV viral proteinase enzyme which prevents cleavage of the gag-pol polyprotein, resulting in noninfectious, immature viral particles.
Niacinamide, also known as nicotinamide (NAM), is a form of vitamin B3 found in food and used as a dietary supplement and medication. Niacinamide belongs to the class of organic compounds known as nicotinamides. These are heterocyclic aromatic compounds containing a pyridine ring substituted at position 3 by a carboxamide group. Its primary significance is in the prevention and/or cure of blacktongue and pellagra. The structure of nicotinamide consists of a pyridine ring to which a primary amide group is attached in the meta position. It is an amide of nicotinic acid. As an aromatic compound, it undergoes electrophilic substitution reactions and transformations of its two functional groups. Niacinamide and phosphoribosyl pyrophosphate can be converted into nicotinic acid mononucleotide and phosphate by the enzyme nicotinamide phosphoribosyltransferase. In humans, niacinamide is involved in the metabolic disorder called the nad+ signalling pathway (cancer). Niacinamide is an odorless tasting compound. Outside of the human body, niacinamide is found, on average, in the highest concentration within a few different foods, such as common sages, cow milk, and cocoa beans and in a lower concentration in common pea. Niacinamide has also been detected, but not quantified in several different foods, such as yardlong beans, roselles, apples, oyster mushrooms, and swiss chards. Niacinamide occurs in trace amounts mainly in meat, fish, nuts, and mushrooms, as well as to a lesser extent in some vegetables. It is commonly added to cereals and other foods. Many multivitamins contain 20–30 mg of vitamin B3 and it is also available in higher doses. Most animals cannot manufacture this compound in amounts sufficient to prevent nutritional deficiency and it therefore must be supplemented through dietary intake.
Nicotinic acid, also known as niacin or vitamin B3, is a water-soluble vitamin whose derivatives such as NADH, NAD, NAD+, and NADP play essential roles in energy metabolism in the living cell and DNA repair. The designation vitamin B3 also includes the amide form, nicotinamide or niacinamide. Severe lack of niacin causes the deficiency disease pellagra, whereas a mild deficiency slows down the metabolism decreasing cold tolerance. The recommended daily allowance of niacin is 2-12 mg a day for children, 14 mg a day for women, 16 mg a day for men, and 18 mg a day for pregnant or breast-feeding women. It is found in various animal and plant tissues and has pellagra-curative, vasodilating, and antilipemic properties. The liver can synthesize niacin from the essential amino acid tryptophan, but the synthesis is extremely slow and requires vitamin B6; 60 mg of tryptophan are required to make one milligram of niacin. Bacteria in the gut may also perform the conversion but are inefficient.
Nicotinuric acid is an acylglycine. Acylglycines are normally minor metabolites of fatty acids. However, the excretion of certain acylglycines is increased in several inborn errors of metabolism. In certain cases, the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acylglycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13) which is an enzyme that catalyzes the chemical reaction acyl-CoA + glycine <-> CoA + N-acylglycine. Nicotinuric acid is the major detoxification product of nicotinic acid. It may serve as a simple quantitative index of hepatic biotransformation of nicotinic acid (PMID:3243933).
Nifedipine has been formulated as both a long- and short-acting 1,4-dihydropyridine calcium channel blocker. It acts primarily on vascular smooth muscle cells by stabilizing voltage-gated L-type calcium channels in their inactive conformation. By inhibiting the influx of calcium in smooth muscle cells, nifedipine prevents calcium-dependent myocyte contraction and vasoconstriction. A second proposed mechanism for the drug's vasodilatory effects involves pH-dependent inhibition of calcium influx via inhibition of smooth muscle carbonic anhydrase. Nifedipine is used to treat hypertension and chronic stable angina.
Nimodipine is a 1,4-dihydropyridine calcium channel blocker. It acts primarily on vascular smooth muscle cells by stabilizing voltage-gated L-type calcium channels in their inactive conformation. By inhibiting the influx of calcium in smooth muscle cells, nimodipine prevents calcium-dependent smooth muscle contraction and subsequent vasoconstriction. Compared to other calcium channel blocking agents, nimodipine exhibits greater effects on cerebral circulation than on peripheral circulation. Nimodipine is used to as an adjunct to improve the neurologic outcome following subarachnoid hemorrhage from ruptured intracranial aneurysm.
Nitazoxanide, also known by the brand name Alinia, is a synthetic nitrothiazolyl-salicylamide derivative and an anti-protozoal agent. It is approved for treatment of infectious diarrhea caused by Cryptosporidium parvum and Giardia lamblia in patients 1 year of age and older. Following oral administration it is rapidly hydrolyzed to its active metabolite, tizoxanide, which is 99% protein bound. Peak concentrations are observed 1-4 hours after administration. It is excreted in the urine, bile and feces. Untoward effects include abdominal pain, vomiting and diarrhea. [Wikipedia]
Nitrazepam is only found in individuals that have used or taken this drug. It is a benzodiazepine derivative used as an anticonvulsant and hypnotic.Nitrazepam belongs to a group of medicines called benzodiazepines. It acts on benzodiazepine receptors in the brain which are associated with the GABA receptors causing an enhanced binding of GABA (gamma amino butyric acid) to GABAA receptors. GABA is a major inhibitory neurotransmitter in the brain, involved in inducing sleepiness, muscular relaxation and control of anxiety and fits, and slows down the central nervous system. The anticonvulsant properties of nitrazepam and other benzodiazepines may be in part or entirely due to binding to voltage-dependent sodium channels rather than benzodiazepine receptors. Sustained repetitive firing seems to be limited by benzodiazepines effect of slowing recovery of sodium channels from inactivation.
Nitrendipine is only found in individuals that have used or taken this drug. It is a calcium channel blocker with marked vasodilator action. It is an effective antihypertensive agent and differs from other calcium channel blockers in that it does not reduce glomerular filtration rate and is mildly natriuretic, rather than sodium retentive. [PubChem]By deforming the channel, inhibiting ion-control gating mechanisms, and/or interfering with the release of calcium from the sarcoplasmic reticulum, Nitrendipine inhibits the influx of extracellular calcium across the myocardial and vascular smooth muscle cell membranes The decrease in intracellular calcium inhibits the contractile processes of the myocardial smooth muscle cells, causing dilation of the coronary and systemic arteries, increased oxygen delivery to the myocardial tissue, decreased total peripheral resistance, decreased systemic blood pressure, and decreased afterload.
Nizatidine is only found in individuals that have used or taken this drug. It is a histamine H2 receptor antagonist with low toxicity that inhibits gastric acid secretion. The drug is used for the treatment of duodenal ulcers. [PubChem]Nizatidine competes with histamine for binding at the H<sub>2</sub>-receptors on the gastric basolateral membrane of parietal cells. Competitive inhibition results in reduction of basal and nocturnal gastric acid secretions. The drug also decreases the gastric acid response to stimuli such as food, caffeine, insulin, betazole, or pentagastrin.
Nobiletin is found in citrus. Nobiletin is isolated from peel of king orange (Citrus nobilis), seville orange (Citrus aurantium) and other Citrus species, and the round kumquat (Fortunella japonica
L-Norleucine, also known as L-aminohexanoate or caprine, belongs to the class of organic compounds known as l-alpha-amino acids. These are alpha amino acids which have the L-configuration of the alpha-carbon atom. Thus, L-norleucine is considered to be a fatty acid lipid molecule. An unnatural amino acid that is used experimentally to study protein structure and function. L-Norleucine is a very hydrophobic molecule, practically insoluble in water, and relatively neutral. L-Norleucine exists in all eukaryotes, ranging from yeast to humans. Outside of the human body, L-Norleucine has been detected, but not quantified in cow milk. This could make L-norleucine a potential biomarker for the consumption of these foods. It binds reversibly to the kringle domain of plasminogen and blocks the binding of plasminogen to fibrin and its activation to plasmin.
Nornicotine is an alkaloid extracted from tobacco and related to nicotine but having a lower toxicity: used as an agricultural and horticultural insecticide.
(-)-alpha-Narcotine is found in opium poppy. (-)-alpha-Narcotine is an alkaloid from Papaver somniferum (opium poppy).Noscapine (also known as Narcotine, Nectodon, Nospen, and Anarcotine) is a benzylisoquinoline alkaloid from plants of the Papaveraceae family, without significant painkilling properties. This agent is primarily used for its antitussive (cough-suppressing) effects. It has also been shown to have anticancer activity. (Wikipedia).
O-Acetylserine is an α-amino acid with the chemical formula HO2CCH(NH2)CH2OC(O)CH3. It is an intermediate in the biosynthesis of the common amino acid cysteine in bacteria and plants. O-Acetylserine is biosynthesized by acetylation of the serine by the enzyme serine transacetylase. The enzyme O-acetylserine (thiol)-lyase, using sulfide sources, converts this ester into cysteine, releasing acetate. O-Acetylserine belongs to the class of organic compounds known as l-alpha-amino acids. These are alpha amino acids which have the L-configuration of the alpha-carbon atom. O-Acetylserine (OASS) is an acylated amino acid derivative. O-Acetylserine exists in all living species, ranging from bacteria to humans. Outside of the human body, O-Acetylserine has been detected, but not quantified in several different foods, such as okra, vaccinium (blueberry, cranberry, huckleberry), rapes, sparkleberries, and lingonberries. This could make O-acetylserine a potential biomarker for the consumption of these foods.
Octanal, also known as 1-caprylaldehyde or aldehyde C-8, belongs to the class of organic compounds known as medium-chain aldehydes. These are an aldehyde with a chain length containing between 6 and 12 carbon atoms. Thus, octanal is considered to be a fatty aldehyde lipid molecule. A saturated fatty aldehyde formally arising from reduction of the carboxy group of caprylic acid (octanoic acid). Octanal is a very hydrophobic molecule, practically insoluble in water, and relatively neutral. Octanal exists in all eukaryotes, ranging from yeast to humans. Octanal is an aldehydic, citrus, and fat tasting compound. Octanal is commonly found in high concentrations in limes, caraway, and mandarin orange (clementine, tangerine) and in lower concentrations in wild carrots and carrots. Octanal has also been detected, but not quantified in several different foods, such as cherry tomato, brussel sprouts, alaska wild rhubarbs, sweet marjorams, and sunflowers.
1-Octanol, also known as octan-1-ol, is the organic compound with the molecular formula CH3(CH2)7OH. It is a fatty alcohol. Many other isomers are also known generically as octanols. Octanol is mainly produced industrially by the oligomerization of ethylene using triethylaluminium followed by oxidation of the alkylaluminium products. This route is known as the Ziegler alcohol synthesis. Octanol also occurs naturally in the form of esters in some essential oils. Octanol and water are immiscible. The distribution of a compound between water and octanol is used to calculate the partition coefficient (logP) of that molecule. Water/octanol partitioning is a good approximation of the partitioning between the cytosol and lipid membranes of living systems. Octanol is a colorless, slightly viscous liquid used as a defoaming or wetting agent. It is also used as a solvent for protective coatings, waxes, and oils, and as a raw material for plasticizers. It is also one of many compounds derived from tobacco and tobacco smoke and shown to increase the permeability of the membranes of human lung fibroblasts (PMID 7466833).
Olmesartan is an antihypertensive agent which belongs to the class of medicines called angiotensin II receptor antagonists. It acts rapidly to lower high blood pressure. It is marketed worldwide by Daiichi Sankyo, Ltd. and in the United States by Daiichi Sankyo, Inc. and Forest Laboratories.
Used to treat allergic conjunctivitis (itching eyes), olopatadine inhibits the release of histamine from mast cells. It is a relatively selective histamine H1 antagonist that inhibits the in vivo and in vitro type 1 immediate hypersensitivity reaction including inhibition of histamine induced effects on human conjunctival epithelial cells.
Omeprazole is a highly effective inhibitor of gastric acid secretion used in the therapy of stomach ulcers, dyspepsia, peptic ulcer disease , gastroesophageal reflux disease and Zollinger-Ellison syndrome. The drug inhibits the H(+)-K(+)-ATPase (H(+)-K(+)-exchanging ATPase) in the proton pump of Gastric Parietal Cells.--Pubchem. Omeprazole is one of the most widely prescribed drugs internationally and is available over the counter in some countries.
Ondansetron is a well tolerated drug with few side effects. Headache, constipation, and dizziness are the most commonly reported side effects associated with its use. There have been no significant drug interactions reported with this drugs use. It is broken down by the hepatic cytochrome P450 system and it has little effect on the metabolism of other drugs broken down by this system; Ondansetron is a serotonin 5-HT3 receptor antagonist used mainly to treat nausea and vomiting following chemotherapy. Its effects are thought to be on both peripheral and central nerves. One part is to reduce the activity of the vagus nerve, which is a nerve that activates the vomiting center in the medulla oblongata, the other is a blockage of serotonin receptors in the chemoreceptor trigger zone. It does not have much effect on vomiting due to motion sickness. This drug does not have any effect on dopamine receptors or muscarinic receptors; A competitive serotonin type 3 receptor antagonist. It is effective in the treatment of nausea and vomiting caused by cytotoxic chemotherapy drugs, including cisplatin, and has reported anxiolytic and neuroleptic properties; Ondansetron (INN) is a serotonin 5-HT3 receptor antagonist used mainly to treat nausea and vomiting following chemotherapy. Its effects are thought to be on both peripheral and central nerves. One part is to reduce the activity of the vagus nerve, which is a nerve that activates the vomiting center in the medulla oblongata, the other is a blockage of serotonin receptors in the chemoreceptor trigger zone. It does not have much effect on vomiting due to motion sickness. This drug does not have any effect on dopamine receptors or muscarinic receptors.
Orlistat is a drug designed to treat obesity. Its primary function is preventing the absorption of fats from the human diet, thereby reducing caloric intake. Orlistat works by inhibiting pancreatic lipase, an enzyme that breaks down triglycerides in the intestine. Without this enzyme, triglycerides from the diet are prevented from being hydrolyzed into absorbable free fatty acids and are excreted undigested.
Oxaprozin is only found in individuals that have used or taken this drug. It is a non-narcotic, non-steroidal anti-inflammatory drug (NSAID), used to relieve the inflammation, swelling, stiffness, and joint pain associated with osteoarthritis and rheumatoid arthritis.Anti-inflammatory effects of Oxaprozin are believed to be due to inhibition of cylooxygenase in platelets which leads to the blockage of prostaglandin synthesis. Antipyretic effects may be due to action on the hypothalamus, resulting in an increased peripheral blood flow, vasodilation, and subsequent heat dissipation. Oxaprozin is a non-selective NSAID, with a cell assay system showing lower COX-2 selectivity implying higher COX-1 selectivity.
Oxazepam is only found in individuals that have used or taken this drug. It is an intermediate-acting benzodiazepine used to treat alcohol withdrawal and anxiety disorders. It is a metabolite of diazepam, prazepam, temazepam, and clorazepate, and has moderate amnesic, anxiolytic, anticonvulsant, hypnotic, sedative, and skeletal muscle relaxant properties compared to other benzodiazepines (Wikipedia). Like other benzodiazepines, oxazepam exerts its anxiolytic effects by potentiating the effect of gamma-aminobutyric acid (GABA) on GABA-A receptors through a cooperative mechanism of action. GABA receptors are ionotropic chloride-linked channel receptors that produce inhibitory postsynaptic potentials. When activated by GABA, the GABA receptor/chloride ionophore complex undergoes a conformational change that allows the passage of chloride ions through the channel. Benzodiazepines are believed to exert their effect by increasing the effect of GABA at its receptor. Benzodiazepine binding increases chloride conductance in the presence of GABA by increasing the frequency at which the channel opens. In contrast, barbiturates increase chloride conductance in the presence of GABA by prolonging the time in which the channel remains open. There are 18 subtypes of the GABA receptor subunits. The &alpha;<sub>2</sub> subunit of the &alpha;<sub>2</sub>&beta;<sub>3</sub>&gamma;<sub>2</sub> receptor complex is thought to mediate anxiolytic effects while the &alpha;<sub>1</sub> subunit of the &alpha;<sub>1</sub>&beta;<sub>2</sub>&gamma;<sub>2</sub> receptor complex is thought to mediate sedative, anticonvulsant, and anterograde amnesia effects.
Oxycodone is only found in individuals that have used or taken this drug. It is a semisynthetic derivative of codeine that acts as a narcotic analgesic more potent and addicting than codeine. [PubChem]Oxycodone acts as a weak agonist at mu, kappa, and delta opioid receptors within the central nervous system (CNS). Oxycodone primarily affects mu-type opioid receptors, which are coupled with G-protein receptors and function as modulators, both positive and negative, of synaptic transmission via G-proteins that activate effector proteins. Binding of the opiate stimulates the exchange of GTP for GDP on the G-protein complex. As the effector system is adenylate cyclase and cAMP located at the inner surface of the plasma membrane, opioids decrease intracellular cAMP by inhibiting adenylate cyclase. Subsequently, the release of nociceptive neurotransmitters such as substance P, GABA, dopamine, acetylcholine, and noradrenaline is inhibited. Opioids such as oxycodone also inhibit the release of vasopressin, somatostatin, insulin, and glucagon. Opioids close N-type voltage-operated calcium channels (kappa-receptor agonist) and open calcium-dependent inwardly rectifying potassium channels (mu and delta receptor agonist). This results in hyperpolarization and reduced neuronal excitability.
An opioid analgesic with actions and uses similar to those of morphine, apart from an absence of cough suppressant activity. It is used in the treatment of moderate to severe pain, including pain in obstetrics. It may also be used as an adjunct to anesthesia. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1092)
4-(Dimethylamino)azobenzene is formerly used as a food dye, use discontinued.Methyl yellow, or C.I. 11020, is a chemical compound which may be used as a pH indicator. In aqueous solution at low pH, methyl yellow appears red. Between pH 2.9 and 4.0, methyl yellow undergoes a transition, to become yellow above pH 4.0. As "butter yellow" the agent had been used as a food additive before its toxicity was recognized (Opie EL). (Wikipedia
p-Anisic acid, also known as 4-anisate or draconic acid, belongs to the class of organic compounds known as p-methoxybenzoic acids and derivatives. These are benzoic acids in which the hydrogen atom at position 4 of the benzene ring is replaced by a methoxy group. p-Anisic acid is a drug. p-Anisic acid exists in all eukaryotes, ranging from yeast to humans. p-Anisic acid is a faint, sweet, and cadaverous tasting compound. Outside of the human body, p-anisic acid has been detected, but not quantified in several different foods, such as anises, cocoa beans, fennels, and german camomiles. This could make p-anisic acid a potential biomarker for the consumption of these foods. It is a white crystalline solid which is insoluble in water, highly soluble in alcohols and soluble in ether, and ethyl acetate. p-Anisic acid has antiseptic properties. It is also used as an intermediate in the preparation of more complex organic compounds. It is generally obtained by the oxidation of anethole or p-methoxyacetophenone. The term "anisic acid" often refers to this form specifically. p-Anisic acid is found naturally in anise.
4-Hydroxycinnamic acid, also known as p-Coumaric acid, is a coumaric acid in which the hydroxy substituent is located at C-4 of the phenyl ring. It has a role as a plant metabolite. It is a conjugate acid of a 4-coumarate. p-coumaric acid is an organic compound that is a hydroxy derivative of cinnamic acid. There are three isomers of coumaric acid: o-coumaric acid, m-coumaric acid, and p-coumaric acid, that differ by the position of the hydroxy substitution of the phenyl group. p-Coumaric acid is the most abundant isomer of the three in nature. p-Coumaric acid exists in two forms trans-p-coumaric acid and cis-p-coumaric acid. It is a crystalline solid that is slightly soluble in water, but very soluble in ethanol and diethyl ether. 4-Hydroxycinnamic acid belongs to the class of organic compounds known as hydroxycinnamic acids. Hydroxycinnamic acids are compounds containing an cinnamic acid where the benzene ring is hydroxylated. 4-Hydroxycinnamic acid exists in all living species, ranging from bacteria to humans. Outside of the human body, 4-Hydroxycinnamic acid is found, on average, in the highest concentration within a few different foods, such as pepper (Capsicum frutescens), pineapples, and sunflowers and in a lower concentration in spinachs, kiwis, and sweet oranges. 4-Hydroxycinnamic acid has also been detected, but not quantified in several different foods, such as wild rices, soursops, garden onions, hyssops, and avocado.
In cosmetics, panthenol (also called pantothenol) is a humectant, emollient, and moisturizer. It binds to hair follicles readily and is a frequent component of shampoos and hair conditioners (in concentrations of 0.1-1%). It coats the hair and seals its surface, lubricating follicles and making strands appear shiny. Panthenol (specifically D-panthenol or dexpanthenol) is the alcohol analog of pantothenic acid (vitamin B5), and is thus the provitamin of B5. In organisms, it is quickly oxidized into pantothenate. Panthenol is a viscous transparent liquid at room temperature, but salts of pantothenic acid (for example sodium pantothenate) are powders (typically white). It is very soluble in water, alcohol, and propylene glycol, soluble in ether and chloroform, and only slightly soluble in glycerin.
Pantozol; Pantoprazole (brand names Pantopan in Italy; Protium; Protonix; Pantozol; Pantor; Pantoloc) is a proton pump inhibitor drug used for short-term treatment of erosion and ulceration of the esophagus caused by gastroesophageal reflux disease. Initial treatment is generally of eight weeks' duration, after which another eight week course of treatment may be considered if necessary. It can be used as a maintenance therapy for long term use after initial response is obtained; Pantoprazole is a proton pump inhibitor drug used for short-term treatment of erosion and ulceration of the esophagus caused by gastroesophageal reflux disease. Initial treatment is generally of eight weeks' duration, after which another eight week course of treatment may be considered if necessary. It can be used as a maintenance therapy for long term use after initial response is obtained. Pantoprazole is metabolized in the liver by the cytochrome P450 system. Metabolism mainly consists of demethylation by CYP2C19 followed by sulfation. Another metabolic pathway is oxidation by CYP3A4. Pantoprazole metabolites are not thought to have any pharmacological significance; Protium; Pantor; Pantoloc) is a proton pump inhibitor drug used for short-term treatment of erosion and ulceration of the esophagus caused by gastroesophageal reflux disease. Initial treatment is generally of eight weeks' duration, after which another eight week course of treatment may be considered if necessary. It can be used as a maintenance therapy for long term use after initial response is obtained; Protonix; Pantoprazole (brand names Pantopan in Italy.
Pantothenic acid, also called vitamin B5, is a water-soluble vitamin required to sustain life. Pantothenic acid is needed to form coenzyme-A (CoA), and is thus critical in the metabolism and synthesis of carbohydrates, proteins, and fats. Its name is derived from the Greek pantothen meaning "from everywhere" and small quantities of pantothenic acid are found in nearly every food, with high amounts in whole grain cereals, legumes, eggs, meat, and royal jelly. Pantothenic acid is classified as a member of the secondary alcohols. Secondary alcohols are compounds containing a secondary alcohol functional group, with the general structure HOC(R)(R') (R,R'=alkyl, aryl). Pantothenic acid is considered to be soluble (in water) and acidic.
Papaverine is an alkaloid found in opium but not closely related to the other opium alkaloids in its structure or pharmacological actions. It is a direct-acting smooth muscle relaxant used in the treatment of impotence and as a vasodilator, especially for cerebral vasodilation. The mechanism of its pharmacological actions is not clear, but it apparently can inhibit phosphodiesterases and it may have direct actions on calcium channels. [PubChem].
Paraoxon is an acetylcholinesterase inhibitor. It is an organophosphate oxon, and the active metabolite of the insecticide parathion. It is also used as an opthamological drug against glaucoma. Paraoxon is one of the most potent acetylcholinesterase-inhibiting insecticides available, around 70% as potent as the nerve agent sarin, and so is now rarely used as an insecticide due to the risk of poisoning to humans and other animals. It is easily absorbed through skin, and was used as an assassination weapon by the apartheid-era South African chemical weapons program Project Coast.
Pefloxacin is only found in individuals that have used or taken this drug. It is a synthetic broad-spectrum fluoroquinolone antibacterial agent active against most gram-negative and gram-positive bacteria. [PubChem]The bactericidal action of pefloxacin results from interference with the activity of the bacterial enzymes DNA gyrase and topoisomerase IV, which are needed for the transcription and replication of bacterial DNA. DNA gyrase appears to be the primary quinolone target for gram-negative bacteria. Topoisomerase IV appears to be the preferential target in gram-positive organisms. Interference with these two topoisomerases results in strand breakage of the bacterial chromosome, supercoiling, and resealing. As a result DNA replication and transcription is inhibited.
Penciclovir is only found in individuals that have used or taken this drug. It is a guanine analogue antiviral drug used for the treatment of various herpesvirus infections. It is a nucleoside analogue which exhibits low toxicity and good selectivity. [Wikipedia]Penciclovir has <i>in vitro</i> activity against herpes simplex virus types 1 (HSV-1) and 2 (HSV-2). In cells infected with HSV-1 or HSV-2, viral thymidine kinase phosphorylates penciclovir to a monophosphate form. The monophosphate form of the drug is then converted to penciclovir triphosphate by cellular kinases. The intracellular triphosphate of penciclovir is retained <i>in vitro</i> inside HSV-infected cells for 10-20 hours, compared with 0.7-1 hour for acyclovir. <i>in vitro</i> studies show that penciclovir triphosphate selectively inhibits viral DNA polymerase by competing with deoxyguanosine triphosphate. Inhibition of DNA synthesis of virus-infected cells inhibits viral replication. In cells not infected with HSV, DNA synthesis is unaltered. Resistant mutants of HSV can occur from qualitative changes in viral thymidine kinase or DNA polymerase. The most commonly encountered acyclovir-resistant mutants that are deficient in viral thymidine kinase are also resistant to penciclovir.
Pentazocine is only found in individuals that have used or taken this drug. It is the first mixed agonist-antagonist analgesic to be marketed. It is an agonist at the kappa and sigma opioid receptors and has a weak antagonist action at the mu receptor. (From AMA Drug Evaluations Annual, 1991, p97)The preponderance of evidence suggests that pentazocine antagonizes the opioid effects by competing for the same receptor sites, especially the opioid mu receptor.
Pentoxifylline is only found in individuals that have used or taken this drug. It is a methylxanthine derivative that inhibits phosphodiesterase and affects blood rheology. It improves blood flow by increasing erythrocyte and leukocyte flexibility. It also inhibits platelet aggregation. Pentoxifylline modulates immunologic activity by stimulating cytokine production. [PubChem]Pentoxifylline inhibits erythrocyte phosphodiesterase, resulting in an increase in erythrocyte cAMP activity. Subsequently, the erythrocyte membrane becomes more resistant to deformity. Along with erythrocyte activity, pentoxifylline also decreases blood viscosity by reducing plasma fibrinogen concentrations and increasing fibrinolytic activity. It is also a non selective adenosine receptor antagonist.
Pergolide is a long-acting dopamine agonist approved in 1982 for the treatment of Parkinson's Disease. It is an ergot derivative that acts on the dopamine D2 and D3, alpha2- and alpha1-adrenergic, and 5-hydroxytryptamine (5-HT) receptors. It was indicated as adjunct therapy with levodopa/carbidopa in the symptomatic treatment of parkinsonian syndrome. It was later found that pergolide increased the risk of cardiac valvulopathy. The drug was withdrawn from the US market in March 2007 and from the Canadian market in August 2007.
Petunidin 3-glucoside is found in alcoholic beverages. Petunidin 3-glucoside is present in red wine.
Phendimetrazine is a weight loss medication. Phendimetrazine is chemically related to amphetamines and is a Schedule III drug under the Convention on Psychotropic Substances. In the United States, phendimetrazine is a Schedule III controlled substance under the Uniform Controlled Substances Act of 1970.
Phenelzine is only found in individuals that have used or taken this drug. It is an irreversible non-selective inhibitor of monoamine oxidase. May be used to treat major depressive disorder.Although the exact mechanism of action has not been determined, it appears that the irreversible, nonselective inhibition of MAO by phenelzine relieves depressive symptoms by causing an increase in the levels of serotonin, norepinephrine, and dopamine in the neuron.
Phenmetrazine is only found in individuals that have used or taken this drug. It is a sympathomimetic drug used primarily as an appetite depressant. Its actions and mechanisms are similar to dextroamphetamine. [PubChem]Phenmetrazine is thought to block the reuptake of norepinephrine and dopamine into the presynaptic neuron leading to an increase in the release of these monoamines into the extraneuronal space. Dopamine integrates incoming sensory stimuli, initiates and controls fine movement (nigro-neostriatal pathway), controls emotional behavior (midbrain mesolimbic-forebrain system) and controls hypothalamic-pituitary endocrine system (tubero-infundibular system). It is this latter effect on the tubero-infundibular systm that seems to lead to reduced food intake. Phenmetrazine also acts as a monoamine oxidase inhibitor.
Phentermine is only found in individuals that have used or taken this drug. It is a central nervous system stimulant and sympathomimetic with actions and uses similar to those of dextroamphetamine. It has been used most frequently in the treatment of obesity. [PubChem]Phentermine is an amphetamine that stimulates neurons to release or maintain high levels of a particular group of neurotransmitters known as catecholamines; these include dopamine and norepinephrine. High levels of these catecholamines tend to suppress hunger signals and appetite. The drug seems to inhibit reuptake of noradrenaline, dopamine, and seratonin through inhibition or reversal of the reuptake transporters. It may also inhibit MAO enzymes leaving more neurotransmitter available at the synapse.Phentermine (through catecholamine elevation) may also indirectly affect leptin levels in the brain. It is theorized that phentermine can raise levels of leptin which signal satiety. It is also theorized that increased levels of the catecholamines are partially responsible for halting another chemical messenger known as neuropeptide Y. This peptide initiates eating, decreases energy expenditure, and increases fat storage.
Phenylacetaldehyde is one important oxidation-related aldehyde. Exposure to styrene gives phenylacetaldehyde as a secondary metabolite. Styrene has been implicated as reproductive toxicant, neurotoxicant, or carcinogen in vivo or in vitro. Phenylacetaldehyde could be formed by diverse thermal reactions during the cooking process together with C8 compounds is identified as a major aroma- active compound in cooked pine mushroom. Phenylacetaldehyde is readily oxidized to phenylacetic acid. Therefore will eventually be hydrolyzed and oxidized to yield phenylacetic acid that will be excreted primarily in the urine in conjugated form. (PMID: 16910727, 7818768, 15606130).
Phenylacetylglutamine is a product formed from the conjugation of phenylacetate and glutamine. Technically, it is the amino acid acetylation product of phenylacetate (or phenylbutyrate after beta-oxidation). Phenylacetylglutamine is a normal constituent of human urine, but other mammals such as the dog, cat, rat, monkey, sheep, and horse do not excrete this compound. Phenylacetyl-CoA and L-glutamine react to form phenylacetylglutamine and coenzyme A. The enzyme (glutamine N-acetyl transferase) that catalyzes this reaction has been purified from human liver mitochondria and shown to be a polypeptide species distinct from glycine-N-acyltransferase. Phenylacetylglutamine is a major nitrogenous metabolite that accumulates in uremia (PMID: 2791363, 8972626). It has been shown that over 50% of urine phenylacetylglutamine may be derived from kidney conjugation of free plasma phenylacetic acid and/or from the kidney's preferential filtration of conjugated phenylacetic acid (PMID: 6420430). Phenylacetylglutamine is a microbial metabolite found in Christensenellaceae, Lachnospiraceae and Ruminococcaceae (PMID: 26241311).
Phenylacetylglycine is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acyl glycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13) which is an enzyme that catalyzes the chemical reaction:. acyl-CoA + glycine < -- > CoA + N-acylglycine. Phenylacetylglycine or PAG is a glycine conjugate of phenylacetic acid. Phenylacetic acid may arise from exposure to styrene (plastic) or through the consumption of fruits and vegetables. Phenylacetic acid is used in some perfumes, possessing a honey-like odour in low concentrations, and is also used in penicillin G production. PAG is a putative biomarker of phospholipidosis. Urinary PAG is elevated in animals exhibiting abnormal phospholipid accumulation in many tissues and may thus be useful as a surrogate biomarker for phospholipidosis. (PMID: 15764292) The presence of phenylacetylglycine in urine has been confirmed for dogs, rats and mice. However, the presence of this compound in human urine is controversial. GC-MS studies have not found this compound (PMID: 7492634) while NMR studies claimed to have identified it (PMID: 21167146). It appears that phenylacetylglycine may sometimes be mistaken for phenylacetylglutamine via NMR.
2-Hydroxyphenethylamine, also known as beta-phenethanolamine or 2-amino-1-phenylethanol, belongs to the class of organic compounds known as aralkylamines. These are alkylamines in which the alkyl group is substituted at one carbon atom by an aromatic hydrocarbyl group. It is the simplest member of the class of phenylethanolamines that is 2-aminoethanol bearing a phenyl substituent at the 1-position. 2-Hydroxyphenethylamine exists in all living organisms, ranging from bacteria to humans. 2-Hydroxyphenethylamine ia an amine found in the brain. It may be modulator of sympathetic functions. Its derivatives are adrenergic agonists and antagonists.
Phloretin is the aglucone of phlorizin, a plant-derived dihydrochalcone phytochemical reported to promote potent antioxidative activities in peroxynitrite scavenging and the inhibition of lipid peroxidation. Phloretin, which is present in apples, pears and tomatoes, has been found to inhibit the growth of several cancer cells and induce apoptosis of B16 melanoma and HL60 human leukemia cells. Phloretin also inhibits HT-29 cell growth by inducing apoptosis, which may be mediated through changes in mitochondrial membrane permeability and activation of the caspase pathways. Phloretin is a well-known inhibitor of eukaryotic urea transporters, blocks VacA-mediated urea and ion transport (PMID:18158826, 11560962, 18063724, 15671209, 12083758). Phloretin is a biomarker for the consumption of apples. Phloretin has been found to be a metabolite of Escherichia (PMID:23542617).
Phloroglucinol is a benzenetriol. It is an organic compound that is used in the synthesis of pharmaceuticals and explosives. This molecule exists in two forms, or tautomers, 1,3,5-trihydroxybenzene, which has phenol-like, and 1,3,5-cyclohexanetrione (phloroglucin), which has ketone-like character. These two tautomers are in equilibrium. Phloroglucinol is a useful intermediate because it is polyfunctional. 1,3,5-Trihydroxybenzene has been found to be a metabolite in Pseudomonas (PMID: 15826166).
Phthalic acid is an aromatic dicarboxylic acid, with formula C6H4(COOH)2. Phthalic acid is used mainly in the form of the anhydride to produce other chemicals such as dyes, perfumes, saccharin, phthalates and many other useful products. Phthalic acid, when found in tissues or biofluids arises from exposure to these phthalate products. Phthalate is an environmental chemical of heightened public concern because reports of its potential risk to male reproductive health (PMID 16804814), being significantly associated with reduced sperm concentration to pesticide concentration in men's urine (PMID 16804812). Within the reproductive tract, the male is exquisitely vulnerable to the effects of anti-androgens during development due the reliance on the synthesis and action of androgens for the masculinization of the male reproductive tract. The ability of phthalates to suppress androgen synthesis during development and to induce testicular dysgenesis together with cryptorchidism and hypospadias has raised considerable concern. (PMID 15016950).
A cholinesterase inhibitor that is rapidly absorbed through membranes. It can be applied topically to the conjunctiva. It also can cross the blood-brain barrier and is used when central nervous system effects are desired, as in the treatment of severe anticholinergic toxicity. [PubChem]
Phytosphingosine is a phospholipid. Phospholipids are a class of lipids and a major component of all biological membranes; sphingolipid metabolites, such as sphingosine and ceramide, are highly bioactive compounds and are involved in diverse cell processes, including cell-cell interaction, cell proliferation, differentiation, and apoptosis. Phytosphingosine is also one of the most widely distributed natural sphingoid bases, which is abundant in fungi and plants, and also found in animals including humans. Phytosphingosine is structurally similar to sphingosine; phytosphingosine possesses a hydroxyl group at C-4 of the sphingoid long-chain base. The physiological roles of phytosphingosine are largely unknown. Phytosphingosine induces apoptosis in human T-cell lymphoma and non-small cell lung cancer cells, and induces caspase-independent cytochrome c release from mitochondria. In the presence of caspase inhibitors, phytosphingosine-induced apoptosis is almost completely suppressed, suggesting that phytosphingosine-induced apoptosis is largely dependent on caspase activities. (PMID: 12576463, 12531554, 8046331, 8048941,8706124).
Pilocarpine is only found in individuals that have used or taken this drug. It is a slowly hydrolyzed muscarinic agonist with no nicotinic effects. Pilocarpine is used as a miotic and in the treatment of glaucoma. [PubChem]Pilocarpine is a cholinergic parasympathomimetic agent. It increase secretion by the exocrine glands, and produces contraction of the iris sphincter muscle and ciliary muscle (when given topically to the eyes) by mainly stimulating muscarinic receptors.
Pioglitazone is used for the treatment of diabetes mellitus type 2. Pioglitazone selectively stimulates nuclear receptor peroxisone proliferator-activated receptor gamma (PPAR-gamma). It modulates the transcription of the insulin-sensitive genes involved in the control of glucose and lipid metabolism in the lipidic, muscular tissues and in the liver.
Pipecolic acid is a metabolite of lysine found in human physiological fluids such as urine, plasma and CSF. However, it is uncertain if pipecolic acid originates directly from food intake or from mammalian or intestinal bacterial enzyme metabolism. Recent studies suggest that plasma pipecolic acid, particularly the D-isomer, originates mainly from the catabolism of dietary lysine by intestinal bacteria rather than by direct food intake. In classic Zellweger syndrome (a cerebro-hepato-renal genetic disorder, OMIM 214100) pipecolic acid accumulate in the plasma of the patients. It is known that plasma pipecolic acid levels are also elevated in patients with chronic liver diseases. Pipecolic acid is moderately elevated in patients with pyridoxine-dependent seizures and might therefore be a possible biochemical marker for selecting candidates for pyridoxine therapy (Plecko et al 2000). Pipecolic acid was also elevated in CSF in these vitamin B6-responsive patients (PMID 12705501). Pipecolic acid is found to be associated with adrenoleukodystrophy, infantile Refsum disease, and peroxisomal biogenesis defect, which are also inborn errors of metabolism. Pipecolic acid is a biomarker for the consumption of dried and cooked beans.
Piperine, also known as fema 2909, belongs to the class of organic compounds known as alkaloids and derivatives. These are naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids. In addition to carbon, hydrogen and nitrogen, alkaloids may also contain oxygen, sulfur and more rarely other elements such as chlorine, bromine, and phosphorus. Piperine is a pepper tasting compound. Piperine is found in the highest concentration within pepper (Piper nigrum) and many other Piper species. Piperine has also been detected, but not quantified, in dills and herbs and spices.  Piperine is responsible for the hot taste of pepper. Piperine has been used in trials studying the treatment of Multiple Myeloma and Deglutition Disorders. It is used to impart pungent taste to brandy.
Piroxicam is only found in individuals that have used or taken this drug. It is a cyclooxygenase inhibiting, non-steroidal anti-inflammatory agent (NSAID) that is well established in treating rheumatoid arthritis and osteoarthritis and used for musculoskeletal disorders, dysmenorrhea, and postoperative pain. Its long half-life enables it to be administered once daily. [PubChem]The antiinflammatory effect of Piroxicam may result from the reversible inhibition of cyclooxygenase, causing the peripheral inhibition of prostaglandin synthesis. The prostaglandins are produced by an enzyme called Cox-1. Piroxicam blocks the Cox-1 enzyme, resulting into the disruption of production of prostaglandins. Piroxicam also inhibits the migration of leukocytes into sites of inflammation and prevents the formation of thromboxane A2, an aggregating agent, by the platelets.
Most statins are metabolised in part by one or more hepatic cytochrome P450 enzymes, leading to an increased potential for drug interactions and problems with certain foods (such as grapefruit juice). Pitavastatin appears to be a substrate of CYP2C9, and not CYP3A4 (which is a common source of interactions in other statins). As a result, pitavastatin is less likely to interact with drugs that are metabolized via CYP3A4, which might be important for elderly patients who need to take multiple medicines. Pitavastatin (usually as a calcium salt) is a member of the medication class of statins, marketed in the United States under the trade name Livalo. Like other statins, it is an inhibitor of HMG-CoA reductase, the enzyme that catalyses the first step of cholesterol synthesis. It has been available in Japan since 2003, and is being marketed under licence in South Korea and in India. It is likely that pitavastatin will be approved for use in hypercholesterolaemia (elevated levels of cholesterol in the blood) and for the prevention of cardiovascular disease outside South and Southeast Asia as well.
Porphobilinogen (PBG) is a pyrrole-containing intermediate in the biosynthesis of porphyrins. It is generated from aminolevulinate (ALA) by the enzyme ALA dehydratase. Porphobilinogen is then converted into hydroxymethylbilane by the enzyme porphobilinogen deaminase (also known as hydroxymethylbilane synthase). Under certain conditions, porphobilinogen can act as a phototoxin, a neurotoxin, and a metabotoxin. A phototoxin leads to cell damage upon exposure to light. A neurotoxin causes damage to nerve cells and nerve tissues. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Chronically high levels of porphyrins are associated with porphyrias such as porphyria variegate, acute intermittent porphyria, and hereditary coproporphyria (HCP). There are several types of porphyrias (most are inherited). Hepatic porphyrias are characterized by acute neurological attacks (seizures, psychosis, extreme back and abdominal pain, and an acute polyneuropathy), while the erythropoietic forms present with skin problems (usually a light-sensitive blistering rash and increased hair growth). The neurotoxicity of porphyrins may be due to their selective interactions with tubulin, which disrupt microtubule formation and cause neural malformations (PMID: 3441503).
Pramipexole is a medication indicated for treating Parkinson's disease and restless legs syndrome (RLS). It is also sometimes used off-label as a treatment for cluster headache or to counteract the problems with low libido experienced by some users of SSRI antidepressant drugs. Pramipexole has shown robust effects on pilot studies in bipolar disorder. Pramipexole is classified as a non-ergoline dopamine agonist.
Pravastatin is a member of the drug class of statins, used for lowering cholesterol and preventing cardiovascular disease. Pravastatin was identified originally in a mold called Nocardia autotrophica by researchers of the Sankyo Pharma Inc; An antilipemic fungal metabolite isolated from cultures of Nocardia autotrophica. It acts as a competitive inhibitor of HMG CoA reductase (hydroxymethylglutaryl CoA reductases); In medicine and pharmacology, pravastatin (Pravachol or Selektine) is a member of the drug class of statins, used for lowering cholesterol and preventing cardiovascular disease.
Prazepam is only found in individuals that have used or taken this drug. It is a benzodiazepine that is used in the treatment of anxiety disorders. It is a schedule IV drug in the U.S. Prazepam is believed to stimulate GABA receptors in the ascending reticular activating system. Since GABA is inhibitory, receptor stimulation increases inhibition and blocks both cortical and limbic arousal following stimulation of the brain stem reticular formation.
Prazosin is a selective &alpha;-<sub>1</sub>-adrenergic receptor antagonist used to treat hypertension. It has also been used to decrease urinary obstruction and relieve symptoms associated with symptomatic benign prostatic hyperplasia. &alpha;<sub>1</sub>-Receptors mediate contraction and hypertrophic growth of smooth muscle cells. Antagonism of these receptors leads to smooth muscle relaxation in the peripheral vasculature and prostate gland. Prazosin has also been used in conjunction with cardiac glycosides and diuretics in the management of severe congestive heart failure. It has also been used alone or in combination with &beta;-blockers in the preoperative management of signs and symptoms of pheochromocytoma.
Procarbazine is only found in individuals that have used or taken this drug. It is an antineoplastic agent used primarily in combination with mechlorethamine, vincristine, and prednisone (the MOPP protocol) in the treatment of Hodgkin's disease. [PubChem]The precise mode of cytotoxic action of procarbazine has not been clearly defined. There is evidence that the drug may act by inhibition of protein, RNA and DNA synthesis. Studies have suggested that procarbazine may inhibit transmethylation of methyl groups of methionine into t-RNA. The absence of functional t-RNA could cause the cessation of protein synthesis and consequently DNA and RNA synthesis. In addition, procarbazine may directly damage DNA. Hydrogen peroxide, formed during the auto-oxidation of the drug, may attack protein sulfhydryl groups contained in residual protein which is tightly bound to DNA.
Prochlorperazine is only found in individuals that have used or taken this drug. It is a phenothiazine antipsychotic used principally in the treatment of nausea; vomiting; and vertigo. It is more likely than chlorpromazine to cause extrapyramidal disorders. (From Martindale, The Extra Pharmacopoeia, 30th ed, p612)The mechanism of action of prochlorperazine has not been fully determined, but may be primarily related to its antidopaminergic effects. Prochlorperazine blocks the D2 somatodendritic autoreceptor, resulting in the blockade of postsynaptic dopamine receptors in the mesolimbic system and an increased dopamine turnover. Prochlorperazine also has anti-emetic effects, which can be attributed to dopamine blockade in the chemoreceptor trigger zone. Prochlorperazine also blocks anticholinergic and alpha-adrenergic receptors, the blockade of alpha(1)-adrenergic receptors resulting in sedation, muscle relaxation, and hypotension.
The major progestational steroid that is secreted primarily by the corpus luteum and the placenta. Progesterone acts on the uterus, the mammary glands and the brain. It is required in embryo implantation, pregnancy maintenance, and the development of mammary tissue for milk production. Progesterone, converted from pregnenolone, also serves as an intermediate in the biosynthesis of gonadal steroid hormones and adrenal corticosteroids. Progesterone is a C-21 steroid hormone involved in the female menstrual cycle, pregnancy (supports gestation) and embryogenesis of humans and other species. Progesterone belongs to a class of hormones called progestagens, and is the major naturally occurring human progestagen. During implantation and gestation, progesterone appears to decrease the maternal immune response to allow for the acceptance of the pregnancy. Progesterone decreases contractility of the uterine smooth muscle. The fetus metabolizes placental progesterone in the production of adrenal mineralo- and glucosteroids. A drop in progesterone levels is possibly one step that facilitates the onset of labor. In addition progesterone inhibits lactation during pregnancy. The fall in progesterone levels following delivery is one of the triggers for milk production. Progesterone is found to be associated with pregnene hydroxylation deficiency, which is an inborn error of metabolism.
Purine, also known as purine base or 1H-purine, belongs to the class of organic compounds known as purines and purine derivatives. These are aromatic heterocyclic compounds containing a purine moiety, which is formed a pyrimidine-ring ring fused to an imidazole ring. Two of the bases in nucleic acids, adenine and guanine, are purines. Purines from food (or from tissue turnover) are metabolised by several enzymes, including xanthine oxidase, into uric acid. Purine exists in all living species, ranging from bacteria to humans. High levels of uric acid can predispose to gout when the acid crystalises in joints; this phenomenon only happens in humans and some animal species (e.g. dogs) that lack an intrinsic uricase enzyme that can further degrade uric acid. In humans, purine is involved in thioguanine action pathway. Outside of the human body, purine is found, on average, in the highest concentration within cocoa beans. Purine has also been detected, but not quantified in several different foods, such as rapinis, plains prickly pears, blackcurrants, radish, and parsley. This could make purine a potential biomarker for the consumption of these foods. Purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring.
Pyridoxine, also known vitamin B6, is commonly found in food and is used as a dietary supplement. Pyridoxine is an essential nutrient, meaning the body cannot synthesize it, and it must be obtained from the diet. Sources in the diet include fruit, vegetables, and grain. Although pyridoxine and vitamin B6 are still frequently used as synonyms, especially by medical researchers, this practice is sometimes misleading (PMID: 2192605). Technically, pyridoxine is one of the compounds that can be called vitamin B6 or it is a member of the family of B6 vitamins. Healthy human blood levels of pyridoxine are 2.1 - 21.7 ng/mL. Pyridoxine is readily converted to pyridoxal phosphate which is a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids and aminolevulinic acid. Pyridoxine assists in the balancing of sodium and potassium as well as promoting red blood cell production. Therefore pyridoxine is required by the body to make amino acids, carbohydrates, and lipids. It is linked to cancer immunity and helps fight the formation of homocysteine. It has been suggested that pyridoxine might help children with learning difficulties, and may also prevent dandruff, eczema, and psoriasis. In addition, pyridoxine can help balance hormonal changes in women and aid in immune system. Lack of pyridoxine may cause anemia, nerve damage, seizures, skin problems, and sores in the mouth (Wikipedia). Deficiency of pyridoxine, though rare because of widespread distribution in foods, leads to the development of peripheral neuritis in adults and affects the central nervous system in children (DOSE - 3rd edition). As a supplement pyridoxine is used to treat and prevent pyridoxine deficiency, sideroblastic anaemia, pyridoxine-dependent epilepsy, certain metabolic disorders, problems from isoniazid, and certain types of mushroom poisoning. Pyridoxine in combination with doxylamine is used as a treatment for morning sickness in pregnant women.
Pyrrole-2-carboxylic acid was synthesized over a century ago, but its history as a compound of biological origin is rather recent. It was first identified as a degradation product of sialic acids, then as a derivative of the oxidation of the D-hydroxyproline isomers by mammalian D-amino acid oxidase. The latter relationship results from the lability of the direct oxidation product, A'-pyrroline-4-hydroxy-2-carboxylic acid, which loses water spontaneously to form the pyrrole. A similar reaction is catalyzed by the more specific allohydroxy-D-proline oxidase of Pseudomonas. In whole animal observations, pyrrole-2-carboxylate (PCA) ' was identified in rat or human urine after administration of the D-isomers of hydroxyproline, a finding ascribable to the action of D-amino acid oxidase. (PMID:4430715). Urinary excretion of N-(pyrrole-2-carboxyl) glycine has been reported in a 5-year-old affected with type II hyperprolinemia; The child has mild developmental delay, recurrent seizures of the grand mal type and EEG alterations. The urinary excretion of the conjugate is stressed, since it appears that only one previous report in the literature described this compound in the urine of two patients affected by this disturbance (PMID 2383933).
Quercetin 3-O-(6''-acetyl-glucoside) is a polyphenol compound found in foods of plant origin  (PMID: 20428313)
Quercitrin, also known as quercimelin or quercitronic acid, belongs to the class of organic compounds known as flavonoid-3-o-glycosides. These are phenolic compounds containing a flavonoid moiety which is O-glycosidically linked to carbohydrate moiety at the C3-position. A quercetin O-glycoside that is quercetin substituted by a alpha-L-rhamnosyl moiety at position 3 via a glycosidic linkage. Quercitrin exists in all living organisms, ranging from bacteria to humans. Quercitrin is found, on average, in the highest concentration within a few different foods, such as lingonberries, american cranberries, and olives and in a lower concentration in common beans, tea, and welsh onions. Quercitrin has also been detected, but not quantified, in several different foods, such as guava, bilberries, common pea, apricots, and spearmints.
Raffinose is a complex carbohydrate. It is a trisaccharide composed of galactose, fructose, and glucose. It can be found in beans, cabbage, brussels sprouts, broccoli, asparagus, other vegetables, and whole grains. Raffinose is hydrolyzed to D-galactose and sucrose by D-galactosidase (D-GAL). D-GAL also hydrolyzes other D-galactosides such as stachyose, verbascose, and galactinol [1-O-(D-galactosyl)-myoinositol], if present. The enzyme does not cleave linked galactose, as in lactose. Raffinose is also known as melitose and may be thought of as galactose and sucrose connected via an alpha(1->6) glycosidic linkage. Thus, raffinose can be broken down into galactose and sucrose via the enzyme alpha-galactosidase. Human intestines do not contain this enzyme. Raffinose is a trisaccharide occurring in Australian manna (from Eucalyptus spp, Myrtaceae) and in cottonseed meal.
Raltitrexed is only found in individuals that have used or taken this drug. It is a chemotherapy drug manufactured AstraZeneca Company, is an antimetabolite used in chemotherapy. It is an inhibitor of thymidylate synthase.Raltitrexed is an antineoplastic Agents and folic acid antagonists. Raltitrexed inhibits thymidylate synthase (TS) leading to DNA fragmentation and cell death. It is transported into cells via a reduced folate carrier. Inside the cell Raltitrexed is extensively polyglutamated, which enhances thymidylate synthase inhibitory power and duration. Inhibition of this enzyme results in decreased synthesis of thymidine triphosphate which is required for DNA synthesis.
Ramipril is a prodrug belonging to the angiotensin-converting enzyme (ACE) inhibitor class of medications. It is metabolized to ramiprilat in the liver and, to a lesser extent, kidneys. Ramiprilat is a potent, competitive inhibitor of ACE, the enzyme responsible for the conversion of angiotensin I (ATI) to angiotensin II (ATII). ATII regulates blood pressure and is a key component of the renin-angiotensin-aldosterone system (RAAS). Ramipril may be used in the treatment of hypertension, congestive heart failure, nephropathy, and to reduce the rate of death, myocardial infarction and stroke in individuals at high risk of cardiovascular events.
Ranitidine (CAS: 66357-35-5) is a non-imidazole blocker of histamine receptors that mediate gastric secretion (H2 receptors). It is used to treat gastrointestinal ulcers (PubChem). Ranitidine is a histamine H2-receptor antagonist that inhibits stomach acid production and is commonly used in the treatment of peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD). It is currently marketed by GlaxoSmithKline under the trade name Zantac (Wikipedia).
Ranolazine is only found in individuals that have used or taken this drug. It is an antianginal medication. On January 31, 2006, ranolazine was approved for use in the United States by the FDA for the treatment of chronic angina. [Wikipedia]The mechanism of action of ranolazine is unknown. It does not increase the rate-pressure product, a measure of myocardial work, at maximal exercise. In vitro studies suggest that ranolazine is a P-gp inhibitor. Ranolazine is believed to have its effects via altering the trans-cellular late sodium current. It is by altering the intracellular sodium level that ranolazine affects the sodium-dependent calcium channels during myocardial ischemia. Thus, ranolazine indirectly prevents the calcium overload that causes cardiac ischemia.
Repaglinide is an oral antihyperglycemic agent used for the treatment of non-insulin-dependent diabetes mellitus (NIDDM). It belongs to the meglitinide class of short-acting insulin secretagogues, which act by binding to cells of the pancreas to stimulate insulin release. Repaglinide induces an early insulin response to meals decreasing postprandial blood glucose levels. It should only be taken with meals and meal-time doses should be skipped with any skipped meal. Approximately one month of therapy is required before a decrease in fasting blood glucose is seen. Meglitnides may have a neutral effect on weight or cause a slight increase in weight. The average weight gain caused by meglitinides appears to be lower than that caused by sulfonylureas and insulin and appears to occur only in those naive to oral antidiabetic agents. Due to their mechanism of action, meglitinides may cause hypoglycemia although the risk is thought to be lower than that of sulfonylureas since their action is dependent on the presence of glucose. In addition to reducing postprandial and fasting blood glucose, meglitnides have been shown to decrease glycosylated hemoglobin (HbA1c) levels, which are reflective of the last 8-10 weeks of glucose control. Meglitinides appear to be more effective at lowering postprandial blood glucose than metformin, sulfonylureas and thiazolidinediones. Repaglinide is extensively metabolized in the liver and excreted in bile. Repaglinide metabolites do not possess appreciable hypoglycemic activity. Approximately 90% of a single orally administered dose is eliminated in feces and 8% in urine.
Resveratrol is a polyphenolic phytoalexin. It is also classified as a stilbenoid, a derivate of stilbene, and is produced in plants with the help of the enzyme stilbene synthase. The levels of resveratrol found in food vary greatly. Red wine contains between 0.2 and 5.8 mg/L depending on the grape variety, while white wine has much less. The reason for this difference is that red wine is fermented with grape skins, allowing the wine to absorb the resveratrol, whereas white wine is fermented after the skin has been removed. Resveratrol is also sold as a nutritional supplement. A number of beneficial health effects, such as anti-cancer, antiviral, neuroprotective, anti-aging, anti-inflammatory, and life-prolonging effects have been reported for resveratrol. The fact that resveratrol is found in the skin of red grapes and as a constituent of red wine may explain the "French paradox". This paradox is based on the observation that the incidence of coronary heart disease is relatively low in southern France despite high dietary intake of saturated fats. Resveratrol is thought to achieve these cardioprotective effects by a number of different routes: (1) inhibition of vascular cell adhesion molecule expression; (2) inhibition of vascular smooth muscle cell proliferation; (3) stimulation of endothelial nitric oxide synthase (eNOS) activity; (4) inhibition of platelet aggregation; and (5) inhibition of LDL peroxidation (PMID: 17875315, 14676260, 9678525). Resveratrol is a biomarker for the consumption of grapes and raisins.
all-trans-Retinoic acid is an isomer of retinoic acid, the oxidized form of vitamin A. Retinoic acid functions in determining position along embryonic anterior/posterior axis in chordates. It acts through Hox genes, which ultimately controls anterior/posterior patterning in early developmental stages (PMID:17495912). It is an important regulator of gene expression during growth and development, and in neoplasms. As a drug, all-trans-retinoic acid is known as tretinoin. Tretinoin is derived from maternal vitamin A and is essential for normal growth and embryonic development. An excess of tretinoin can be teratogenic. Tretinoin is used in the treatment of psoriasis, acne vulgaris, and several other skin diseases. It has also been approved for use in promyelocytic leukemia (leukemia, promyelocytic, acute).
Riboflavin or vitamin B2 is an easily absorbed, water-soluble micronutrient with a key role in maintaining human health. Like the other B vitamins, it supports energy production by aiding in the metabolizing of fats, carbohydrates, and proteins. Vitamin B2 is also required for red blood cell formation and respiration, antibody production, and for regulating human growth and reproduction. It is essential for healthy skin, nails, hair growth and general good health, including regulating thyroid activity. Riboflavin is found in milk, eggs, malted barley, liver, kidney, heart, and leafy vegetables. Riboflavin is yellow or orange-yellow in color and in addition to being used as a food coloring it is also used to fortify some foods. It can be found in baby foods, breakfast cereals, sauces, processed cheese, fruit drinks and vitamin-enriched milk products. The richest natural source is yeast. It occurs in the free form only in the retina of the eye, in whey, and in urine; its principal forms in tissues and cells are as flavin mononucleotide and flavin adenine dinucleotide.
Riluzole is only found in individuals that have used or taken this drug. It is a glutamate antagonist (receptors, glutamate) used as an anticonvulsant (anticonvulsants) and to prolong the survival of patients with amyotrophic lateral sclerosis. [PubChem]The mode of action of riluzole is unknown. Its pharmacological properties include the following, some of which may be related to its effect: 1) an inhibitory effect on glutamate release (activation of glutamate reuptake), 2) inactivation of voltage-dependent sodium channels, and 3) ability to interfere with intracellular events that follow transmitter binding at excitatory amino acid receptors.
Risperidone is an atypical antipsychotic medication approved in 1993. It is most often used to treat delusional psychosis (including schizophrenia), but risperidone (like other atypical antipsychotics) is also used to treat some forms of bipolar disorder, psychotic depression and Tourette syndrome. Generally lower doses are used for autistic spectrum disorders than are used for schizophrenia and other forms of psychosis; Risperidone is a very strong dopamine blocker (antagonist); Risperidone is a very strong dopamine blocker (antagonist); i.e., it inhibits functioning of postsynaptic dopamine receptors. An anxiolytic agent and a serotonin receptor agonist belonging to the azaspirodecanedione class of compounds. Its structure is unrelated to those of the benzodiazepines, but it has an efficacy comparable to diazepam; i.e., it inhibits functioning of postsynaptic dopamine receptors. Risperidone (Belivon, Rispen, Risperdal; in the United States) is an atypical antipsychotic medication. It was approved by the United States Food and Drug Administration (FDA) in 1993. It is most often used to treat delusional psychosis (including schizophrenia), but risperidone (like other atypical antipsychotics) is also used to treat some forms of bipolar disorder, psychotic depression and Tourette syndrome; risperidone has received approval from the Food and Drug Administration (FDA) for symptomatic treatment of irritability in autistic children and adolescents. Risperidone is now the most commonly prescribed antipsychotic medication in the United States.
Ritonavir is only found in individuals that have used or taken this drug. It is an HIV protease inhibitor that works by interfering with the reproductive cycle of HIV. [PubChem]Ritonavir inhibits the HIV viral proteinase enzyme which prevents cleavage of the gag-pol polyprotein, resulting in noninfectious, immature viral particles.
Rizatriptan is only found in individuals that have used or taken this drug. It is a triptan drug used for the treatment of migraine headaches. It is a selective 5-hydroxytryptamine1 receptor subtype agonist.Three distinct pharmacological actions have been implicated in the antimigraine effect of the triptans: (1) stimulation of presynaptic 5-HT1D receptors, which serves to inhibit both dural vasodilation and inflammation; (2) direct inhibition of trigeminal nuclei cell excitability via 5-HT1B/1D receptor agonism in the brainstem and (3) vasoconstriction of meningeal, dural, cerebral or pial vessels as a result of vascular 5-HT1B receptor agonism.
Rosiglitazone is an anti-diabetic drug from the thiazolidinedione class. Like other thiazolidinediones, its mechanism of action is by activation of the intracellular receptor class of the peroxisome proliferator-activated receptors (PPARs), specifically PPAR-gamma. Rosiglitazone is a pure ligand of PPAR-gamma, and has no PPAR-alpha-binding action. Apart from its effect on insulin resistance, it appears to have an anti-inflammatory effect: nuclear factor kappa-B (NF&#954;B) levels fall and inhibitor (I&#954;B) levels increase in patients on rosiglitazone (Mohanty et al). It increases glyceroneogenesis and reduces the release of free fatty acids from adipocytes; Rosiglitazone is an anti-diabetic drug from the thiazolidinedione class. It is being marketed as Avandia by the pharmaceutical company GlaxoSmithKline, both as a standalone preparation and in combination with metformin (Avandamet). Another combination drug approved by the FDA is Avandaryl (with glimepiride); Like other thiazolidinediones, its mechanism of action is by activation of the intracellular receptor class of the peroxisome proliferator-activated receptors (PPARs), specifically PPAR-gamma. Rosiglitazone is a pure ligand of PPAR-gamma, and has no PPAR-alpha binding action. Apart from its effect on insulin resistance, it appears to have an anti-inflammatory effect: nuclear factor kappa-B (NFkB) levels fall and inhibitor (IkB) levels increase in patients on rosiglitazone (Mohanty et al). It increases glyceroneogenesis and reduces the release of free fatty acids from adipocytes.
Roxatidine acetate is only found in individuals that have used or taken this drug. It is a specific and competitive H2 receptor antagonist. It is currently approved in South Africa under the tradename Roxit.The H2 antagonists are competitive inhibitors of histamine at the parietal cell H2 receptor. They suppress the normal secretion of acid by parietal cells and the meal-stimulated secretion of acid. They accomplish this by two mechanisms: histamine released by ECL cells in the stomach is blocked from binding on parietal cell H2 receptors which stimulate acid secretion, and other substances that promote acid secretion (such as gastrin and acetylcholine) have a reduced effect on parietal cells when the H2 receptors are blocked.
Rufloxacin belongs to the family of Phenylpiperazines. These are compounds containing a phenylpiperazine skeleton, which consists of a piperazine bound to a phenyl group.
Salicin, also known as salicoside or delta-salicin, is an aryl beta-D-glucoside that is salicyl alcohol in which the phenolic hydrogen has been replaced by a beta-D-glucosyl residue. It has a role as a prodrug, an antipyretic, a non-narcotic analgesic, a non-steroidal anti-inflammatory drug, an EC 1.14.99.1 (prostaglandin-endoperoxide synthase) inhibitor and a metabolite. It is an aryl beta-D-glucoside, an aromatic primary alcohol and a member of benzyl alcohols. It derives from a salicyl alcohol.  Salicin belongs to the class of organic compounds known as phenolic glycosides. These are organic compounds containing a phenolic structure attached to a glycosyl moiety. Some examples of phenolic structures include lignans, and flavonoids. Among the sugar units found in natural glycosides are D-glucose, L-Fructose, and L rhamnose. Salicin exists in all living organisms, ranging from bacteria to humans. Salicin is a bitter tasting compound.
Salmeterol is only found in individuals that have used or taken this drug. It is a long-acting beta2-adrenergic receptor agonist drug that is currently prescribed for the treatment of asthma and chronic obstructive pulmonary disease COPD. Salmeterol's long, lipophilic side chain binds to exosites near beta(2)-receptors in the lungs and on bronchiolar smooth muscle, allowing the active portion of the molecule to remain at the receptor site, continually binding and releasing. Beta(2)-receptor stimulation in the lung causes relaxation of bronchial smooth muscle, bronchodilation, and increased bronchial airflow.
Scopoletin is found in anise. Scopoletin is isolated from Angelica acutiloba (Dong Dang Gui
Symmetric dimethylarginine, also known as N,n'-dimethylarginine or SDMA, is a L-arginine derivative having two methyl groups at the N(omega)- and N'(omega)-positions It has a role as an EC 1.14.13.39 (nitric oxide synthase) inhibitor. It is a member of guanidines, a non-proteinogenic L-alpha-amino acid, a L-arginine derivative and a dimethylarginine. It is a tautomer of a N(omega),N'(omega)-dimethyl-L-arginine zwitterion. It belongs to the class of organic compounds known as arginine and derivatives. Arginine and derivatives are compounds containing arginine or a derivative thereof resulting from reaction of arginine at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom. Symmetric dimethylarginine is a drug. Outside of the human body, symmetric dimethylarginine has been detected, but not quantified in pulses. Symmetric dimethylarginine (SDMA) is an endogenously produced inhibitor of nitric oxide synthase (EC-Number 1.14.13.39). However, elevated levels of Symmetric dimethylarginine occur in patients with vascular disease, especially suffering end-stage renal disease.
Sibutramine (trade name Meridia in the USA, Reductil in Europe and other countries), usually as sibutramide hydrochloride monohydrate, is an orally administered agent for the treatment of obesity. It is a centrally acting stimulant chemically related to amphetamines. Sibutramine is classified as a Schedule IV controlled substance in the United States. In October 2010, Sibutramine was withdrawn from Canadian and U.S. markets due to concerns that the drug increases the risk of heart attack and stroke in patients with a history of heart disease.
Sotalol is only found in individuals that have used or taken this drug. It is an adrenergic beta-antagonist that is used in the treatment of life-threatening arrhythmias (PubChem). Sotalol has both beta-adrenoreceptor blocking (Vaughan Williams Class I) and cardiac action potential duration prolongation (Vaughan Williams Class I) antiarrhythmic properties. Sotalol is a racemic mixture of d- and l-sotalol. Both isomers have similar Class I antiarrhythmic effects, while the l-isomer is responsible for virtually all of the beta-blocking activity. Sotalol inhibits response to adrenergic stimuli by competitively blocking &#946;<sub>1</sub>-adrenergic receptors within the myocardium and &#946;<sub>2</sub>-adrenergic receptors within bronchial and vascular smooth muscle. The electrophysiologic effects of sotalol may be due to its selective inhibition of the rapidly activating component of the potassium channel involved in the repolarization of cardiac cells. The class II electrophysiologic effects are caused by an increase in sinus cycle length (slowed heart rate), decreased AV nodal conduction, and increased AV nodal refractoriness, while the class III electrophysiological effects include prolongation of the atrial and ventricular monophasic action potentials, and effective refractory period prolongation of atrial muscle, ventricular muscle, and atrio-ventricular accessory pathways (where present) in both the anterograde and retrograde directions.
Stavudine is only found in individuals that have used or taken this drug. It is a dideoxynucleoside analog that inhibits reverse transcriptase and has in vitro activity against HIV. [PubChem]Stavudine inhibits the activity of HIV-1 reverse transcriptase (RT) both by competing with the natural substrate dGTP and by its incorporation into viral DNA.
Sucrose is a nonreducing disaccharide composed of glucose and fructose linked via their anomeric carbons. It is obtained commercially from sugarcane (Saccharum officinarum), sugar beet (Beta vulgaris), and other plants and used extensively as a food and a sweetener. Sucrose is derived by crushing and extracting sugarcane with water or by extracting sugar beet with water, evaporating, and purifying with lime, carbon, and various liquids. Sucrose is also obtainable from sorghum. Sucrose occurs in low percentages in honey and maple syrup. Sucrose is used as a sweetener in foods and soft drinks, in the manufacture of syrups, in invert sugar, confectionery, preserves and jams, demulcent, pharmaceutical products, and caramel. Sucrose is also a chemical intermediate for detergents, emulsifying agents, and other sucrose derivatives. Sucrose is widespread in the seeds, leaves, fruits, flowers, and roots of plants, where it functions as an energy store for metabolism and as a carbon source for biosynthesis. The annual world production of sucrose is in excess of 90 million tons mainly from the juice of sugar cane (20%) and sugar beet (17%). In addition to its use as a sweetener, sucrose is used in food products as a preservative, antioxidant, moisture control agent, stabilizer, and thickening agent. BioTransformer predicts that sucrose is a product of 6-O-sinapoyl sucrose metabolism via a hydrolysis-of-carboxylic-acid-ester-pattern1 reaction occurring in human gut microbiota and catalyzed by the liver carboxylesterase 1 (P23141) enzyme (PMID: 30612223).
Sulforaphane (SFN) is the most characterized isothiocyanate. SFN has received a great deal of attention because of its ability to simultaneously modulate multiple cellular targets involved in cancer development, including: (i) DNA protection by modulating carcinogen-metabolizing enzymes and blocking the action of mutagens; (ii) inhibition of cell proliferation and induction of apoptosis, thereby retarding or eliminating clonal expansion of initiated, transformed, and/or neoplastic cells; (iii) inhibition of neoangiogenesis, progression of benign tumors to malignant tumors, and metastasis formation. SFN is therefore able to prevent, delay, or reverse preneoplastic lesions, as well as to act on cancer cells as a therapeutic agent. Taking into account this evidence and its favorable toxicological profile, SFN can be viewed as a conceptually promising agent in cancer prevention and/or therapy. SFN is the hydrolysis product of glucoraphanin, particularly high in the young sprouts of broccoli and cauliflower. SFN can also be obtained by eating cruciferous vegetables such as brussel sprouts, broccoli, cauliflower, bok choy, kale, collards, arugula, broccoli sprouts, chinese broccoli, broccoli raab, kohlrabi, mustard, turnip, radish, watercress and cabbage (PMID:17134937).
Oftentimes, serotonin levels in the brain become extremely erratic before the onset of a migraine. In an attempt to stabilize this, sumatriptan is administered to help aid in leveling the serotonin levels in the brain. Sumatriptan is structurally similar to serotonin, and is a 5-HT (5-HT1D) agonist, which is one of the receptors that serotonin binds to. The specific receptor subtype it activates is present in the cranial and basilar arteries. Activation of these receptors causes vasoconstriction of those dilated arteries. Sumatriptan is also shown to decrease the activity of the trigeminal nerve. Sumatriptan is a triptan drug including a sulfonamide group structurally similar to serotonin, and is a 5-HT (5-HT1D) agonist, which is one of the receptors that serotonin binds to. Oftentimes, serotonin levels in the brain become extremely erratic before the onset of a migraine. In an attempt to stabilize this, sumatriptan is administered to help aid in leveling the serotonin levels in the brain. A serotonin agonist that acts selectively at 5HT1 receptors. It is used in the treatment of migraines. Sumatriptan (Imitrex, Imigran, Imigran Recovery) is a triptan drug including a sulfonamide group which was originally developed by Glaxo for the treatment of migraine headaches.
p-Synephrine is an endogenous amine in plasma, in variable levels with a tendency to be higher in hypertensive patients (PMID 8255371).
Syringic acid, also known as syringate or cedar acid, belongs to the class of organic compounds known as gallic acid and derivatives. Gallic acid and derivatives are compounds containing a 3,4,5-trihydroxybenzoic acid moiety. Outside of the human body, Syringic acid is found, on average, in the highest concentration within a few different foods, such as common walnuts, swiss chards, and olives and in a lower concentration in apples, tarragons, and peanuts. Syringic acid has also been detected, but not quantified in several different foods, such as sweet marjorams, silver lindens, bulgurs, annual wild rices, and barley. This could make syringic acid a potential biomarker for the consumption of these foods. Syringic acid is correlated with high antioxidant activity and inhibition of LDL oxidation. Research suggests that phenolics from wine may play a positive role against oxidation of low-density lipoprotein (LDL), which is a key step in the development of atherosclerosis. Syringic acid is a phenol present in some distilled alcohol beverages. It is also a product of microbial (gut) metabolism of anthocyanins and other polyphenols that have been consumed (in fruits and alcoholic beverages - PMID:18767860). Syringic acid is also a microbial metabolite that can be found in Bifidobacterium (PMID:24958563).
Tacrine is only found in individuals that have used or taken this drug. It is a centerally active cholinesterase inhibitor that has been used to counter the effects of muscle relaxants, as a respiratory stimulant, and in the treatment of Alzheimer's disease and other central nervous system disorders. [PubChem]The mechanism of tacrine is not fully known, but it is suggested that the drug is an anticholinesterase agent which reversibly binds with and inactivates cholinesterases. This inhibits the hydrolysis of acetylcholine released from functioning cholinergic neurons, thus leading to an accumulation of acetylcholine at cholinergic synapses. The result is a prolonged effect of acetylcholine.
Tacrolimus (also FK-506 or Fujimycin) is an immunosuppressive drug whose main use is after organ transplant to reduce the activity of the patient's immune system and so the risk of organ rejection. It is also used in a topical preparation in the treatment of severe atopic dermatitis, severe refractory uveitis after bone marrow transplants, and the skin condition vitiligo. It was discovered in 1984 from the fermentation broth of a Japanese soil sample that contained the bacteria Streptomyces tsukubaensis. Tacrolimus is chemically known as a macrolide. It reduces peptidyl-prolyl isomerase activity by binding to the immunophilin FKBP-12 (FK506 binding protein) creating a new complex. This FKBP12-FK506 complex interacts with and inhibits calcineurin thus inhibiting both T-lymphocyte signal transduction and IL-2 transcription.
Tadalafil is an orally adminstered drug used to treat male erectile dysfunction (impotence). It is marketed worldwide under the brand name Cialis. It is a phosphodiesterase 5 (PDE5) inhibitor. Tadalafil's distinguishing pharmacologic feature is its longer half-life (17.5 hours) compared with Viagra and Levitra (4-5 hours). This longer half-life results in a longer duration of action and is, in part, responsible for the Cialis nickname of the 'weekend pill.' This longer half-life also is the basis of current investigation for tadalafil's use in pulmonary arterial hypertension as a once-daily therapy. [Wikipedia]
L-Targinine is found in pulses. L-Targinine is isolated from broad bean seed L-Targinine has been identified in the human placenta (PMID: 32033212).
Taurocholic acid is a bile acid and is the product of the conjugation of cholic acid with taurine. Its sodium salt is the chief ingredient of the bile of carnivorous animals. Bile acids are steroid acids found predominantly in the bile of mammals. The distinction between different bile acids is minute, depending only on the presence or absence of hydroxyl groups on positions 3, 7, and 12. Bile acids are physiological detergents that facilitate excretion, absorption, and transport of fats and sterols in the intestine and liver. Bile acids are also steroidal amphipathic molecules derived from the catabolism of cholesterol. They modulate bile flow and lipid secretion, are essential for the absorption of dietary fats and vitamins, and have been implicated in the regulation of all the key enzymes involved in cholesterol homeostasis. Bile acids recirculate through the liver, bile ducts, small intestine, and portal vein to form an enterohepatic circuit. They exist as anions at physiological pH, and consequently require a carrier for transport across the membranes of the enterohepatic tissues. The unique detergent properties of bile acids are essential for the digestion and intestinal absorption of hydrophobic nutrients. Bile acids have potent toxic properties (e.g. membrane disruption) and there are a plethora of mechanisms to limit their accumulation in blood and tissues (PMID: 11316487, 16037564, 12576301, 11907135). Taurocholic acid, as with all bile acids, acts as a detergent to solubilize fats for absorption and is itself absorbed. It is used as a cholagogue and choleretic (a bile purging agent). Hydrolysis of taurocholic acid yields taurine, a nonessential amino acid. Taurocholic acid is one of the main components of urinary nonsulfated bile acids in biliary atresia. Raised levels of taurocholate in fetal serum in obstetric cholestasis may result in the development of a fetal dysrhythmia and sudden intra-uterine death (PMID: 3944741, 11256973).
Telmisartan is an angiotensin II receptor antagonist (ARB) used in the management of hypertension. Generally, angiotensin II receptor blockers (ARBs) such as telmisartan bind to the angiotensin II type 1 (AT1) receptors with high affinity, causing inhibition of the action of angiotensin II on vascular smooth muscle, ultimately leading to a reduction in arterial blood pressure. Recent studies suggest that telmisartan may also have PPAR-gamma agonistic properties that could potentially confer beneficial metabolic effects.
Temazepam is only found in individuals that have used or taken this drug. It is a benzodiazepine that acts as a gamma-aminobutyric acid modulator and anti-anxiety agent. [PubChem]Benzodiazepines bind nonspecifically to benzodiazepine receptors, which affects muscle relaxation, anticonvulsant activity, motor coordination, and memory. As benzodiazepine receptors are thought to be coupled to gamma-aminobutyric acid-A (GABA<sub>A</sub>) receptors, this enhances the effects of GABA by increasing GABA affinity for the GABA receptor. Binding of the inhibitory neurotransmitter GABA to the site opens the chloride channel, resulting in a hyperpolarized cell membrane that prevents further excitation of the cell.
Temozolomide (Temodar and Temodal) is an oral alkylating agent used for the treatment of refractory anaplastic astrocytoma -- a type of cancerous brain tumor. Temozolomide is not active until it is converted at physiologic pH to the active form, 5-(3-methyltriazen-1-yl)imidazole-4-carboxamide (MTIC).
Terazosin is a selective alpha1-antagonist used for treatment of symptoms of benign prostatic hyperplasia (BPH). It also acts to lower blood pressure, so it is a drug of choice for men with hypertension and prostate enlargement. It works by blocking the action of adrenaline on smooth muscle of the bladder and the blood vessel walls.
Terbinafine hydrochloride (Lamisil) is a synthetic allylamine antifungal. It is highly lipophilic in nature and tends to accumulate in skin, nails, and fatty tissues. Like other allylamines, terbinafine inhibits ergosterol synthesis by inhibiting the fungal squalene monooxygenase (squalene 2,3-epoxidase), an enzyme that is part of the fungal cell wall synthesis pathway.
L-Theanine, also known as L-gamma-glutamylethylamide or N-gamma-ethyl-L-glutamine, is a member of the class of compounds known as glutamine and derivatives. These compounds contain glutamine or a derivative thereof resulting from a reaction of glutamine at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom. L-Theanine is slightly soluble (in water) and a moderately acidic compound (based on its pKa). L-Theanine can be found in saliva. The regulatory status of theanine varies by country. In Japan, L-theanine has been approved for use in all foods, including herb teas, soft drinks, and desserts. Restrictions apply to infant foods. In the United States, the Food and Drug Administration (FDA) considers it to be generally recognized as safe (GRAS) and allows its sale as a dietary supplement. The German Federal Institute for Risk Assessment, an agency of their Federal Ministry of Food and Agriculture, objects to the addition of L-theanine to beverages. The European Food Safety Authority EFSA advised negatively on health claims related to L-theanine and cognitive function, alleviation of psychological stress, maintenance of normal sleep, and reduction of menstrual discomfort. Therefore, health claims for L-theanine are prohibited in the European Union (Wikipedia). L-Theanine is found in mushrooms and is a constituent of tea (Thea sinensis) and of the fungus Imleria badia. L-Theanine has been shown to exhibit neuroprotectant and neuroprotective functions (PMID: 20416364, 20416364).
Theophylline, also known as quibron TSR or uniphyl, belongs to the class of organic compounds known as xanthines. These are purine derivatives with a ketone group conjugated at carbons 2 and 6 of the purine moiety. Theophylline also binds to the adenosine A2B receptor and blocks adenosine mediated bronchoconstriction. Theophylline is a drug which is used for the treatment of the symptoms and reversible airflow obstruction associated with chronic asthma and other chronic lung diseases, such as emphysema and chronic bronchitis. Theophylline is marketed under several brand names such as Theophylline and Theochron, and it is indicated mainly for asthma, bronchospasm, and COPD. Within humans, theophylline participates in a number of enzymatic reactions. In particular, theophylline and formaldehyde can be biosynthesized from caffeine; which is mediated by the enzymes cytochrome P450 1A2, cytochrome P450 3A4, cytochrome P450 2C8, cytochrome P450 2C9, and cytochrome P450 2E1. In addition, theophylline can be converted into 1-methylxanthine and formaldehyde; which is mediated by the enzyme cytochrome P450 1A2. In humans, theophylline is involved in caffeine metabolism. Theophylline is a bitter tasting compound. Outside of the human body, Theophylline is found, on average, in the highest concentration within cocoa beans and tea. Theophylline has also been detected, but not quantified in a few different foods, such as arabica coffee, lemons, and pummelo. This could make theophylline a potential biomarker for the consumption of these foods. Theophylline is a potentially toxic compound.
Thymidine, also known as deoxythymidine or deoxyribosylthymine or thymine deoxyriboside, is a pyrimidine deoxynucleoside. It consists of the nucleobase thymine attached to deoxyribose through a beta N- glycosidic bond. Thymidine also belongs to the class of organic compounds known as pyrimidine 2'-deoxyribonucleosides. Pyrimidine 2'-deoxyribonucleosides are compounds consisting of a pyrimidine linked to a ribose which lacks a hydroxyl group at position 2. Deoxythymidine (or thymidine) is the DNA nucleoside T, which pairs with deoxyadenosine (A) in double-stranded DNA. Therefore, thymidine is essential to all life. Indeed, thymidine exists in all living species, ranging from bacteria to plants to humans. Within humans, thymidine participates in a number of enzymatic reactions. In particular, thymidine can be biosynthesized from 5-thymidylic acid through its interaction with the enzyme cytosolic purine 5'-nucleotidase. In addition, thymidine can be converted into 5-thymidylic acid; which is catalyzed by the enzyme thymidine kinase. Deoxythymidine can be phosphorylated with one, two or three phosphoric acid groups, creating dTMP (deoxythymidine monophosphate), dTDP, or dTTP (for the di- and tri- phosphates, respectively). dTMP can be incorporated into DNA via DNA polymerases. In cell biology, thymidine can be used to synchronize the cells in S phase. Derivatives of thymidine are used in a number of drugs, including Azidothymidine (AZT), which is used in the treatment of HIV infection. AZT inhibits the process of reverse transcription in the human immunodeficiency virus.
Tiagabine is an anti-convulsive medication. It is also used in the treatment for panic disorder as are a few other anticonvulsants. Though the exact mechanism by which tiagabine exerts its effect on the human body is unknown, it does appear to operate as a selective GABA reuptake inhibitor.
Ticlopidine is an effective inhibitor of platelet aggregation. The drug has been found to significantly reduce infarction size in acute myocardial infarcts and is an effective antithrombotic agent in arteriovenous fistulas, aorto-coronary bypass grafts, ischemic heart disease, venous thrombosis, and arteriosclerosis. [PubChem]
Tinidazole is only found in individuals that have used or taken this drug. It is a nitroimidazole antitrichomonal agent effective against Trichomonas vaginalis, Entamoeba histolytica, and Giardia lamblia infections. [PubChem]Tinidazole is a prodrug and antiprotozoal agent. The nitro group of tinidazole is reduced in <i>Trichomonas</i> by a ferredoxin-mediated electron transport system. The free nitro radical generated as a result of this reduction is believed to be responsible for the antiprotozoal activity. It is suggested that the toxic free radicals covalently bind to DNA, causing DNA damage and leading to cell death. The mechanism by which tinidazole exhibits activity against <i>Giardia</i> and <i>Entamoeba</i> species is not known, though it is probably similar.
Tocainide is only found in individuals that have used or taken this drug. It is an antiarrhythmic agent which exerts a potential- and frequency-dependent block of sodium channels. [PubChem]Tocainide acts on sodium channels on the neuronal cell membrane, limiting the spread of seizure activity and reducing seizure propagation. Tocainide binds preferentially to the inactive state of the sodium channels.The antiarrhythmic actions are mediated through effects on sodium channels in Purkinje fibers.
Tolterodine is only found in individuals that have used or taken this drug. It is an antimuscarinic drug that is used to treat urinary incontinence. Tolterodine acts on M2 and M3 subtypes of muscarinic receptors.Both tolterodine and its active metabolite, 5-hydroxymethyltolterodine, act as competitive antagonists at muscarinic receptors. This antagonism results in inhibition of bladder contraction, decrease in detrusor pressure, and an incomplete emptying of the bladder.
Topotecan is only found in individuals that have used or taken this drug. It is an antineoplastic agent used to treat ovarian cancer. It works by inhibiting DNA topoisomerases, type I. [PubChem]Topotecan has the same mechanism of action as irinotecan and is believed to exert its cytotoxic effects during the S-phase of DNA synthesis. Topoisomerase I relieves torsional strain in DNA by inducing reversible single strand breaks. Topotecan binds to the topoisomerase I-DNA complex and prevents religation of these single strand breaks. This ternary complex interferes with the moving replication fork, which leads to the induction of replication arrest and lethal double-stranded breaks in DNA. As mammalian cells cannot efficiently repair these double strand breaks, the formation of this ternary complex eventually leads to apoptosis (programmed cell death).Topotecan mimics a DNA base pair and binds at the site of DNA cleavage by intercalating between the upstream (âˆ’1) and downstream (+1) base pairs. Intercalation displaces the downstream DNA, thus preventing religation of the cleaved strand. By specifically binding to the enzymeâ€“substrate complex, Topotecan acts as an uncompetitive inhibitor.
Ketorolac is only found in individuals that have used or taken this drug. It is a pyrrolizine carboxylic acid derivative structurally related to indomethacin. It is an NSAID and is used principally for its analgesic activity (from Martindale The Extra Pharmacopoeia, 31st ed). Ketorolac is a nonsteroidal anti-inflammatory drug (NSAID) chemically related to indomethacin and tolmetin. Ketorolac tromethamine is a racemic mixture of [-]S- and [+]R-enantiomeric forms, with the S-form having analgesic activity. Its antiinflammatory effects are believed to be due to inhibition of both cylooxygenase-1 (COX-1) and cylooxygenase-2 (COX-2) which leads to the inhibition of prostaglandin synthesis leading to decreased formation of precursors of prostaglandins and thromboxanes from arachidonic acid. The resultant reduction in prostaglandin synthesis and activity may be at least partially responsible for many of the adverse, as well as the therapeutic, effects of these medications. Analgesia is probably produced via a peripheral action in which blockade of pain impulse generation results from decreased prostaglandin activity. However, inhibition of the synthesis or actions of other substances that sensitize pain receptors to mechanical or chemical stimulation may also contribute to the analgesic effect. In terms of the ophthalmic applications of ketorolac - ocular administration of ketorolac reduces prostaglandin E2 levels in aqueous humor, secondary to inhibition of prostaglandin biosynthesis.
Torasemide (rINN) or torsemide (USAN) is a pyridine-sulfonylurea type loop diuretic mainly used in the management of edema associated with congestive heart failure. It is also used at low doses for the management of hypertension. It is marketed under the brand name Demadex. [Wikipedia]
Tramadol is only found in individuals that have used or taken this drug. It is a narcotic analgesic proposed for moderate to severe pain. It may be habituating (PubChem). Tramadol and its O-desmethyl metabolite (M1) are selective, weak OP3-receptor agonists. Opiate receptors are coupled with G-protein receptors and function as both positive and negative regulators of synaptic transmission via G-proteins that activate effector proteins. As the effector system is adenylate cyclase and cAMP is located at the inner surface of the plasma membrane, opioids decrease intracellular cAMP by inhibiting adenylate cyclase. Subsequently, the release of nociceptive neurotransmitters such as substance P, GABA, dopamine, acetylcholine, and noradrenaline is inhibited. The analgesic properties of tramadol can be attributed to norepinephrine and serotonin reuptake blockade in the CNS, which inhibits pain transmission in the spinal cord. The (+) enantiomer has a higher affinity for the OP3 receptor and preferentially inhibits serotonin uptake and enhances serotonin release. The (-) enantiomer preferentially inhibits norepinephrine reuptake by stimulating alpha(2)-adrenergic receptors.
trans-Piceid is found in alcoholic beverages. trans-Piceid is present in grapeskins and red wine. It is isolated from Polygonum cuspidatum (Japanese knotweed).Piceid is a stilbenoid glucoside and is a major resveratrol derivative in grape juices
A serotonin uptake inhibitor that is used as an antidepressive agent. It has been shown to be effective in patients with major depressive disorders and other subsets of depressive disorders. It is generally more useful in depressive disorders associated with insomnia and anxiety. This drug does not aggravate psychotic symptoms in patients with schizophrenia or schizoaffective disorders. (From AMA Drug Evaluations Annual, 1994, p309)
Trehalose 6-phosphate is a substrate for Hexokinase (type I) and Tryptase beta-1. Trehalose 6-phosphate has been found to be a microbial metabolite in Escherichia, Mycobacterium and Saccharomyces (UniProt).
Triazolam is only found in individuals that have used or taken this drug.It is withdrawn in the United Kingdom due to risk of psychiatric adverse drug reactions. This drug continues to be available in the U.S. Internationally, triazolam is a Schedule IV drug under the Convention on Psychotropic Substances.Benzodiazepines bind nonspecifically to bezodiazepine receptors BNZ1, which mediates sleep, and BNZ2, which affects affects muscle relaxation, anticonvulsant activity, motor coordination, and memory. As benzodiazepine receptors are thought to be coupled to gamma-aminobutyric acid-A (GABA<sub>A</sub>) receptors, this enhances the effects of GABA by increasing GABA affinity for the GABA receptor. Binding of GABA to the site opens the chloride channel, resulting in a hyperpolarized cell membrane that prevents further excitation of the cell.
Trifluoperazine is only found in individuals that have used or taken this drug. It is a phenothiazine with actions similar to chlorpromazine. It is used as an antipsychotic and an antiemetic. [PubChem]Trifluoperazine blocks postsynaptic mesolimbic dopaminergic D1 and D2 receptors in the brain; depresses the release of hypothalamic and hypophyseal hormones and is believed to depress the reticular activating system thus affecting basal metabolism, body temperature, wakefulness, vasomotor tone, and emesis.
Oxcarbazepine is structurally a derivative of carbamazepine, adding an extra oxygen atom to the benzylcarboxamide group. This difference helps reduce the impact on the liver of metabolizing the drug, and also prevents the serious forms of anemia occasionally associated with carbamazepine. Aside from this reduction in side effects, it is thought to have the same mechanism as carbamazepine - sodium channel inhibition - and is generally used to treat partial seizures in epileptic children and adults.
Trimipramine is only found in individuals that have used or taken this drug. It is a tricyclic antidepressant similar to imipramine, but with more antihistaminic and sedative properties. [PubChem]Trimipramine's mechanism of action differs from other tricyclic antidepressants. Trimipramine acts by decreasing the reuptake of norepinephrine and serotonin (5-HT).
Tripelennamine is only found in individuals that have used or taken this drug. It is a histamine H1 antagonist with low sedative action but frequent gastrointestinal irritation. It is used to treat asthma; HAY fever; urticaria; and rhinitis; and also in veterinary applications. Tripelennamine is administered by various routes, including topically. [PubChem]Tripelennamine binds to the histamine H1 receptor. This blocks the action of endogenous histamine, which subsequently leads to temporary relief of the negative symptoms brought on by histamine.
Tryptamine, also known as TrpN, is a catabolite of tryptophan converted by the gut microbiota. After absorption through the intestinal epithelium, tryptophan catabolites enter the bloodstream and are later excreted in the urine. Both Clostridium sp. and Ruminococcus sp. have been found to convert tryptophan into tryptamine (PMID: 30120222). Tryptamine is a monoamine compound that is a common precursor molecule to many hormones and neurotransmitters. Biosynthesis generally proceeds from the amino acid tryptophan, with tryptamine acting as a precursor for other compounds. Substitutions to the tryptamine molecule give rise to a group of compounds collectively known as tryptamines. The most well-known tryptamines are serotonin, an important neurotransmitter, and melatonin, a hormone involved in regulating the sleep-wake cycle. Tryptamine has been detected, but not quantified in, several different foods, such as onion-family vegetables, acerola, Japanese walnuts, custard apples, and green zucchinis. This could make tryptamine a potential biomarker for the consumption of these foods.
Tetrahydro-b-carbolines (THbCs)are potential neuroactive alkaloids found in chocolate and cocoa. The formation of 1,2,3,4-tetrahydro-/3-carbolines (THBCs), via the Pictet-Spengler condensation of tryptamines with formaldehyde, has been demonstrated repeatedly in incubations of various mammalian tissues containing added indolethylamine substrate and the methyl donors .5-methyltetrahydrofolate (5-MTHF) or S-adenosylmethionine(SAM). It is concluded that the formation of these THBCs is an artifact produced by the enzymatic liberation of formaldehyde from the methyl donors and the subsequent non-enzymatic condensation of this formaldehyde with the indole substrates. The formation of THBCs in vivo has thus remained a point of contention. (PMID: 7213417). 1,2,3,4-Tetrahydro-beta-carboline is a biomarker for the consumption of beer
Tyramine is a monoamine compound derived from the amino acid tyrosine. Tyramine is metabolized by the enzyme monoamine oxidase. In foods, it is often produced by the decarboxylation of tyrosine during fermentation or decay. Foods containing considerable amounts of tyramine include fish, chocolate, alcoholic beverages, cheese, soy sauce, sauerkraut, and processed meat. A large dietary intake of tyramine can cause an increase in systolic blood pressure of 30 mmHg or more. Tyramine acts as a neurotransmitter via a G protein-coupled receptor with high affinity for tyramine called TA1. The TA1 receptor is found in the brain as well as peripheral tissues including the kidney. An indirect sympathomimetic, Tyramine can also serve as a substrate for adrenergic uptake systems and monoamine oxidase so it prolongs the actions of adrenergic transmitters. It also provokes transmitter release from adrenergic terminals. Tyramine is a biomarker for the consumption of cheese
This compound belongs to the family of Pyrimidine Nucleotide Sugars. These are pyrimidine nucleotides bound to a saccharide derivative through the terminal phosphate group.
Urocanic acid (CAS: 104-98-3) is a breakdown (deamination) product of histidine. In the liver, urocanic acid is an intermediate in the conversion of histidine to glutamic acid, whereas, in the epidermis, it accumulates and may be both a UV protectant and an immunoregulator. Urocanic acid (UA) exists as a trans isomer (t-UA, approximately 30 mg/cm2) in the uppermost layer of the skin (stratum corneum). t-UA is formed as the cells of the second layer of the skin become metabolically inactive. During this process, proteins and membranes degrade, histidine is released, and histidase (histidine ammonia lyase) catalyzes the deamination of histidine to form t-UA. t-UA accumulates in the epidermis until removal by either the monthly skin renewal cycle or sweat. Upon absorption of UV light, the naturally occurring t-UA isomerizes to its cis form, c-UA. Because DNA lesions (e.g., pyrimidine dimers) in the lower epidermis can result from UV-B absorption, initial research proposed that t-UA acted as a natural sunscreen absorbing UV-B in the stratum corneum before the damaging rays could penetrate into lower epidermal zones. Researchers have found that c-UA also suppresses contact hypersensitivity and delayed hypersensitivity, reduces the Langerhans cell count in the epidermis, prolongs skin-graft survival time, and affects natural killer cell activity. (E)-Urocanic acid is found in mushrooms. It has been isolated from Coprinus atramentarius (common ink cap) and Phallus impudicus (common stinkhorn).
Valaciclovir (INN) or valacyclovir (USAN) is an antiviral drug used in the management of herpes simplex and herpes zoster (shingles). It is a prodrug, being converted in vivo to aciclovir. It is marketed by GlaxoSmithKline under the trade name Valtrex or Zelitrex. [Wikipedia]
Valdecoxib is a prescription drug used in the treatment of osteoarthritis, rheumatoid arthritis, and painful menstruation and menstrual symptoms. It is classified as a nonsteroidal anti-inflammatory drug, or NSAID, and should not be taken by anyone allergic to these types of medications.
Valsartan is an angiotensin-receptor blocker (ARB) that may be used to treat a variety of cardiac conditions including hypertension, diabetic nephropathy and heart failure. Valsartan lowers blood pressure by antagonizing the renin-angiotensin-aldosterone system (RAAS); it competes with angiotensin II for binding to the type-1 angiotensin II receptor (AT1) subtype and prevents the blood pressure increasing effects of angiotensin II. Unlike angiotensin-converting enzyme (ACE) inhibitors, ARBs do not have the adverse effect of dry cough. Valsartan may be used to treat hypertension, isolated systolic hypertension, left ventricular hypertrophy and diabetic nephropathy. It may also be used as an alternative agent for the treatment of heart failure, systolic dysfunction, myocardial infarction and coronary artery disease.
Vanillin, also known as vanillaldehyde or lioxin, belongs to the class of organic compounds known as methoxyphenols. Methoxyphenols are compounds containing a methoxy group attached to the benzene ring of a phenol moiety. It is used by the food industry as well as ethylvanillin. Vanillin exists in all living species, ranging from bacteria to humans. Vanillin is a sweet, chocolate, and creamy tasting compound. Vanillin is found, on average, in the highest concentration within a few different foods, such as corns, ryes, and sherries and in a lower concentration in beers, rums, and oats. Vanillin has also been detected, but not quantified, in several different foods, such as gooseberries, other bread, brazil nuts, shea tree, and ohelo berries. This could make vanillin a potential biomarker for the consumption of these foods. Vanillin is a potentially toxic compound. Synthetic vanillin, instead of natural Vanillin extract, is sometimes used as a flavouring agent in foods, beverages, and pharmaceuticals. Vanillin is the primary component of the extract of the Vanillin bean. Because of the scarcity and expense of natural Vanillin extract, there has long been interest in the synthetic preparation of its predominant component. Artificial Vanillin flavoring is a solution of pure vanillin, usually of synthetic origin. Today, artificial vanillin is made from either guaiacol or from lignin, a constituent of wood which is a byproduct of the paper industry. The first commercial synthesis of vanillin began with the more readily available natural compound eugenol.
Vardenafil (Levitra) is an oral therapy for the treatment of erectile dysfunction. It is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5). Penile erection is a hemodynamic process initiated by the relaxation of smooth muscle in the corpus cavernosum and its associated arterioles. During sexual stimulation, nitric oxide is released from nerve endings and endothelial cells in the corpus cavernosum. Nitric oxide activates the enzyme guanylate cyclase resulting in increased synthesis of cyclic guanosine monophosphate (cGMP) in the smooth muscle cells of the corpus cavernosum. The cGMP in turn triggers smooth muscle relaxation, allowing increased blood flow into the penis, resulting in erection. The tissue concentration of cGMP is regulated by both the rates of synthesis and degradation via phosphodiesterases (PDEs). The most abundant PDE in the human corpus cavernosum is the cGMPspecific phosphodiesterase type 5 (PDE5); therefore, the inhibition of PDE5 enhances erectile function by increasing the amount of cGMP.
Verapamil is only found in individuals that have used or taken this drug. Verapamil is a calcium channel blocker that is a class IV anti-arrhythmia agent. [PubChem]Verapamil inhibits voltage-dependent calcium channels. Specifically, its effect on L-type calcium channels in the heart causes a reduction in ionotropy and chronotropy, thuis reducing heart rate and blood pressure. Verapamil's mechanism of effect in cluster headache is thought to be linked to its calcium-channel blocker effect, but which channel subtypes are involved is presently not known. [PubChem] Calcium channel antagonists can be quite toxic. In the management of poisoning, early recognition is critical. Calcium channel antagonists are frequently prescribed, and the potential for serious morbidity and mortality with over dosage is significant. Ingestion of these agents should be suspected in any patient who presents in an overdose situation with unexplained hypotension and conduction abnormalities. The potential for toxicity should be noted in patients with underlying hepatic or renal dysfunction who are receiving therapeutic doses. (PMID 8213877).
Vincristine is only found in individuals that have used or taken this drug. It is an antitumor alkaloid isolated from Vinca Rosea. (Merck, 11th ed.)The antitumor activity of Vincristine is thought to be due primarily to inhibition of mitosis at metaphase through its interaction with tubulin. Like other vinca alkaloids, Vincristine may also interfere with: 1) amino acid, cyclic AMP, and glutathione metabolism, 2) calmodulin-dependent Ca<sup>2+</sup>-transport ATPase activity, 3) cellular respiration, and 4) nucleic acid and lipid biosynthesis.
Vindesine is only found in individuals that have used or taken this drug. It is a vinblastine derivative with antineoplastic activity against cancer. Major side effects are myelosuppression and neurotoxicity. Vindesine is used extensively in chemotherapy protocols (antineoplastic combined chemotherapy protocols). [PubChem]Vindesine acts by causing the arrest of cells in metaphase mitosis through its inhibition tubulin mitotic funcitoning. The drug is cell-cycle specific for the S phase.
Nevirapine is only found in individuals that have used or taken this drug. It is a potent, non-nucleoside reverse transcriptase inhibitor used in combination with nucleoside analogues for treatment of HIV infection and AIDS. [PubChem]Nevirapine binds directly to reverse transcriptase (RT) and blocks the RNA-dependent and DNA-dependent DNA polymerase activities by causing a disruption of the enzyme's catalytic site. The activity of nevirapine does not compete with template or nucleoside triphosphates.
Vitexin, also known as apigenin 8-C-glucoside or 8-glycosylapigenin, belongs to the class of organic compounds known as flavonoid 8-C-glycosides. Flavonoid 8-C-glycosides are compounds containing a carbohydrate moiety which is C-glycosidically linked to 8-position of a 2-phenylchromen-4-one flavonoid backbone. Vitexin is also described as an apigenin flavone glucoside. Vitexin has been found in passion flower, chasteberry, bamboo leaves, millet and Hawthorn. Vitexin has shown a wide range of pharmacological effects, such as antioxidant, anti-cancer, anti-inflammatory, anti-hyperalgesic, and neuroprotective effects (PMID: 27693342). Vitexin has also been shown to directly inhibit thyroid peroxidase and potentially contributes to goiter (PMID: 1696490). It is sometimes called a goitrogen.
Voriconazole (Vfend, Pfizer) is a triazole antifungal medication used to treat serious fungal infections. It is used to treat invasive fungal infections that are generally seen in patients who are immunocompromised. These include invasive candidiasis, invasive aspergillosis, and emerging fungal infections.
Methoxsalen, also known as oxsoralen or 8-methoxypsoralen, belongs to the class of organic compounds known as 8-methoxypsoralens. These are psoralens containing a methoxy group attached at the C8 position of the psoralen group. Methoxsalen is a drug which is used for the treatment of psoriasis and vitiligo. Methoxsalen is a bitter tasting compound. Methoxsalen is found, on average, in the highest concentration within a few different foods, such as parsnips, parsley, and celery stalks and in a lower concentration in wild carrots, carrots, and fennels. Methoxsalen has also been detected, but not quantified, in several different foods, such as figs, green vegetables, corianders, dills, and fruits. Methoxsalen is a potentially toxic compound.
Zafirlukast is an oral leukotriene receptor antagonist (LTRA) for the maintenance treatment of asthma, often used in conjunction with an inhaled steroid and/or long-acting bronchodilator. It is available as a tablet and is usually dosed twice daily. Another leukotriene receptor antagonist is montelukast (Singulair), which is usually taken just once daily. Zafirlukast blocks the action of the cysteinyl leukotrienes on the CysLT1 receptors, thus reducing constriction of the airways, build-up of mucus in the lungs and inflammation of the breathing passages.
Zaleplon is a sedative/hypnotic, mainly used for insomnia. It is known as a nonbenzodiazepine hypnotic. Zaleplon interacts with the GABA receptor complex and shares some of the pharmacological properties of the benzodiazepines. Zaleplon is a schedule IV drug in the United States.
Leukotrienes are substances that induce numerous biological effects including augmentation of neutrophil and eosinophil migration, neutrophil and monocyte aggregation, leukocyte adhesion, increased capillary permeability, and smooth muscle contraction. These effects contribute to inflammation, edema, mucus secretion, and bronchoconstriction in the airways of asthmatic patients. Zileuton relieves such symptoms through its selective inhibition of 5-lipoxygenase, the enzyme that catalyzes the formation of leukotrienes from arachidonic acid. Specifically, it inhibits leukotriene LTB4, LTC4, LTD4, and LTE4 formation. Both the R(+) and S(-) enantiomers are pharmacologically active as 5-lipoxygenase inhibitors in in vitro systems.
Zolmitriptan is only found in individuals that have used or taken this drug. It is a synthetic tryptamine derivative and appears as a white powder that is readily soluble in water. [Wikipedia]Zolmitriptan binds with high affinity to human 5-HT<sub>1B</sub> and 5-HT<sub>1D</sub> receptors leading to cranial blood vessel constriction. Current theories proposed to explain the etiology of migraine headache suggest that symptoms are due to local cranial vasodilatation and/or to the release of sensory neuropeptides (vasoactive intestinal peptide, substance P and calcitonin gene-related peptide) through nerve endings in the trigeminal system. The therapeutic activity of zolmitriptan for the treatment of migraine headache can most likely be attributed to the agonist effects at the 5HT1B/1D receptors on intracranial blood vessels (including the arterio-venous anastomoses) and sensory nerves of the trigeminal system which result in cranial vessel constriction and inhibition of pro-inflammatory neuropeptide release.
Zolpidem (sold under the brand names Ambien, Ambien CR, Stilnox, and Sublinox) is a prescription medication used for the treatment of insomnia, as well as some brain disorders. It is a short-acting nonbenzodiazepine hypnotic of the imidazopyridine class that potentiates gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter, by binding to GABAA receptors at the same location as benzodiazepines. It works quickly (usually within 15 minutes) and has a short half-life (two to three hours). Zolpidem has not adequately demonstrated effectiveness in maintaining sleep (unless delivered in a controlled-release form); however, it is effective in initiating sleep. Some users take zolpidem recreationally for these side effects. However, it may be less common than benzodiazepine abuse. Zolpidem can become addictive if taken for extended periods of time, due to dependence on its ability to put one to sleep or to the euphoria it can sometimes produce.
xi-2,3-Dihydro-2-oxo-1H-indole-3-acetic acid is found in brassicas. xi-2,3-Dihydro-2-oxo-1H-indole-3-acetic acid is isolated from Ribes rubrum (currant), Brassica species and Helianthus annuus (sunflower). xi-2,3-Dihydro-2-oxo-1H-indole-3-acetic acid is a product of catabolism of 1H-Indole-3-acetic acid <ht>BNC14-M</ht> in Zea mays (sweetcorn
1,3,7-Trimethyluric acid is a methyl derivative of uric acid, found occasionally in human urine. 1,3,7-Trimethyluracil is one of the purine components in urinary calculi. Methylated purines originate from the metabolism of methylxanthines (caffeine, theophylline and theobromine). Methyluric acids are indistinguishable from uric acid by simple methods routinely used in clinical laboratories, requiring the use of high-performance liquid chromatography (HPLC). Purine derivatives in urinary calculi could be considered markers of abnormal purine metabolism. The content of a purine derivative in stone depends on its average urinary excretion in the general population, similarity to the chemical structure of uric acid, and content of the latter in stone. This suggests that purines in stones represent a solid solution with uric acid as solvent. It is also plausible that methylxanthines, ubiquitous components of the diet and drugs, are involved in the pathogenesis of urolithiasis. Caffeine is metabolized via successive pathways mainly catalyzed by CYP1A2, xanthine oxidase or N-acetyltransferase-2 to give 14 different metabolites. CYP1A2 activity shows an inter-individual variability among the population. CYP1A2, an isoform of the CYP1A cytochrome P450 super-family, is involved in the metabolism of many drugs and plays a potentially important role in the induction of chemical carcinogenesis. (PMID:11712316, 15833286, 3506820, 15013152).
1,7-Dimethyluric acid is the major urinary caffeine metabolite that is produced in the human body. 1,7-Dimethyluric acid is formed during caffeine metabolism and the process is catalyzed primarily by CYP2A6 (PMID: 18715882).
1-Methyladenosine, also known as M1A, belongs to the class of organic compounds known as purine nucleosides. Purine nucleosides are compounds comprising a purine base attached to a ribosyl or deoxyribosyl moiety. Precise m6A mapping by m6A-CLIP/IP (briefly m6A-CLIP) revealed that a majority of m6A locates in the last exon of mRNAs in multiple tissues/cultured cells of mouse and human, and the m6A enrichment around stop codons is a coincidence that many stop codons locate round the start of last exons where m6A is truly enriched. The methylation of adenosine is directed by a large m6A methyltransferase complex containing METTL3 as the SAM-binding sub-unit. Insulin-like growth factor-2 mRNA-binding proteins 1, 2, and 3 (IGF2BP1-3) are reported as a novel class of m6A readers.
1-Methylguanosine is a methylated nucleoside. It is known that some modified, especially methylated, nucleosides originating from RNA degradation are excreted in abnormal levels in the urine of patients with malignant tumours. These nucleosides have been proposed as tumour markers. Their measurement could provide a non-invasive diagnostic method, help identify different cancers, and monitor any therapeutic effects (PMID:9129323).
Estriol-16-glucuronide is a glucuronide derivative of the steroid estriol where the glucuronic acid is attached to the 16-hydroxyl group of Estriol. Glucuronidation is used to assist in the excretion of toxic substances, drugs or other substances that cannot be used as an energy source. Glucuronic acid is attached via a glycosidic bond to the substance, and the resulting glucuronide, which has a much higher water solubility than the original substance, is eventually excreted by the kidneys. Estriol (also known as oestriol) is one of the three main estrogens produced by the human body. It is only produced in significant amounts during pregnancy as it is made by the placenta.
A dideoxynucleoside compound in which the 3&#39;-hydroxy group on the sugar moiety has been replaced by a hydrogen. This modification prevents the formation of phosphodiester linkages which are needed for the completion of nucleic acid chains. Didanosine is a potent inhibitor of HIV replication, acting as a chain-terminator of viral DNA by binding to reverse transcriptase; ddI is then metabolized to dideoxyadenosine triphosphate, its putative active metabolite. [PubChem]
Deoxyadenosine is a derivative of the nucleoside adenosine. It is composed of adenine attached to a deoxyribose moiety via a N9-glycosidic bond. Deoxyribose differs from ribose by the absence of oxygen in the 3' position of its ribose ring. Deoxyadenosine is a critical component of DNA. When present in sufficiently high levels, deoxyadensoine can act as an immunotoxin and a metabotoxin. An immunotoxin disrupts, limits the function, or destroys immune cells. A metabotoxin is an endogenous metabolite that causes adverse health effects at chronically high levels. Chronically high levels of deoxyadenosine are associated with adenosine deaminase (ADA) deficiency, an inborn error of metabolism. ADA deficiency damages the immune system and causes severe combined immunodeficiency (SCID). People with SCID lack virtually all immune protection from bacteria, viruses, and fungi. They are prone to repeated and persistent infections that can be very serious or life-threatening. These infections are often caused by "opportunistic" organisms that ordinarily do not cause illness in people with a normal immune system. The main symptoms of ADA deficiency are pneumonia, chronic diarrhea, and widespread skin rashes. The mechanism by which dATP functions as an immunotoxin is as follows: because deoxyadenosine is a precursor to dATP, a buildup of dATP in cells inhibits ribonucleotide reductase and prevents DNA synthesis, so cells are unable to divide. Since developing T cells and B cells are some of the most mitotically active cells, they are unable to divide and propagate to respond to immune challenges. High levels of deoxyadenosine also lead to an increase in S-adenosylhomocysteine, which is toxic to immature lymphocytes.
Deoxyguanosine, also known as dG, belongs to the class of organic compounds known as purine 2'-deoxyribonucleosides. Purine 2'-deoxyribonucleosides are compounds consisting of a purine linked to a ribose which lacks a hydroxyl group at position 2‚Äô. Deoxyguanosine is a nucleoside consisting of the base guanine and the sugar deoxyribose. Deoxyguanosine is one of the four deoxyribonucleosides that make up DNA. Deoxyguanosine exists in all living species, ranging from bacteria to plants to humans. Deoxyguanosine participates in a number of enzymatic reactions. In particular, deoxyguanosine can be biosynthesized from 2'-deoxyguanosine 5'-monophosphate through the enzyme known as cytosolic purine 5'-nucleotidase. In addition, deoxyguanosine can be converted into 2'-deoxyguanosine 5'-monophosphate (dGMP); which is mediated by the enzyme deoxyguanosine kinase. Deoxyguanosine is involved in the rare, inherited metabolic disorder called the purine nucleoside phosphorylase deficiency (PNP deficiency). In particular PNP deficiency is characterized by elevated levels of dGTP (deoxyguanosine triphosphate). PNP accounts for approximately 4% of patients with severe combined immunodeficiency (PMID: 1931007). PNP-deficient patients suffer from recurrent infections, usually beginning in the first year of life. Two thirds of patients have evidence of neurologic disorders with spasticity, developmental delay and mental retardation. Deoxyguanosine can be converted to 8-hydroxy-deoxyguanosine (8-OHdG) due to hydroxyl radical attack at the C8 of guanine. 8-hydroxy-deoxyguanosine is a sensitive marker of the DNA damage This damage, if left unrepaired, has been proposed to contribute to mutagenicity and cancer promotion.
Deoxyuridine monophosphate (dUMP), also known as deoxyuridylic acid or deoxyuridylate in its conjugate acid and conjugate base forms, respectively, is a deoxynucleotide. It belongs to the class of organic compounds known as pyrimidine 2'-deoxyribonucleoside monophosphates. These are pyrimidine nucleotides with a monophosphate group linked to the ribose moiety lacking a hydroxyl group at position 2. dUMP exists in all living species, ranging from bacteria to humans. Within humans, dUMP participates in a number of enzymatic reactions. In particular, dUMP can be biosynthesized from dCMP through its interaction with the enzyme deoxycytidylate deaminase. In addition, dUMP can be biosynthesized from deoxyuridine; which is mediated by the enzyme thymidine kinase, cytosolic. In humans, dUMP is involved in pyrimidine metabolism. A pyrimidine 2'-deoxyribonucleoside 5'-monophosphate having uracil as the nucleobase. Outside of the human body, dUMP has been detected, but not quantified in several different foods, such as breadnut tree seeds, sea-buckthornberries, sour cherries, black walnuts, and common oregano.
Deoxyuridine, also known as dU, belongs to the class of organic compounds known as pyrimidine 2'-deoxyribonucleosides. Pyrimidine 2'-deoxyribonucleosides are compounds consisting of a pyrimidine linked to a ribose which lacks a hydroxyl group at position 2. It is similar in chemical structure to uridine, but without the 2'-hydroxyl group. Deoxyuridine exists in all living organisms, ranging from bacteria to humans. Within humans, deoxyuridine participates in a number of enzymatic reactions. In particular, deoxyuridine can be biosynthesized from deoxycytidine through its interaction with the enzyme cytidine deaminase. In addition, deoxyuridine can be converted into uracil and deoxyribose 1-phosphate through its interaction with the enzyme thymidine phosphorylase. Deoxyuridine is considered to be an antimetabolite that is converted into deoxyuridine triphosphate during DNA synthesis. Laboratory suppression of deoxyuridine is used to diagnose megaloblastic anemia due to vitamin B12 and folate deficiencies. In humans, deoxyuridine is involved in the metabolic disorder called UMP synthase deficiency (orotic aciduria). Outside of the human body, deoxyuridine has been detected, but not quantified in, several different foods, such as lichee, highbush blueberries, agaves, macadamia nut (M. tetraphylla), and red bell peppers. This could make deoxyuridine a potential biomarker for the consumption of these foods.
2'-O-Methyluridine belongs to the class of organic compounds known as pyrimidine nucleosides. Pyrimidine nucleosides are compounds comprising a pyrimidine base attached to a ribosyl or deoxyribosyl moiety. 2'-O-Methyluridine was identified as one of forty plasma metabolites that could be used to predict gut microbiome Shannon diversity (PMID: 31477923). Shannon diversity is a metric that summarizes both species abundance and evenness, and it has been suggested as a marker for microbiome health.
2-Pyrocatechuic acid is a normal human benzoic acid metabolite found in plasma (PMID 16351159), and is normally found with increased levels after consumption of many nutrients and drugs, i.e.: cranberry juice (PMID 14733499), aspirin ingestion. (PMID 3342084) It has been found associated with idiopathic oro-facial pain due to stress (oxidative stress might enhance the production of free radicals); it has been suggested that OH radicals are responsible for the production of many systemic and local tissue injury diseases which may initially manifest as pain syndrome, and 2-Pyrocatechuic acid is a biological marker for the detection and quantification of OH radicals, and patients had significantly increased circulating levels of 2-Pyrocatechuic acid after aspirin ingestion than control subjects. (PMID 7748148).
2,4-D is a member of the phenoxy family of herbicides, which include:; 2,4-D is a synthetic auxin, which is a class of plant hormones. It is absorbed through the leaves and is translocated to the meristems of the plant. Uncontrolled, unsustainable growth ensues, causing stem curl-over, leaf withering, and eventual plant death. 2,4-D is typically applied as an amine salt, but more potent ester versions exist as well. 2,4-Dichlorophenoxyacetic acid (usually referred to by its abbreviation, 2,4-D) is a common systemic pesticide/herbicide used in the control of broadleaf weeds. It is one of the most widely used herbicide in the world, and the third most commonly used in North America. 2,4-D is a synthetic auxin (plant hormone), and as such it is often used in laboratories for plant research and as a supplement in plant cell culture media such as MS medium. It was a major ingredient in Agent Orange alongside its chemically similar relative, 2,4,5-T (2,4,5-trichlorophenoxyacetic acid).
Gentisate aldehyde is a substrate of the enzyme aldehyde oxidase 1 [EC:1.2.3.1] in Valine, leucine and isoleucine degradation, Tyrosine metabolism, Tryptophan metabolism, Vitamin B6 metabolism and Nicotinate and nicotinamide metabolism. (KEGG).
2,8-Quinolinediol, also known as quinoline-2,8-diol or 8-hydroxycarbostyril, belongs to the class of organic compounds known as quinolones and derivatives. Quinolones and derivatives are compounds containing a quinoline moiety that bears a ketone group. 2,8-Quinolinediol has been identified in urine (PMID: 30089834).
This compound belongs to the family of M-methoxybenzoic Acids and Derivatives. These are benzoic acids  in which the hydrogen atom at position 3 of the benzene ring is replaced by a methoxy group
Deoxycytidine monophosphate (dCMP), also known as deoxycytidylic acid or deoxycytidylate in its conjugate acid and conjugate base forms, respectively, is a deoxynucleotide, and one of the four monomers that make up DNA. In a DNA double helix, it will base pair with deoxyguanosine monophosphate. dCMP belongs to the class of organic compounds known as pyrimidine 2'-deoxyribonucleoside monophosphates. These are pyrimidine nucleotides with a monophosphate group linked to the ribose moiety lacking a hydroxyl group at position 2. Deficiency of the enzyme deoxycytidine kinase (EC2.7.1.74) is associated with resistance to antiviral and anticancer chemotherapeutic agents, whereas increased enzyme activity is associated with increased activation of these compounds to cytotoxic nucleoside triphosphate derivatives. dCMP exists in all living species, ranging from bacteria to humans. Within humans, dCMP participates in a number of enzymatic reactions. In particular, dCMP can be converted to dCDP by the enzyme UMP-CMP kinase 2. In addition, dCMP can be converted into deoxycytidine, which is catalyzed by the enzyme cytosolic purine 5'-nucleotidase. In humans, dCMP is involved in the metabolic disorder called ump synthase deficiency (orotic aciduria). Outside of the human body, dCMP has been detected, but not quantified in several different foods, such as turnips, garlics, agaves, garden onions, and italian sweet red peppers. dCMP is a deoxycytosine nucleotide containing one phosphate group esterified to the deoxyribose moiety in the 2'-,3'- or 5- positions.
Furoic acid is a metabolite that appears in the urine of workers occupationally exposed to furfural and is a marker of exposure to this compound. Furfural is a heterocyclic aldehyde that is commonly used as a solvent in industry. It is readily absorbed into the body via the lungs and has significant skin absorption. Furfural is an irritant of the eyes, mucous membranes, and skin and is a central nervous system depressant. Furfural as a confirmed animal carcinogen with unknown relevance to humans (It has been suggested that is a substance that produces hepatic cirrhosis). Once in the body, furfural is metabolized rapidly via oxidation to the metabolite furoic acid, which is then conjugated with glycine and excreted in the urine in both free and conjugated forms. (PMID: 3751566, 4630229, 12587683). 2-Furoic acid is a biomarker for the consumption of beer
2-Hydroxy-3-methylbutyric acid (also known as 2-hydroxyisovaleric acid) is a metabolite found in the urine of patients with phenylketonuria (PMID: 7978272), methylmalonic acidemia, propionic acidemia, 3-ketothiolase deficiency, isovaleric acidemia, 3-methylcrotonylglycemia, 3-hydroxy-3-methylglutaric acidemia, multiple carboxylase deficiency, glutaric aciduria, ornithine transcarbamylase deficiency, glyceroluria, tyrosinemia type I, galactosemia, and maple syrup urine disease (PMID: 11048741). 2-Hydroxyisovaleric acid has also been identified in the urine of patients with lactic acidosis and ketoacidosis (PMID: 884872), and in the urine of severely asphyxiated babies (PMID: 1610944). 2-Hydroxyisovaleric acid originates mainly from ketogenesis and from the metabolism of valine, leucine, and isoleucine (PMID: 6434570). 2-Hydroxy-3-methylbutyric acid has been identified in the human placenta (PMID: 32033212).
Leucinic acid, also known as leucic acid, 2-hydroxyisocaproic acid or 2-hydroxy-4-methylvaleric acid, belongs to the class of organic compounds known as hydroxy fatty acids. These are fatty acids in which the chain bears a hydroxyl group. Leucinic acid is a valeric acid derivative having a hydroxy substituent at the 2-position and a methyl substituent at the 4-position. It is an alpha-hydroxy analogue of leucine and a metabolite of the branched-chain amino acid leucine. Leucinic acid is found in all organisms ranging from bacteria to plants to animals. Leucinic acid has been found in a patient with dihydrolipoyl dehydrogenase (DLD) deficiency (PMID: 6688766). DLD deficiency is caused by mutations in the DLD gene and is inherited in an autosomal recessive manner. A common feature of dihydrolipoamide dehydrogenase deficiency is a potentially life-threatening buildup of lactic acid in tissues (lactic acidosis), which can cause nausea, vomiting, severe breathing problems, and an abnormal heartbeat. Neurological problems are also common in this condition; the first symptoms in affected infants are often decreased muscle tone (hypotonia) and extreme tiredness (lethargy). As the problems worsen, affected infants can have difficulty feeding, decreased alertness, and seizures. Liver problems can also occur in dihydrolipoamide dehydrogenase deficiency, ranging from an enlarged liver (hepatomegaly) to life-threatening liver failure. In some affected people, liver disease, which can begin anytime from infancy to adulthood, is the primary symptom. Leucinic acid is also present in the urine of patients with short bowel syndrome (PMID: 4018104)
2-Hydroxybenzaldehyde, also known as salicylal or O-formylphenol, belongs to the class of organic compounds known as hydroxybenzaldehydes. These are organic aromatic compounds containing a benzene ring carrying an aldehyde group and a hydroxyl group. 2-Hydroxybenzaldehyde is a cinnamon, cooling, and medical tasting compound. 2-Hydroxybenzaldehyde is found, on average, in the highest concentration within peppermints. 2-Hydroxybenzaldehyde has also been detected, but not quantified, in several different foods, such as common buckwheats, garden tomato (var.), herbs and spices, and tea. This could make 2-hydroxybenzaldehyde a potential biomarker for the consumption of these foods. 2-Hydroxybenzaldehyde is a potentially toxic compound.
2-coumaric acid, also known as o-coumaric acid, is a monohydroxycinnamic acid in which the hydroxy substituent is located at C-2 of the phenyl ring. It has a role as a plant metabolite. It is a conjugate acid of a 2-coumarate. It is a hydroxycinnamic acid, an organic compound that is a hydroxy derivative of cinnamic acid. There are three isomers of coumaric acids: o-coumaric acid, m-coumaric acid, and p-coumaric acid, that differ by the position of the hydroxy substitution of the phenyl group. 2-Hydroxycinnamic acid belongs to the class of organic compounds known as hydroxycinnamic acids. Hydroxycinnamic acids are compounds containing an cinnamic acid where the benzene ring is hydroxylated. 2-Hydroxycinnamic acid exists in all living organisms, ranging from bacteria to humans. 2-Hydroxycinnamic acid has been found in a few different foods, such as corns, hard wheats, and olives and in a lower concentration in pomegranates, american cranberries, and peanuts. 2-Hydroxycinnamic acid has also been detected, but not quantified in several different foods, such as carrots, soy beans, ryes, rye bread, and turmerics.
alpha-Hydroxyisobutyric acid is a metabolite of methyl tert-butyl ether (MTBE). MTBE may be obtained through environmental exposure. MTBE is rapidly eliminated from the body, mainly through expired air as the unchanged compound. MTBE is to some extent metabolized to t-butyl alcohol (TBA) and formaldehyde and oxidized to 2-methyl-1,2-propanediol and alpha-hydroxyisobutyric acid. alpha-Hydroxyisobutyric acid has been used as an aerial bactericide.
ortho-Hydroxyphenylacetic acid, also known as (o-hydroxyphenyl)acetate or 2-hydroxybenzeneacetic acid, is a member of the class of compounds known as 2(hydroxyphenyl)acetic acids. 2(Hydroxyphenyl)acetic acids are phenylacetic acids that carry a hydroxyl group at the 2-position. ortho-Hydroxyphenylacetic acid is slightly soluble (in water) and a weakly acidic compound (based on its pKa). ortho-Hydroxyphenylacetic acid can be found in a number of food items such as natal plum, lemon verbena, half-highbush blueberry, and parsley, which makes ortho-hydroxyphenylacetic acid a potential biomarker for the consumption of these food products. ortho-Hydroxyphenylacetic acid can be found primarily in blood, feces, and urine. Moreover, ortho-hydroxyphenylacetic acid is found to be associated with phenylketonuria, which is an inborn error of metabolism. ortho-Hydroxyphenylacetic acid is a substrate of the enzyme oxidoreductases (EC 1.14.13.-) in the pathway styrene degradation (KEGG). ortho-Hydroxyphenylacetic acid is also a microbial metabolite.
2-Methoxy-4-vinylphenol is an aromatic substance used as a flavoring agent. It is one of the compounds responsible for the natural aroma of buckwheat.
2-Methylglutaric acid, also known as alpha-methylglutarate or 2-methylpentanedioate, belongs to the class of organic compounds known as methyl-branched fatty acids. These are fatty acids with an acyl chain that has a methyl branch. Usually, they are saturated and contain only one or more methyl group. However, branches other than methyl may be present. 2-Methylglutaric acid is also classified as an alpha,omega-dicarboxylic acid. It is glutaric acid substituted at position 2 by a methyl group. 2-Methylglutaric acid arises from the microbial metabolism of the isoprenoid alkaloid pristane (PMID: 4327007; PMID: 20143352).
Propionylglycine is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acyl glycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13) which is an enzyme that catalyzes the chemical reaction:acyl-CoA + glycine < -- > CoA + N-acylglycineThe level of propionylglycine is elevated in patients with propionic acidemia, which is an inherited deficiency of propionyl-CoA carboxylase. (Disorders of propionate and methylmalonate metabolism. In The Metabolic and Molecular Bases of Inherited Disease).
3-Methylcytidine belongs to the class of organic compounds known as pyrimidine nucleosides. These are compounds comprising a pyrimidine base attached to a ribosyl or deoxyribosyl moiety. 3-Methylcytidine is a potential urinary biomarker of whole grain intake (PMID: 27805021). 3-Methylcytidine has been identified in the human placenta (PMID: 32033212).
3'-O-Methylguanosine is an endogenous methylated nucleoside found in human fluids. Methylated purine bases are present in higher amounts in tumor-bearing patients compared to healthy controls. DNA hypermethylation is a common finding in malignant cells and has been explored as a therapeutic target for hypomethylating agents. When chemical bonds to DNA, it becomes damaged and proper and complete replication cannot occur to make the normal intended cell. A DNA adduct is an abnormal piece of DNA covalently-bonded to a cancer-causing chemical. This has shown to be the start of a cancerous cell, or carcinogenesis. DNA adducts in scientific experiments are used as bio-markers and as such are themselves measured to reflect quantitatively, for comparison, the amount of cancer in the subject. (PMID: 3506820, 17044778, 17264127, 16799933).
Protocatechuic acid, also known as protocatechuate or 3,4-dihydroxybenzoate, belongs to the class of organic compounds known as hydroxybenzoic acid derivatives. Hydroxybenzoic acid derivatives are compounds containing a hydroxybenzoic acid (or a derivative), which is a benzene ring bearing a carboxyl and a hydroxyl groups. The enzyme protocatechuate 3,4-dioxygenase uses 3,4-dihydroxybenzoate and O2 to produce 3-carboxy-cis,cis-muconate. Protocatechuic acid is a drug. In the analogous hardening of the cockroach ootheca, the phenolic substance concerned is protocatechuic acid. Protocatechuic acid is a mild, balsamic, and phenolic tasting compound. Outside of the human body, protocatechuic acid is found, on average, in the highest concentration in a few different foods, such as garden onions, cocoa powders, and star anises and in a lower concentration in lentils, liquors, and red raspberries. Protocatechuic acid has also been detected, but not quantified in several different foods, such as cloud ear fungus, american pokeweeds, common mushrooms, fruits, and feijoa. This could make protocatechuic acid a potential biomarker for the consumption of these foods. It is also found in Allium cepa (17,540 ppm). It is a major metabolite of antioxidant polyphenols found in green tea. Similarly, PCA was reported to increase proliferation and inhibit apoptosis of neural stem cells. In vitro testing documented antioxidant and anti-inflammatory activity of PCA, while liver protection in vivo was measured by chemical markers and histological assessment.
L-2-Amino-3-(1-pyrazolyl)propanoic acid is found in fruits. L-2-Amino-3-(1-pyrazolyl)propanoic acid is a amino acid present in seeds of Citrullus vulgaris (watermelon
3-(2-Hydroxyphenyl)propanoic acid is found in bilberry. 3-(2-Hydroxyphenyl)propanoic acid is found in Melilotus alba (whilte melilot).
3-(3-Hydroxyphenyl)propanoic (hMPP) acid is one of the major metabolites of ingested caffeic acid (PMID: 15479001) and of the phenolic degradation products of proanthocyanidins (the most abundant polyphenol present in chocolate) by the microflora in the colon (PMID: 12663291). mHPP is suspected to have antioxidants properties and is actively absorbed by the monocarboxylic acid transporter (MCT) in intestinal Caco-2 cell monolayers (PMID: 15479001, 12663291). hMPP has been found to be a metabolite of Clostridium, Escherichia, and Eubacterium (PMID: 28393285, 19520845). 3-(3-Hydroxyphenyl)propanoic acid is a flavonoid metabolite. 3-(3-Hydroxyphenyl)propanoic acid is a phenolic acid metabolite formed by the gut microflora detected after the consumption of whole grain.
Hydroxyphenyllactic acid or 4-hydroxyphenyllactate (the L-form) is a tyrosine metabolite. The level of L-hydroxyphenyllactic acid is elevated in patients with a deficiency of the enzyme p-hydroxyphenylpyruvate oxidase (EC 1.14.2.2) (PMID: 4720815). L-hydroxyphenyllactate is present in relatively higher concentrations in the cerebrospinal fluid and urine of patients with phenylketonuria (PKU) and tyrosinemia (PMID: 3126358). However, the D-form of hydroxyphenyllactate is of bacterial origin and is also found in individuals with bacterial overgrowth or unusual gut microflora (PMID: 3126358).  Microbial hydroxyphenyllactate is likely derived from phenolic or polyphenolic compounds in the diet.  Bifidobacteria and lactobacilli produce considerable amounts of phenyllactic and p-hydroxyphenyllactic acids (PMID: 23061754).  It has also been shown that hydroxyphenyllactate decreases ROS (reactive oxygen species) production in both mitochondria and neutrophils and so hydroxyphenyllactate may function as a natural anti-oxidant (PMID: 23061754). Hydroxyphenyllactic acid is a microbial metabolite found in Acinetobacter, Bacteroides, Bifidobacteria, Bifidobacterium, Clostridium, Enterococcus, Escherichia, Eubacterium, Klebsiella, Lactobacillus, Pseudomonas and Staphylococcus (PMID: 19961416).
3-Hydroxybenzyl alcohol (CAS Number 620-24-6) is a hydroxybenzyl alcohol that is phenol substituted at position C-3 by a hydroxymethyl group. It is a pink or beige to brown crystalline powder, soluble in water.
The use of tyrosine kinase receptor inhibitors is increasingly becoming a valuable therapeutic alternative in tumors carrying activated tyrosine kinase receptors. GMR beta tyrosine residues are not necessary for activation of the JAK/STAT pathway, or for proliferation, viability, or adhesion signaling in Ba/F3 cells, although tyrosine residues significantly affect the magnitude of the response. (PMID:10372132).
3-Hydroxyanthranilic acid, also known as 2-amino-3-hydroxy-benzoate or 3-ohaa, belongs to the class of organic compounds known as hydroxybenzoic acid derivatives. Hydroxybenzoic acid derivatives are compounds containing a hydroxybenzoic acid (or a derivative), which is a benzene ring bearing a carboxyl and a hydroxyl groups. 3-Hydroxyanthranilic acid is a drug. 3-Hydroxyanthranilic acid exists in all living species, ranging from bacteria to humans. Within humans, 3-hydroxyanthranilic acid participates in a number of enzymatic reactions. In particular, 3-hydroxyanthranilic acid and L-alanine can be biosynthesized from L-3-hydroxykynurenine through the action of the enzyme kynureninase. In addition, 3-hydroxyanthranilic acid can be converted into cinnavalininate through the action of the enzyme catalase. 3-Hydroxyanthranilic acid is an intermediate in the metabolism of tryptophan. In humans, 3-hydroxyanthranilic acid is involved in tryptophan metabolism. Outside of the human body, 3-hydroxyanthranilic acid has been detected, but not quantified in brassicas. This could make 3-hydroxyanthranilic acid a potential biomarker for the consumption of these foods. It is new antioxidant isolated from methanol extract of tempeh. It is effective in preventing autoxidation of soybean oil and powder, while antioxidant 6,7,4'-trihydroxyisoflavone is not.
3-Hydroxyphenylacetic acid is a rutin metabolite and an antioxidant. It has a protective biological activity in human. It is a substrate of enzyme 4-hydroxyphenylacetate 3-monooxygenase [EC 1.14.13.3] in the pathway tyrosine metabolism (KEGG, PMID 155437). 3-Hydroxyphenylacetic acid is found to be associated with phenylketonuria, which is an inborn error of metabolism. It is also a marker of gut Clostridium species. Higher levels are associated with higher levels of Clostridia (PMID: 27123458). 3-Hydroxyphenylacetic acid can also be found in Klebsiella (PMID: 1851804).
3-Hydroxyvaleric acid may be products of the condensation of propionyl-CoA with acetyl-CoA catalyzed by 3-oxoacyl-CoA thiolases. An increase amount of 3-hydroxyvaleric acid can be found in methylmalonic acidemia and propionic acidemia. (PMID: 630060).
3-Indoleacetonitrile is a phytoalexin. Phytoalexins are antibiotics produced by plants that are under attack. Phytoalexins tend to fall into several classes including terpenoids, glycosteroids, and alkaloids; however, researchers often find it convenient to extend the definition to include all phytochemicals that are part of the plant's defensive arsenal. Phytoalexins produced in plants act as toxins to the attacking organism. They may puncture the cell wall, delay maturation, disrupt metabolism, or prevent the reproduction of the pathogen in question. However, phytoalexins are often targeted to specific predators; a plant that has anti-insect phytoalexins may not have the ability to repel a fungal attack. 3-Indoleacetonitrile is common in cruciferous vegetables such as cabbage, cauliflower, broccoli, and Brussels sprouts. Dietary indoles in cruciferous vegetables induce cytochrome P450 enzymes and have prevented tumours in various animal models. Consumption of Brassica vegetables is associated with a reduced risk of cancer of the alimentary tract in animal models and human populations (PMID:15612779, 15884814, 2342128, 3014947, 3880668, 6334634, 6419397, 6426808, 6584878, 6725517, 6838646, 7123561).
3-methylcatechol, also known as 2,3-dihydroxytoluene or 2,3-toluenediol, is a member of the class of compounds known as catechols. Catechols are compounds containing a 1,2-benzenediol moiety. 3-methylcatechol is soluble (in water) and a very weakly acidic compound (based on its pKa). 3-methylcatechol can be found in arabica coffee, beer, cocoa powder, and coffee, which makes 3-methylcatechol a potential biomarker for the consumption of these food products. 3-methylcatechol is a chemical compound .
3-Methylcrotonylglycine is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acyl glycines are produced through the action of glycine N-acyltransferase (EC 2.3.1.13) which is an enzyme that catalyzes the chemical reaction: acyl-CoA + glycine < -- > CoA + N-acylglycine. 3-Methylcrotonylglycine is a normal amino acid metabolite found in urine. Increased levels of this metabolite are found in patients suffering from leucine catabolic disorders, such as 3-methylcrotonyl-CoA carboxylase deficiency. 3-Methylcrotonylglycine is often considered to be a diagnostic marker of organic acidemias (PMID 11170888). Moreover, 3-methylcrotonylglycine is found to be associated with 3-hydroxy-3-methylglutaryl-CoA lyase deficiency and propionic acidemia, which are also inborn errors of metabolism.
Methylglutaric acid is a leucine metabolite. A large amount of methylglutaric acid is identified in urine of patients with deficiency of 3-methylglutaconyl coenzyme A hydratase (PMID 6181239). Methylglutaric acid is also found to be associated with 3-hydroxy-3-methylglutaryl-CoA lyase deficiency, another inborn error of metabolism.
3-Nitrotyrosine, also known as nitrotyrosine is a product of tyrosine nitration mediated by reactive nitrogen species such as peroxynitrite anion and nitrogen dioxide. Nitrotyrosine is identified as an indicator or marker of cell damage, inflammation as well as NO (nitric oxide) production. Nitrotyrosine is formed in the presence of the active metabolite NO. Nitrotyrosine belongs to the class of organic compounds known as tyrosine and derivatives. Tyrosine and derivatives are compounds containing tyrosine or a derivative thereof resulting from reaction of tyrosine at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom.
Phenyllactic acid is a product of phenylalanine catabolism. An elevated level of phenyllactic acid is found in body fluids of patients with or phenylketonuria.
4-Acetamidobutanoic acid, also known as 4-acetamidobutanoate or N-acetyl-4-aminobutyric acid, is a member of the class of compounds known as gamma amino acids and derivatives. These compounds are amino acids having an -NH2 group attached to the gamma carbon atom. 4-Acetamidobutanoic acid is soluble in water. 4-Acetamidobutanoic acid can be found in a number of food items such as Rubus species (blackberry, raspberry), cassava, pepper (Capsicum frutescens), and napa cabbage, which makes 4-acetamidobutanoic acid a potential biomarker for the consumption of these food products. 4-Acetamidobutanoic acid can be found in blood, feces, and urine, as well as in human prostate tissue. 4-Acetamidobutanoic acid exists in all eukaryotes, ranging from yeast to humans. 4-Acetamidobutanoic acid is a GABA derivative, a product of the urea cycle and the metabolism of amino groups, and the product of NAD-linked aldehyde dehydrogenase (EC 1.2.1.3) (KEGG).
4-Guanidinobutanoic acid, also known as gamma-guanidinobutyrate or 4-(carbamimidamido)butanoate, belongs to the class of organic compounds known as gamma amino acids and derivatives. These are amino acids having a (-NH2) group attached to the gamma carbon atom. 4-Guanidinobutanoic acid is a normal metabolite present in low concentrations. 4-Guanidinobutanoic acid exists in all eukaryotes, ranging from yeast to humans. Outside of the human body, 4-Guanidinobutanoic acid has been detected, but not quantified in a few different foods, such as apples, french plantains, and loquats. This could make 4-guanidinobutanoic acid a potential biomarker for the consumption of these foods. Patients with hyperargininemia have an arginase deficiency which leads to blockade of the urea cycle in the last step with several clinical symptoms. Owing to the arginase deficiency this patients accumulate arginine which leads eventually to epileptogenic guanidino compounds (PMID 7752905).
Hexylresorcinol, also known as adrover or antascarin, belongs to the class of organic compounds known as resorcinols. Resorcinols are compounds containing a resorcinol moiety, which is a benzene ring bearing two hydroxyl groups at positions 1 and 3. The agent also demonstrates mild antiseptic activity as well as an apparent anti-inflammatory, demulcent action . Moreover, such studies have also shown that hexylresorcinol is seemingly capable of dose-dependent induction of SCC-9 cell apoptosis as well as the inhibition of transglutaminase-2 enzyme activity which can facilitate chemotherapy resistance . Hexylresorcinol is a potentially toxic compound. Hexylresorcinol belongs to the family of Resorcinols. Regarding the metabolism of hexylresorcinol, it has been reported that excretion of the compound in the urine is largely in the form of an ethereal sulfate conjugate. Ultimately, it is also reported that glutathione depletion increases tyrosinase activity in human melanoma cells, which makes hexylresorcinol's effects on tyrosinase desirable . Nevertheless, it is useful for hexylresorcinol to have both anesthetic and certain antiseptic actions for its use in treating various relatively self-limiting scrapes and sore throats that are treated by the over-the-counter products that feature the compound. It is proposed that hexylresorcinol can bind to tyrosinase directly and inhibits its enzyme activity . It can be found in topical applications for minor skin infections and in oral solutions or throat lozenges for pain relief and first aid antiseptic.
4-Hydroxybenzaldehyde, also known as 4-formylphenol or 4-hydroxybenzenecarbonal, belongs to the class of organic compounds known as hydroxybenzaldehydes. These are organic aromatic compounds containing a benzene ring carrying an aldehyde group and a hydroxyl group. A hydroxybenzaldehyde that is benzaldehyde substituted with a hydroxy group at position C-4. 4-Hydroxybenzaldehyde exists in all living organisms, ranging from bacteria to humans. 4-Hydroxybenzaldehyde is a sweet, almond, and balsam tasting compound. 4-Hydroxybenzaldehyde is found, on average, in the highest concentration within vinegars and oats. 4-Hydroxybenzaldehyde has also been detected, but not quantified, in several different foods, such as cardoons, colorado pinyons, oyster mushrooms, common chokecherries, and potato. This could make 4-hydroxybenzaldehyde a potential biomarker for the consumption of these foods.
4-Hydroxybenzeneacetonitrile is found in herbs and spices. 4-Hydroxybenzeneacetonitrile is isolated from white mustard (Brassica alba) as a decomposition product of 4-Hydroxybenzyl glucosinolate <ht>KZZ54-K</ht>
4-Hydroxycinnamic acid, also known as p-Coumaric acid, is a coumaric acid in which the hydroxy substituent is located at C-4 of the phenyl ring. It has a role as a plant metabolite. It is a conjugate acid of a 4-coumarate. p-coumaric acid is an organic compound that is a hydroxy derivative of cinnamic acid. There are three isomers of coumaric acid: o-coumaric acid, m-coumaric acid, and p-coumaric acid, that differ by the position of the hydroxy substitution of the phenyl group. p-Coumaric acid is the most abundant isomer of the three in nature. p-Coumaric acid exists in two forms trans-p-coumaric acid and cis-p-coumaric acid. It is a crystalline solid that is slightly soluble in water, but very soluble in ethanol and diethyl ether. 4-Hydroxycinnamic acid belongs to the class of organic compounds known as hydroxycinnamic acids. Hydroxycinnamic acids are compounds containing an cinnamic acid where the benzene ring is hydroxylated. 4-Hydroxycinnamic acid exists in all living species, ranging from bacteria to humans. Outside of the human body, 4-Hydroxycinnamic acid is found, on average, in the highest concentration within a few different foods, such as pepper (Capsicum frutescens), pineapples, and sunflowers and in a lower concentration in spinachs, kiwis, and sweet oranges. 4-Hydroxycinnamic acid has also been detected, but not quantified in several different foods, such as wild rices, soursops, garden onions, hyssops, and avocado.
4-Hydroxyhippuric acid is a microbial end-product derived from polyphenol metabolism by the microflora in the intestine (PMID: 22932811). It is derived from 4-hydroxybenzoic acid derivatives which may undergo glycination in the liver and kidney (PMID: 20615997). 4-Hydroxyhippuric acid has been identified in the human placenta (PMID: 32033212).
p-Hydroxymandelic acid is an acidic metabolite of p-octopamine and p-synephrine (p-phenylephrine). It is also a naturally occurring metabolite of tyramine. A specific enantiomer of p-hydroxymandelic aicd ((R)-(-)-p-hydroxymandelic -- also called pisolithin B) has been shown to exhibit antifungal properties.
p-Hydroxyphenylacetic acid, also known as 4-hydroxybenzeneacetate, is classified as a member of the 1-hydroxy-2-unsubstituted benzenoids. 1-Hydroxy-2-unsubstituted benzenoids are phenols that are unsubstituted at the 2-position. p-Hydroxyphenylacetic acid is considered to be slightly soluble (in water) and acidic.  p-Hydroxyphenylacetic acid can be synthesized from acetic acid. It is also a parent compound for other transformation products, including but not limited to, methyl 2-(4-hydroxyphenyl)acetate, ixerochinolide, and lactucopicrin 15-oxalate.  p-Hydroxyphenylacetic acid can be found in numerous foods such as olives, cocoa beans, oats, and mushrooms. p-Hydroxyphenylacetic acid can be found throughout all human tissues and in all biofluids. Within a cell, p-hydroxyphenylacetic acid is primarily located in the cytoplasm and in the extracellular space. p-Hydroxyphenylacetic acid is also a microbial metabolite produced by Acinetobacter, Clostridium, Klebsiella, Pseudomonas, and Proteus. Higher levels of this metabolite are associated with an overgrowth of small intestinal bacteria from Clostridia species including C. difficile, C. stricklandii, C. lituseburense, C. subterminale, C. putrefaciens, and C. propionicum (PMID: 476929, 12173102). p-Hydroxyphenylacetic acid is detected after the consumption of whole grain.
Hydroxyphenyllactic acid or 4-hydroxyphenyllactate (the L-form) is a tyrosine metabolite. The level of L-hydroxyphenyllactic acid is elevated in patients with a deficiency of the enzyme p-hydroxyphenylpyruvate oxidase (EC 1.14.2.2) (PMID: 4720815). L-hydroxyphenyllactate is present in relatively higher concentrations in the cerebrospinal fluid and urine of patients with phenylketonuria (PKU) and tyrosinemia (PMID: 3126358). However, the D-form of hydroxyphenyllactate is of bacterial origin and is also found in individuals with bacterial overgrowth or unusual gut microflora (PMID: 3126358).  Microbial hydroxyphenyllactate is likely derived from phenolic or polyphenolic compounds in the diet.  Bifidobacteria and lactobacilli produce considerable amounts of phenyllactic and p-hydroxyphenyllactic acids (PMID: 23061754).  It has also been shown that hydroxyphenyllactate decreases ROS (reactive oxygen species) production in both mitochondria and neutrophils and so hydroxyphenyllactate may function as a natural anti-oxidant (PMID: 23061754). Hydroxyphenyllactic acid is a microbial metabolite found in Acinetobacter, Bacteroides, Bifidobacteria, Bifidobacterium, Clostridium, Enterococcus, Escherichia, Eubacterium, Klebsiella, Lactobacillus, Pseudomonas and Staphylococcus (PMID: 19961416).
4-Hydroxyphenylpyruvic acid (4-HPPA) is a keto acid that is involved in the tyrosine catabolism pathway. It is a product of the enzyme (R)-4-hydroxyphenyllactate dehydrogenase (EC 1.1.1.222) and is formed during tyrosine metabolism. The conversion from tyrosine to 4-HPPA is catalyzed by tyrosine aminotransferase. Additionally, 4-HPPA can be converted to homogentisic acid which is one of the precursors to ochronotic pigment. The enzyme 4-hydroxyphenylpyruvic acid dioxygenase (HPD) catalyzes the reaction that converts 4-hydroxyphenylpyruvic acid to homogentisic acid. A deficiency in the catalytic activity of HPD is known to lead to tyrosinemia type III, an autosomal recessive disorder characterized by elevated levels of blood tyrosine and massive excretion of tyrosine derivatives into urine. It has been shown that hawkinsinuria, an autosomal dominant disorder characterized by the excretion of 'hawkinsin,' may also be a result of HPD deficiency (PMID: 11073718). Moreover, 4-hydroxyphenylpyruvic acid is also found to be associated in phenylketonuria, which is also an inborn error of metabolism. There are two isomers of HPPA, specifically 4HPPA and 3HPPA, of which 4HPPA is the most common. 4-HPPA has been found to be a microbial metabolite in Escherichia (ECMDB).
4-Methylcatechol, also known as homocatechol or toluene-3,4-diol, belongs to the class of organic compounds known as catechols. Catechols are compounds containing a 1,2-benzenediol moiety. Outside of the human body, 4-Methylcatechol is found, on average, in the highest concentration within a few different foods such as coffee and cocoa powders and in a lower concentration in beers. 4-Methylcatechol has also been detected, but not quantified in eggplants. This could make 4-methylcatechol a potential biomarker for the consumption of these foods. Recent studies have suggested that a lack of brain-derived neurotrophic factor (BDNF) in the limbic system may cause neuropathic pain (PMID:22198556). It is both a substrate and a suicide inhibitor of catechol 2,3-dioxygenase (PMID:15006807). 4-Methylcatechol is a metabolite of homoprotocatechuic acid (PMID:4974346). 4-Methylcatechol is known to induce the production of BDNF.
4-methylumbelliferone is a substrate for: Liver carboxylesterase 1, Cocaine esterase, and S-formylglutathione hydrolase.
4-Nitrocatechol is the by-product of the hydroxylation of 4-nitrophenol by the human cytochrome P450 (CYP) 2E1. This reaction is a useful metabolic marker for the presence of functional cytochrome P450 2E1 in mammalian cell microsomes. Hepatic and extrahepatic microsomal cytochrome P450 isozymes further catalyze the reduction of p-nitrocatechol into p-aminophenol (PMID: 8267647, 8214571, 8267647).
4-Pyridoxic acid is a member of the class of compounds known as methylpyridines. More specifically it is a 2-methylpyridine derivative substituted by a hydroxy group at C-3, a carboxy group at C-4, and a hydroxymethyl group at C-5. 4-Pyridoxic acid is the catabolic product of vitamin B6 (also known as pyridoxine, pyridoxal and pyradoxamine) and is excreted in the urine. Urinary levels of 4-pyridoxic acid are lower in females than in males and will be reduced even further in persons with a riboflavin deficiency. 4-Pyridoxic acid is formed by the action of aldehyde oxidase I (an endogenous enzyme) and by microbial enzymes (pyridoxal 4-dehydrogenase), an NAD-dependent aldehyde dehydrogenase. 4-pyridoxic acid can be further broken down by the gut microflora via the enzyme known as 4-pyridoxic acid dehydrogenase. This enzyme catalyzes the four-electron oxidation of 4-pyridoxic acid to 3-hydroxy-2-methylpyridine-4,5-dicarboxylate, using nicotinamide adenine dinucleotide (NAD) as a cofactor.
5'-Methylthioadenosine, also known as MTA or thiomethyladenosine, belongs to the class of organic compounds known as 5'-deoxy-5'-thionucleosides. These are 5'-deoxyribonucleosides in which the ribose is thio-substituted at the 5'position by a S-alkyl group. 5'-Methylthioadenosine is metabolized solely by MTA-phosphorylase, to yield 5-methylthioribose-1-phosphate and adenine, a crucial step in the methionine and purine salvage pathways, respectively. 5'-Methylthioadenosine exists in all living species, ranging from bacteria to humans. 5'-Methylthioadenosine (MTA) is a naturally occurring sulfur-containing nucleoside present in all mammalian tissues. Within humans, 5'-methylthioadenosine participates in a number of enzymatic reactions. In particular, 5'-methylthioadenosine and spermidine can be biosynthesized from S-adenosylmethioninamine and putrescine through the action of the enzyme spermidine synthase. In addition, 5'-methylthioadenosine can be converted into 5-methylthioribose 1-phosphate and L-methionine; which is catalyzed by the enzyme S-methyl-5'-thioadenosine phosphorylase. It is produced from S-adenosylmethionine mainly through the polyamine biosynthetic pathway, where it behaves as a powerful inhibitory product. For instance, 5'-Methylthioadenosine has been shown to influence the regulation of gene expression, proliferation, differentiation, and apoptosis (PMID:15313459). In humans, 5'-methylthioadenosine is involved in the metabolic disorder called hypermethioninemia. Outside of the human body, 5'-Methylthioadenosine has been detected, but not quantified in several different foods, such as soursops, allspices, summer grapes, alaska wild rhubarbs, and breadfruits. Elevated excretion appears in children with severe combined immunodeficiency syndrome (SCID) (PMID:3987052). Evidence suggests that 5'-Methylthioadenosine can affect cellular processes in many ways. 5'-Methylthioadenosine can be found in human urine.
Dimethylbenzimidazole is an intermediate in Riboflavin metabolism. Dimethylbenzimidazole is the second to last step for the synthesis of alpha-Ribazole. It is converted from Riboflavin then it is converted to N1-(5-Phospho-alpha-D-ribosyl)-5,6-dimethylbenzimidazole via the enzyme nicotinate-nucleotide--dimethylbenzimidazole phosphoribosyltransferase (EC 2.4.2.21).
5-Aminoimidazole-4-carboxamide is an imidazole derivative which is a metabolite of the antineoplastic agents BIC and DIC. By itself, or as the ribonucleotide, it is used as a condensation agent in the preparation of nucleosides and nucleotides. Compounded with orotic acid, it is used to treat liver diseases. -- Pubchem.
Mesalazine is only found in individuals that have used or taken this drug. It is an anti-inflammatory agent, structurally related to the salicylates, which is active in inflammatory bowel disease. It is considered to be the active moiety of sulphasalazine. (From Martindale, The Extra Pharmacopoeia, 30th ed)Although the mechanism of action of mesalazine is not fully understood, it appears to be topical rather than systemic. Mucosal production of arachidonic acid metabolites, both through the cyclooxygenase pathways, i.e., prostanoids, and through the lipoxygenase pathways, i.e., leukotrienes and hydroxyeicosatetraenoic acids, is increased in patients with chronic inflammatory bowel disease, and it is possible that mesalazine diminishes inflammation by blocking cyclooxygenase and inhibiting prostaglandin production in the colon.
5-Hydroxyindoleacetic acid, also known as 5-hydroxyindole-3-acetate or 5-HIAA, belongs to the class of organic compounds known as indole-3-acetic acid derivatives. Indole-3-acetic acid derivatives are compounds containing an acetic acid (or a derivative) linked to the C3 carbon atom of an indole. 5-Hydroxyindoleacetic acid exists in all living organisms, ranging from bacteria to humans. In humans, 5-hydroxyindoleacetic acid is a breakdown product of serotonin that is excreted in the urine and it also participates in a number of enzymatic reactions. 5-hydroxyindoleacetic acid can be biosynthesized from 5-hydroxyindoleacetaldehyde; which is catalyzed by the mitochondrial enzyme aldehyde dehydrogenase. In addition, 5-hydroxyindoleacetic acid and S-adenosylmethionine can be converted into 5-methoxyindoleacetate and S-adenosylhomocysteine through its interaction with the enzyme acetylserotonin O-methyltransferase. 5-Hydroxyindoleacetic acid is also involved in the metabolism of tryptophan. 5-Hydroxyindoleacetic acid has been found to be associated with several human diseases such as brunner syndrome, friedreich's ataxia, schizophrenia, and olivopontocerebral atrophy; 5-hydroxyindoleacetic acid has also been linked to the inborn metabolic disorder sepiapterin reductase deficiency. Elevated levels of 5-hydroxyindoleacetic acid in urine (>20 uM) are indicative of appendicitis and gastroenteritis (PMID: 11462886). Serotonin and 5-Hydroxyindoleacetic acid are produced in excess amounts by carcinoid tumors, and levels of these substances may be measured in the urine to test for carcinoid tumors (NCI). 5-Hydroxyindoleacetic acid has also been found to be a product of human gut microbiota.
5-Keto-D-gluconate is metabolized from glucose in certain bacterial species. It is an intermediate in L-idonate degradation and ketogluconate metabolism. 5-Keto-D-gluconate 5-reductase catalyzes the reversible reduction of 5-ketogluconate to D-gluconate. This is the second reaction of the L-idonate catabolic pathway after uptake of L-idonate into the cell. The enzyme specifically reduces 5-ketogluconate using either NADH or NADPH. The enzyme is also specific for D-gluconate oxidation using NADP as the coenzyme, NAD does not serve as a coenzyme. 5-Keto-D-gluconate has also been found to be a metabolite of Gluconobacter (https://www.sciencedirect.com/science/article/pii/S138111779800112X).
5-Methoxyindoleacetate, also known as 5-methoxy-IAA or 5-MIAA, belongs to the class of organic compounds known as indole-3-acetic acid derivatives. Indole-3-acetic acid derivatives are compounds containing an acetic acid (or a derivative) linked to the C3 carbon atom of an indole. 5-Methoxyindoleacetic acid is formed through oxidative deamination. It is identified in the urine, and the concentration is determined to be 1.3 µg/mL using GC-MS (PMID: 12908946). An increase in urinary 5-MIAA excretion was shown in patients with cancer of the stomach, rectum, and lung (PMID: 2446428).
Bergapten, also known as O-methylbergaptol or heraclin, belongs to the class of organic compounds known as 5-methoxypsoralens. These are psoralens containing a methoxy group attached at the C5 position of the psoralen group. Bergapten is found, on average, in the highest concentration within a few different foods, such as anises, figs, and parsnips and in a lower concentration in carrots, fennels, and celery stalks. Bergapten has also been detected, but not quantified, in several different foods, such as coconuts, pepper (c. frutescens), corianders, sesbania flowers, and cardamoms. This could make bergapten a potential biomarker for the consumption of these foods. It is also found in rose hip, sweet marjoram, greenthread tea, and tartary buckwheat. Bergapten is a potentially toxic compound. Bergapten is a major constituent of bergamot oil (Citrus bergamia). Present in celery, especially the outer leaves, and other common grocery vegetables. Implicated in photodermatitis among grocery workers. Bergapten was under investigation in clinical trial NCT00533195 "Comparison of UVA1 Phototherapy Versus Photochemotherapy for Patients With Severe Generalized Atopic Dermatitis".
5-Methylcytidine belongs to the class of organic compounds known as pyrimidine nucleosides. Pyrimidine nucleosides are compounds comprising a pyrimidine base attached to a ribosyl or deoxyribosyl moiety.
Ribothymidine is an endogenous methylated nucleoside found in human fluids; methylated purine bases are present in higher amounts in tumor-bearing patients compared to healthy controls.DNA hypermethylation is a common finding in malignant cells and has been explored as a therapeutic target for hypomethylating agents. When chemical bonds to DNA, the DNA becomes damaged and proper and complete replication cannot occur to make the normal intended cell. A DNA adduct is an abnormal piece of DNA covalently-bonded to a cancer-causing chemical. This has shown to be the start of a cancerous cell, or carcinogenesis. DNA adducts in scientific experiments are used as bio-markers and as such are themselves measured to reflect quantitatively, for comparison, the amount of cancer in the subject. (PMID:3506820, 17044778, 17264127, 16799933).
Aesculetin, also known as cichorigenin or cichoriin aglucon, belongs to the class of organic compounds known as 6,7-dihydroxycoumarins. These are coumarins bearing two hydroxyl groups at positions 6 and 7 of the coumarin skeleton, respectively. Aesculetin is found, on average, in the highest concentration within sherries. Aesculetin has also been detected, but not quantified, in several different foods, such as horseradish, carrots, dandelions, grape wines, and highbush blueberries. This could make aesculetin a potential biomarker for the consumption of these foods.
6-Methylmercaptopurine is a metabolite of mercaptopurine. Mercaptopurine (also called 6-mercaptopurine, 6-MP or its brand name Purinethol) is an immunosuppressive drug. It is a thiopurine. (Wikipedia)
Acetaminophen glucuronide is a natural human metabolite of Acetaminophen generated in the liver by UDP glucuonyltransferase. Glucuronidation is used to assist in the excretion of toxic substances, drugs or other substances that cannot be used as an energy source. Glucuronic acid is attached via a glycosidic bond to the substance, and the resulting glucuronide, which has a much higher water solubility than the original substance, is eventually excreted by the kidneys. Acetaminophen glucuronide is found to be associated with beta-thalassemia, which is an inborn error of metabolism.
The excellent tolerability of therapeutic doses of paracetamol (acetaminophen) is a major factor in the very wide use of the drug. The major problem in the use of paracetamol is its hepatotoxicity after an overdose. Hepatotoxicity has also been reported after therapeutic doses, but critical analysis indicates that most patients with alleged toxicity from therapeutic doses have taken overdoses. Importantly, prospective studies indicate that therapeutic doses of paracetamol are an unlikely cause of hepatotoxicity in patients who ingest moderate to large amounts of alcohol (PMID: 15733027). Single doses of paracetamol are effective analgesics for acute postoperative pain and give rise to few adverse effects (PMID: 14974073). Acetaminophen (AAP) overdose and the resulting hepatotoxicity is an important clinical problem. In addition, AAP is widely used as a prototype hepatotoxin to study mechanisms of chemical-induced cell injury and to test the hepatoprotective potential of new drugs and herbal medicines. Because of its importance, the mechanisms of AAP-induced liver cell injury have been extensively investigated and controversially discussed for many years (PMID: 16863451).
Adenine is a purine base. Adenine is found in both DNA and RNA. Adenine is a fundamental component of adenine nucleotides. Adenine forms adenosine, a nucleoside, when attached to ribose, and deoxyadenosine when attached to deoxyribose; it forms adenosine triphosphate (ATP), a nucleotide, when three phosphate groups are added to adenosine. Adenosine triphosphate is used in cellular metabolism as one of the basic methods of transferring chemical energy between chemical reactions. Purine inborn errors of metabolism (IEM) are serious hereditary disorders, which should be suspected in any case of neonatal fitting, failure to thrive, recurrent infections, neurological deficit, renal disease, self-mutilation and other manifestations. Investigation usually starts with uric acid (UA) determination in urine and plasma. (OMIM 300322, 229600, 603027, 232400, 232600, 232800, 201450, 220150, 232200, 162000, 164050, 278300). (PMID: 17052198, 17520339).
Cyclic AMP (cAMP) or cyclic adenosine monophosphate is an adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. cAMP is found in all organisms ranging from bacteria to plants to animals. In humans and other mammals it is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon and ACTH. cAMP is synthesized from ATP by adenylate cyclase. Adenylate cyclase is located at the inner side of cell membranes. Adenylate cyclase is activated by the hormones glucagon and adrenaline and by G protein. Liver adenylate cyclase responds more strongly to glucagon, and muscle adenylate cyclase responds more strongly to adrenaline. cAMP decomposition into AMP is catalyzed by the enzyme phosphodiesterase. cAMP is primarily used for intracellular signal transduction, such as transferring into cells the effects of hormones like glucagon and adrenaline, which cannot pass through the plasma membrane. cAMP is also involved in the activation of protein kinases. In addition, cAMP binds to and regulates the function of ion channels such as the HCN channels. Hyperpolarization-activated cyclic nucleotide‚Äìgated (HCN) channels are integral membrane proteins that serve as nonselective voltage-gated cation channels in the plasma membranes of heart and brain cells. HCN channels are sometimes referred to as pacemaker channels because they help to generate rhythmic activity within groups of heart and brain cells.
Adenylic acid. Adenine nucleotide containing one phosphate group esterified to the sugar moiety in the 2'-, 3'-, or 5'-position. 3'-AMP has been identified in the human placenta (PMID: 32033212).
Adenosine is a nucleoside that is composed of adenine and D-ribose. Adenosine or adenosine derivatives play many important biological roles in addition to being components of DNA and RNA. For instance, adenosine plays an important role in energy transfer as adenosine triphosphate (ATP) and adenosine diphosphate (ADP). It also plays a role in signal transduction as cyclic adenosine monophosphate (cAMP). Adenosine itself is both a neurotransmitter and potent vasodilator. When administered intravenously adenosine causes transient heart block in the AV node. Due to the effects of adenosine on AV node-dependent supraventricular tachycardia, adenosine is considered a class V antiarrhythmic agent. Overdoses of adenosine intake (as a drug) can lead to several side effects including chest pain, feeling faint, shortness of breath, and tingling of the senses. Serious side effects include a worsening dysrhythmia and low blood pressure. When present in sufficiently high levels, adenosine can act as an immunotoxin and a metabotoxin. An immunotoxin disrupts, limits the function, or destroys immune cells. A metabotoxin is an endogenous metabolite that causes adverse health effects at chronically high levels. Chronically high levels of adenosine are associated with adenosine deaminase deficiency. Adenosine is a precursor to deoxyadenosine, which is a precursor to dATP. A buildup of dATP in cells inhibits ribonucleotide reductase and prevents DNA synthesis, so cells are unable to divide. Since developing T cells and B cells are some of the most mitotically active cells, they are unable to divide and propagate to respond to immune challenges. High levels of deoxyadenosine also lead to an increase in S-adenosylhomocysteine, which is toxic to immature lymphocytes.
Adipic acid is an important inudstrial dicarboxylic acid with about 2.5 billion kilograms produced per year. It is used mainly in the production of nylon. It occurs relatively rarely in nature. It has a tart taste and is also used as an additive and gelling agent in jello or gelatins. It is also used in some calcium carbonate antacids to make them tart. Adipic acid has also been incorporated into controlled-release formulation matrix tablets to obtain pH-independent release for both weakly basic and weakly acidic drugs. Adipic acid in the urine and in the blood is typically exogenous in origin and is a good biomarker of jello consumption. In fact, a condition known as adipic aciduria is actually an artifact of jello consumption (PMID: 1779643). However, certain disorders (such as diabetes and glutaric aciduria type I.) can lead to elevated levels of adipic acid snd other dicarboxcylic acids (such as suberic acid) in urine (PMID: 17520433; PMID: 6778884). Moreover, adipic acid is also found to be associated with 3-hydroxy-3-methylglutaryl-CoA lyase deficiency, carnitine-acylcarnitine translocase deficiency, malonyl-Coa decarboxylase deficiency, and medium Chain acyl-CoA dehydrogenase deficiency, which are inborn errors of metabolism. Adipic acid is also microbial metabolite found in Escherichia.
The ATP-dependent carboxylate-amine/thiol ligase superfamily is known to contain enzymes catalyzing the formation of various types of peptide, one of which is d-alanyl-d-alanine.(PMID: 16030213). The glycopeptide antibiotic vancomycin acts by binding to the D-alanyl-D-alanine terminus of the cell wall precursor lipid II in the cytoplasmic membrane.(PMID: 17418637). D-alanine-D-alanine ligase from Thermotoga maritima ATCC 43589 (TmDdl) was a useful biocatalyst for synthesizing D-amino acid dipeptides.D-Alanine-D-alanine ligase (Ddl) catalyzes the biosynthesis of an essential bacterial peptidoglycan precursor D-alanyl-D-alanine and it represents an important target for development of new antibacterial drugs. (PMID: 17267218). D-Alanyl-D-alanine is a microbial metabolite.
Alanylisoleucine is a dipeptide composed of alanine and isoleucine. It is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis.
Alanylvaline is a dipeptide composed of alanine and valine. It is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis.
Albendazole is only found in individuals that have used or taken this drug. It is a benzimidazole broad-spectrum anthelmintic structurally related to mebendazole that is effective against many diseases. (From Martindale, The Extra Pharmacopoeia, 30th ed, p38)Albendazole causes degenerative alterations in the tegument and intestinal cells of the worm by binding to the colchicine-sensitive site of tubulin, thus inhibiting its polymerization or assembly into microtubules. The loss of the cytoplasmic microtubules leads to impaired uptake of glucose by the larval and adult stages of the susceptible parasites, and depletes their glycogen stores. Degenerative changes in the endoplasmic reticulum, the mitochondria of the germinal layer, and the subsequent release of lysosomes result in decreased production of adenosine triphosphate (ATP), which is the energy required for the survival of the helminth. Due to diminished energy production, the parasite is immobilized and eventually dies.
Alfuzosin is only found in individuals that have used or taken this drug. It is an alpha-adrenergic blocker used to treat benign prostatic hyperplasia (BPH). It works by relaxing the muscles in the prostate and bladder neck, making it easier to urinate. [Wikipedia]Alfuzosin is a non-subtype specific alpha(1)-adrenergic blocking agent that exhibits selectivity for alpha(1)-adrenergic receptors in the lower urinary tract. Inhibition of these adrenoreceptors leads to the relaxation of smooth muscle in the bladder neck and prostate, resulting in the improvement in urine flow and a reduction in symptoms in benign prostate hyperplasia. Alfuzosin also inhibits the vasoconstrictor effect of circulating and locally released catecholamines (epinephrine and norepinephrine), resulting in peripheral vasodilation.
Allantoin is a diureide of glyoxylic acid with the chemical formula C4H6N4O3. It is also called 5-ureidohydantoin or glyoxyldiureide. It is a product of the oxidation of uric acid. It is also a product of purine metabolism in most mammals except for higher apes, and it is present in their urine. In humans, uric acid is excreted instead of allantoin. The presence of allantoin in the urine can be an indication of microbial overgrowth or it can be created via non-enzymatic means through high levels of reactive oxygen species. In this regard, allantoin is sometimes used as a marker of oxidative stress. Allantoin can be isolated from cow urine or as a botanical extract of the comfrey plant. It has long been used for its healing, soothing, and anti-irritating properties. Allantoin helps to heal wounds and skin irritations and stimulates the growth of healthy tissue. Allantoin can be found in anti-acne products, sun care products, and clarifying lotions because of its ability to help heal minor wounds and promote healthy skin. Allantoin is frequently present in toothpaste, mouthwash, and other oral hygiene products as well as in shampoos, lipsticks, various cosmetic lotions and creams, and other cosmetic and pharmaceutical products. It is also a metabolite of Bacillus (PMID: 18302748) and Streptomyces (PMID: 24292080).
Alpha-Hydroxyhippuric acid, also known as alpha-hydroxybenzoylglycine or a-hydroxyhippate, belongs to the class of organic compounds known as hippuric acids. Hippuric acids are compounds containing hippuric acid, which consists of a of a benzoyl group linked to the N-terminal of a glycine. Alpha-Hydroxyhippuric acid (or Benzamidohydroxyacetic acid) is a carboxylic acid occasionally present in human biofluids. Alpha-hydroxyhippuric acid should not be confused with 2-hydroxyhippuric acid. It is used in the formulation of some herbicides and inks to enhance their action (Patents US 1996-657134, US 1975-627965). It is a substrate for the enzyme peptidyl-alpha-hydroxyglycine alpha-amidating lyase. Alpha-Hydroxyhippuric acid (or Benzamidohydroxyacetic acid) is a hippuric acid derivative that is occasionally present in human biofluids.
2-oxo-4-methylthiobutanoate, also known as 2-keto-4-methylthiobutyric acid, 2-keto-4-methylthiobutyrate or 4-(methylsulfanyl)-2-oxobutanoic acid, is a member of the class of compounds known as thia- fatty acids. Thia-fatty acids are fatty acid derivatives obtained by insertion of a sulfur atom at specific positions in the chain. Thus, 2-oxo-4-methylthiobutanoate is a fatty acid lipid molecule. 2-oxo-4-methylthiobutanoate is slightly soluble (in water) and a weakly acidic compound (based on its pKa). 2-oxo-4-methylthiobutanoate can be synthesized from L-methionine and butyric acid. 2-oxo-4-methylthiobutanoate can also be synthesized into S-adenosyl-4-methylthio-2-oxobutanoic acid. 2-oxo-4-methylthiobutanoate can be found in a number of food items such as cloves, highbush blueberries, common beets, and cashew nuts. 2-oxo-4-methylthiobutanoate can be found in urine. Within the cell, 2-oxo-4-methylthiobutanoate is primarily located in the cytoplasm and in the membrane. 2-oxo-4-methylthiobutanoate has been found in all living species, from bacteria to humans. In humans, 2-oxo-4-methylthiobutanoate is found to be involved in several metabolic disorders, some of those are S-adenosylhomocysteine (SAH) hydrolase deficiency, methylenetetrahydrofolate reductase deficiency (MTHFRD), methionine adenosyltransferase deficiency, and glycine N-methyltransferase deficiency. 4-Methylthio-2-oxobutanoic acid is the direct precursor of methional, which is a potent inducer of apoptosis in a BAF3 murine lymphoid cell line which is interleukin-3 (IL3)-dependent (PMID: 7848263).
A pyrazine compound inhibiting sodium reabsorption through sodium channels in renal epithelial cells. This inhibition creates a negative potential in the luminal membranes of principal cells, located in the distal convoluted tubule and collecting duct. Negative potential reduces secretion of potassium and hydrogen ions. Amiloride is used in conjunction with diuretics to spare potassium loss. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p705)
Amisulpride (trade name Solian) is an antipsychotic drug sold by Sanofi-Aventis. It is not approved for use in the United States, but is approved for use in Europe and Australia for the treatment of psychoses and schizophrenia. Additionally, it is approved in Italy for the treatment of dysthymia (under the brand name Deniban). Amisulpride is a selective dopamine antagonist.
Amlexanox is an antiallergic drug, clinically effective for atopic diseases, especially allergic asthma and rhinitis. Amlexanox as a topical paste is a well tolerated treatment of recurrent aphthous ulcers. Recurrent aphthous ulcer (RAU) is the most prevalent oral mucosal disease in humans, estimated to affect between 5% and 50% of the general population.
Amlodipine is a long-acting calcium channel blocker used as an anti-hypertensive and in the treatment of angina. As other calcium channel blockers, amlodipine acts by relaxing the smooth muscle in the arterial wall, decreasing peripheral resistance and hence improving blood pressure; in angina it improves blood flow to the myocardium. It was developed under the direction of Dr. Simon Campbell; A long acting dihydropyridine calcium channel blocker. It is effective in the treatment of angina pectoris and hypertension; in angina it improves blood flow to the myocardium. Amlodipine (as besylate, mesylate or maleate) is a long-acting calcium channel blocker used as an anti hypertensive and in the treatment of angina. Amlodipine is marketed as Norvasc in North America and as Istin in the United Kingdom as well as under various other names. As other calcium channel blockers, amlodipine acts by relaxing the smooth muscle in the arterial wall, decreasing peripheral resistance and hence improving blood pressure; Amlodipine (as besylate, mesylate or maleate) is a long-acting calcium channel blocker used as an anti-hypertensive and in the treatment of angina. Amlodipine is marketed as Norvasc in North America and as Istin in the United Kingdom as well as under various other names. As other calcium channel blockers, amlodipine acts by relaxing the smooth muscle in the arterial wall, decreasing peripheral resistance and hence improving blood pressure; in angina it improves blood flow to the myocardium. It was developed under the direction of Dr. Simon Campbell.
Anagrelide is only found in individuals that have used or taken this drug. It is a drug used for the treatment of essential thrombocytosis (ET; essential thrombocythemia). It also has been used in the treatment of chronic myeloid leukemia. [Wikipedia]The mechanism by which anagrelide reduces blood platelet count is still under investigation. Studies in patients support a hypothesis of dose-related reduction in platelet production resulting from a decrease in megakaryocyte hypermaturation. In blood withdrawn from normal volunteers treated with anagrelide, a disruption was found in the postmitotic phase of megakaryocyte development and a reduction in megakaryocyte size and ploidy. At therapeutic doses, anagrelide does not produce significant changes in white cell counts or coagulation parameters, and may have a small, but clinically insignificant effect on red cell parameters. Anagrelide inhibits cyclic AMP phosphodiesterase III (PDEIII). PDEIII inhibitors can also inhibit platelet aggregation. However, significant inhibition of platelet aggregation is observed only at doses of anagrelide higher than those required to reduce platelet count.
Aprobarbital is a barbiturate derivative synthesized in the 1920s by Ernst Preiswerk. It has sedative, hypnotic and anticonvulsant properties, and was used primarily for the treatment of insomnia. Aprobarbital was never as widely used as more common barbiturate derivatives such as phenobarbital and is now rarely prescribed.
D-Arabitol is a polyol. Polyols are sugar alcohols linked to the pentose phosphate pathway (PPP). They are classified on the basis of the number of carbon atoms. Polyols occur in body fluids. A patient with leukoencephalopathy and peripheral neuropathy has been identified as suffering from ribose-5-phosphate isomerase (RPI) deficiency, a defect in the PPP. In this disorder, highly elevated concentrations of the C5 polyols such as D-arabitol are found in body fluids. In addition, transaldolase deficiency, another defect in the PPP, has been diagnosed in a patient with mainly liver problems among others. This patient had increased concentrations of polyols, mainly D-arabitol. So far, the pathophysiological role of polyols is relatively unknown. It is thought that D-arabitol is a metabolic end-product in humans. The strong brain-CSF-plasma gradient of polyols in the patient with RPI deficiency suggested a primary metabolic disorder. The mechanisms of brain and neuronal damage in RPI deficiency remain to be elucidated. A neurotoxic effect due to the accumulation of the polyols may play a role. D-Arabitol is a product of the enzyme D-arabinitol 4-dehydrogenase (EC 1.1.1.11) in the pentose and glucuronate interconversion pathway (PMID: 16435225, J Inherit Metab Dis. 2005;28(6):1181-3). D-Arabitol has also been found to be a fungal metabolite, urinary D-Arabinitol is a marker for invasive candidiasis or infection by Candida fungal species (PMID: 15183861; PMID: 10647119). It can also a metabolite in Debaryomyces, Pichia and Zygosaccharomyces (PMID: 25809659).
Arachidic acid, also known as icosanoic acid, is a saturated fatty acid with a 20-carbon chain. It is a minor constituent of butter, perilla oil, peanut oil, corn oil, and cocoa butter. It also constitutes 7.08% of the fats from the fruit of the durian species Durio graveolens. The salts and esters of arachidic acid are known as arachidates. Its name derives from the Latin arachis that means peanut. It can be formed by the hydrogenation of arachidonic acid. The reduction of arachidic acid yields arachidyl alcohol. Arachidic acid is used for the production of detergents, photographic materials and lubricants. Arachidic acid belongs to the class of organic compounds known as long-chain fatty acids. These are fatty acids with an aliphatic tail that contains between 13 and 21 carbon atoms. Arachidic acid is a very hydrophobic molecule, practically insoluble in water, and relatively neutral.
Arbutin is found in apple. Glucoside in pear leaves (Pyrus communis
Aripiprazole is a warning has gone out recently because of this drug's name. The '-prazole' ending of this drug name makes this drug sound like it is one of the proton pump inhibitors (such as omeprazole, pantoprazole, lansoprazole) which are used in treating peptic ulcer disease. However, aripiprazole and these drugs are in an entirely different class of drugs altogether and confusing the two can lead to some unnecessary side effects. Aripiprazole is the sixth and most recent of the atypical antipsychotic medications to be approved by the Food and Drug Administration (FDA) for the treatment of schizophrenia. It has also recently received FDA approval for the treatment of acute manic and mixed episodes associated with bipolar disorder. Aripiprazole appears to mediate its antipsychotic effects primarily by partial agonism at the Dopamine 2 (D2)receptor.
Ascorbic acid is found naturally in citrus fruits and many vegetables and is an essential nutrient in human diets. It is necessary to maintain connective tissue and bone. The biologically active form of ascorbic acid is vitamin C. Vitamin C is a water soluble vitamin. Primates (including humans) and a few other species in all divisions of the animal kingdom, notably the guinea pig, have lost the ability to synthesize ascorbic acid and must obtain it in their food. Vitamin C functions as a reducing agent and coenzyme in several metabolic pathways. Vitamin C is considered an antioxidant (PubChem). Ascorbic acid is an electron donor for enzymes involved in collagen hydroxylation, biosynthesis of carnitine and norepinephrine, tyrosine metabolism, and amidation of peptide hormones. Ascrobic acid (vitamin C) deficiency causes scurvy. The amount of vitamin C necessary to prevent scurvy may not be adequate to maintain optimal health. The ability of vitamin C to donate electrons also makes it a potent water-soluble antioxidant that readily scavenges free radicals such as molecular oxygen, superoxide, hydroxyl radical, and hypochlorous acid. In this setting, several mechanisms could account for a link between vitamin C and heart disease. One is the relation between LDL oxidation and vitamins C and E. Vitamin C in vitro can recycle vitamin E, which can donate electrons to prevent LDL oxidation in vitro. As the lipid-phase vitamin E is oxidized, it can be regenerated by aqueous vitamin C. Other possibilities are that vitamin C could decrease cholesterol by mechanisms not well characterized, or could improve vasodilatation and vascular reactivity, perhaps by decreasing the interactions of nitric oxide with oxidants (PMID: 10799361). Moreover, ascorbic acid is found to be associated with hyperoxalemia, which is an inborn error of metabolism. Ascorbic acid is also a microbial metabolite produced by Ketogulonicigenium (PMID: 15785002).
Aspartylphenylalanine is a dipeptide composed of aspartate and phenylalanine, and is a metabolic byproduct of its methyl ester, aspartame (Nutrasweet). After hydrolysis of the ester bond in the intestinal lumen, the dipeptide is apparently absorbed and digested in the same manner as dipeptides derived from protein digestion. There are several Asp-Phe dipeptidases that degrade this peptide. It has been suggested that individuals with aspartame allergies may be deficient in this peptidase (PMID: 3743970). It has been observed that N-beta-aspartylphenylalanine (a breakdown product of Asp-Phe) is a naturally occurring peptide found in both blood and urine (PMID: 2723819).
Benazepril, brand name Lotensin, is a medication used to treat high blood pressure (hypertension), congestive heart failure, and chronic renal failure. Upon cleavage of its ester group by the liver, benazepril is converted into its active form benazeprilat, a non-sulfhydryl angiotensin-converting enzyme (ACE) inhibitor.
Benzbromarone (INN) is a uricosuric agent used in the treatment of gout, especially when allopurinol, a first-line treatment, fails or produces intolerable adverse effects. It is structurally related to the antiarrhythmic amiodarone. Benzbromarone is a very potent inhibitor of CYP2C9. Several analogues of the drug have been developed as CYP2C9 and CYP2C19 inhibitors for use in research.
Benzoic acid, C6H5COOH, is a colourless crystalline solid and the simplest aromatic carboxylic acid. Benzoic acid occurs naturally free and bound as benzoic acid esters in many plant and animal species. Appreciable amounts have been found in most berries (around 0.05%). Cranberries contain as much as 300-1300 mg free benzoic acid per kg fruit. Benzoic acid is a fungistatic compound that is widely used as a food preservative. It often is conjugated to glycine in the liver and excreted as hippuric acid. Benzoic acid is a byproduct of phenylalanine metabolism in bacteria. It is also produced when gut bacteria process polyphenols (from ingested fruits or beverages). It can be found in Serratia (PMID:23061754).
Benzyl acetate, also known as benzyl ethanoate or fema 2135, belongs to the class of organic compounds known as benzyloxycarbonyls. These are organic compounds containing a carbonyl group substituted with a benzyloxyl group. Benzyl acetate is a sweet, apple, and apricot tasting compound. Benzyl acetate is found, on average, in the highest concentration within sweet basils. Benzyl acetate has also been detected, but not quantified, in several different foods, such as figs, fruits, pomes, tea, and alcoholic beverages. On high concnetrations benzyl acetate is a potentially toxic compound. If the compound has entered the eyes, they should be washed with large quantities of isotonic saline or water.
L-3-Cyanoalanine, also known as L-beta-cyanoalanine, belongs to the class of organic compounds known as L-alpha-amino acids. These are alpha-amino acids which have the L-configuration of the alpha-carbon atom. L-3-Cyanoalanine is a very strong basic compound (based on its pKa). L-3-Cyanoalanine exists in all living organisms, ranging from bacteria to humans. Outside of the human body, L-3-cyanoalanine has been detected, but not quantified in, several different foods, such as summer savouries, orange bell peppers, red rices, mixed nuts, and green bell peppers. This could make L-3-cyanoalanine a potential biomarker for the consumption of these foods.
Bicalutamide is only found in individuals that have used or taken this drug. It is an oral non-steroidal anti-androgen for prostate cancer. It binds to the androgen receptor.Bicalutamide competes with androgen for the binding of androgen receptors, consequently blocking the action of androgens of adrenal and testicular origin which stimulate the growth of normal and malignant prostatic tissue.
Bupropion is a selective catecholamine (norepinephrine and dopamine) reuptake inhibitor. It has only a small effect on serotonin reuptake. It does not inhibit MAO. The antidepressant effect of bupropion is considered to be mediated by its dopaminergic and noradrenergic action. Bupropion has also been shown to act as a competitive alpha-3-beta-4- nicotinic antagonist, the alpha-3-beta-4-antagonism has been shown to interrupt addiction in studies of other drugs such as ibogaine. This alpha-3-beta-4-antagonism correlates quite well with the observed effect of interrupting addiction. A unicyclic, aminoketone antidepressant. The mechanism of its therapeutic actions is not well understood, but it does appear to block dopamine uptake. The hydrochloride is available as an aid to smoking cessation treatment; Bupropion is a selective catecholamine (norepinephrine and dopamine) reuptake inhibitor. It has only a small effect on serotonin reuptake. It does not inhibit MAO. The antidepressant effect of bupropion is considered to be mediated by its dopaminergic and noradrenergic action. Bupropion has also been shown to act as a competitive alpha-3-beta-4-nicotinic antagonist, the alpha-3-beta-4-antagonism has been shown to interrupt addiction in studies of other drugs such as ibogaine. This alpha-3-beta-4-antagonism correlates quite well with the observed effect of interrupting addiction. Bupropion (amfebutamone) (brand names Wellbutrin and Zyban) is an antidepressant of the aminoketone class, chemically unrelated to tricyclics or selective serotonin reuptake inhibitors (SSRIs). It is similar in structure to the stimulant cathinone, and to phenethylamines in general. It is a chemical derivative of diethylpropion, an amphetamine-like substance used as an anorectic. Bupropion is both a dopamine reuptake inhibitor and a norepinephrine reuptake inhibitor. It is often used as a smoking cessation aid.
Butalbital, 5-allyl-5-isobutylbarbituric acid, is a barbiturate with an intermediate duration of action. It has the same chemical formula as talbutal but a different structure. Butalbital is often combined with other medications, such as acetaminophen or aspirin, and is commonly prescribed for the treatment of pain and headache. [Wikipedia]
Caffeic acid (CAS: 331-39-5) is a polyphenol present in normal human urine positively correlated to coffee consumption and influenced by the dietary intake of diverse types of food (PMID:16870009). Caffeic acid has been found to be a microbial metabolite of Escherichia (PMID: 28396925).
Phenylglyoxylic acid is one of the major urinary metabolites of toluene, o-, m- and p-xylenes, styrene and ethylbenzene. (PMID 3782394). For the biological monitoring of workers exposure to solvent used in industry, its concentration is measured in human urine samples. (PMID 2739101).
Carboxy-ibuprofen is a metabolite of ibuprofen. Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) used for relief of symptoms of arthritis, fever, as an analgesic (pain reliever), especially where there is an inflammatory component, and dysmenorrhea. Ibuprofen is known to have an antiplatelet effect, though it is relatively mild and somewhat short-lived when compared with aspirin or other better-known antiplatelet drugs. (Wikipedia)
Carvedilol is only found in individuals that have used or taken this drug. It is a non-selective beta blocker indicated in the treatment of mild to moderate congestive heart failure (CHF).Carvedilol is a racemic mixture in which nonselective beta-adrenoreceptor blocking activity is present in the S(-) enantiomer and alpha-adrenergic blocking activity is present in both R(+) and S(-) enantiomers at equal potency. Carvedilol's beta-adrenergic receptor blocking ability decreases the heart rate, myocardial contractility, and myocardial oxygen demand. Carvedilol also decreases systemic vascular resistance via its alpha adrenergic receptor blocking properties. Carvedilol and its metabolite BM-910228 (a less potent beta blocker, but more potent antioxidant) have been shown to restore the inotropic responsiveness to Ca<sup>2+</sup> in OH<sup>-</sup> free radical-treated myocardium. Carvedilol and its metabolites also prevent OH<sup>-</sup> radical-induced decrease in sarcoplasmic reticulum Ca<sup>2+</sup>-ATPase activity. Therefore, carvedilol and its metabolites may be beneficial in chronic heart failure by preventing free radical damage.
Catechin, also known as cyanidanol or catechuic acid, belongs to the class of organic compounds known as catechins. Catechins are compounds containing a catechin moiety, which is a 3,4-dihydro-2-chromene-3,5.7-tiol. Catechin also belongs to the group of compounds known as flavan-3-ols (or simply flavanols), part of the chemical family of flavonoids. Catechin is one of the 4 catechin known diastereoisomers. Two of the isomers are in trans configuration and are called catechin and the other two are in cis configuration and are called epicatechin. The most common catechin isomer is the (+)-catechin. The other stereoisomer is (-)-catechin or ent-catechin. The most common epicatechin isomer is (-)-epicatechin. Catechin is a very hydrophobic molecule, practically insoluble (in water), and relatively neutral. Catechin is a bitter tasting compound and is associated with the bitterness in tea. Catechin is a plant secondary metabolite. Secondary metabolites are metabolically or physiologically non-essential metabolites that may serve a role as defense or signalling molecules. In some cases they are simply molecules that arise from the incomplete metabolism of other secondary metabolites. Catechin is an antioxidant flavonoid, occurring especially in woody plants as both Catechin and (-)-Catechin (cis) forms. Outside of the human body, Catechin is found, on average, in the highest concentration in foods, such as blackcurrants (Ribes nigrum), evergreen blackberries (Rubus laciniatus), and blackberries (Rubus) and in a lower concentration in dills (Anethum graveolens), hot chocolates, and medlars (Mespilus germanica). Catechin has also been detected, but not quantified in, several different foods, such as rice (Oryza sativa), apple ciders, peanuts (Arachis hypogaea), fruit juices, and red teas. This could make catechin a potential biomarker for the consumption of these foods. Based on a literature review a significant number of articles have been published on Catechin.
Cefdinir (marketed by Abbott Laboratories under the brand name Omnicef) is a semi-synthetic, broad-spectrum antibiotic in the third generation of the cephalosporin class, proven effective for common bacterial infections of the ear, sinus, throat, and skin. It was approved by the U.S. Food and Drug Administration (FDA) in December of 1997.
Cefixime, an antibiotic, is a third-generation cephalosporin like ceftriaxone and cefotaxime. Cefixime is highly stable in the presence of beta-lactamase enzymes. As a result, many organisms resistant to penicillins and some cephalosporins due to the presence of beta-lactamases, may be susceptible to cefixime. The antibacterial effect of cefixime results from inhibition of mucopeptide synthesis in the bacterial cell wall.
A renal dehydropeptidase-I and leukotriene D4 dipeptidase inhibitor. Since the antibiotic, imipenem, is hydrolyzed by dehydropeptidase-I, which resides in the brush border of the renal tubule, cilastatin is administered with imipenem to increase its effectiveness. The drug also inhibits the metabolism of leukotriene D4 to leukotriene E4. [PubChem]
trans-Cinnamic acid, also known as (e)-cinnamic acid or phenylacrylic acid, belongs to the class of organic compounds known as cinnamic acids. These are organic aromatic compounds containing a benzene and a carboxylic acid group forming 3-phenylprop-2-enoic acid. trans-Cinnamic acid exists in all living species, ranging from bacteria to humans. trans-Cinnamic acid is a sweet, balsam, and cinnamon tasting compound. Outside of the human body, trans-Cinnamic acid is found, on average, in the highest concentration within a few different foods, such as chinese cinnamons, olives, and lingonberries and in a lower concentration in redcurrants, red raspberries, and corianders. trans-Cinnamic acid has also been detected, but not quantified in several different foods, such as common oregano, pepper (spice), fennels, pomegranates, and european cranberries. This could make trans-cinnamic acid a potential biomarker for the consumption of these foods. Cinnamic acid has been shown to be a microbial metabolite; it can be found in Alcaligenes, Brevibacterium, Cellulomonas, and Pseudomonas (PMID:16349793). trans-Cinnamic acid is a potentially toxic compound.
Citraconic acid, also known as 2-methylmaleate or methylmaleic acid, belongs to the class of organic compounds known as methyl-branched fatty acids. These are fatty acids with an acyl chain that has a methyl branch. Usually, they are saturated and contain only one or more methyl group. However, branches other than methyl may be present. Citraconic acid is a dicarboxylic acid consisting of maleic acid having a methyl substituent at the 2-position. Citraconic acid exists as a white solid. It is the cis-isomer of mesaconic acid and is one of the pyrocitric acids formed upon the heating of citric acid.  Citraconic acid has been detected in the urine of both normal and fasting individuals (PMID: 6778884). Citraconic acid is also elevated in the urine of individuals with methylmalonic acidaemia who have suffered ketotic attacks (PMID: 116077).  Altered serum levels of citraconic acid have been detected in patients with primary biliary cholangitis (PMID: 28400566).
Cladribine is only found in individuals that have used or taken this drug. It is an antineoplastic agent used in the treatment of lymphoproliferative diseases including hairy-cell leukemia. [PubChem]Cladribine is structurally related to fludarabine and pentostatin but has a different mechanism of action. Although the exact mechanism of action has not been fully determined, evidence shows that cladribine is phosphorylated by deoxycytidine kinase to the nucleotidecladribine triphosphate (CdATP; 2-chloro-2â€²-deoxyadenosine 5â€²-triphosphate), which accumulates and is incorporated into DNA in cells such as lymphocytes that contain high levels of deoxycytidine kinase and low levels of deoxynucleotidase, resulting in DNA strand breakage and inhibition of DNA synthesis and repair. High levels of CdATP also appear to inhibit ribonucleotide reductase, which leads to an imbalance in triphosphorylated deoxynucleotide (dNTP) pools and subsequent DNA strand breaks, inhibition of DNA synthesis and repair, nicotinamide adenine dinucleotide (NAD) and ATP depletion, and cell death. Unlike other antimetabolite drugs, cladribine has cytotoxic effects on resting as well as proliferating lymphocytes. However, it does cause cells to accumulate at the G1/S phase junction, suggesting that cytotoxicity is associated with events critical to cell entry into S phase. It also binds purine nucleoside phosphorylase (PNP), however no relationship between this binding and a mechanism of action has been established.
Clarithromycin, a semisynthetic macrolide antibiotic derived from erythromycin, inhibits bacterial protein synthesis by binding to the bacterial 50S ribosomal subunit. Binding inhibits peptidyl transferase activity and interferes with amino acid translocation during the translation and protein assembly process. Clarithromycin may be bacteriostatic or bactericidal depending on the organism and drug concentration.
Coniferaldehyde (CAS: 458-36-6), also known as 4-hydroxy-3-methoxycinnamaldehyde or ferulaldehyde, belongs to the class of organic compounds known as methoxyphenols. Methoxyphenols are compounds containing a methoxy group attached to the benzene ring of a phenol moiety. Coniferaldehyde is an extremely weak basic (essentially neutral) compound (based on its pKa). Outside of the human body, coniferaldehyde is found, on average, in the highest concentration within sherries. Coniferaldehyde has also been detected, but not quantified in, several different foods, such as highbush blueberries, lima beans, Chinese cabbages, loquats, and greenthread tea. This could make coniferaldehyde a potential biomarker for the consumption of these foods. BioTransformer predicts that coniferaldehyde is a product of caffeic aldehyde metabolism via a catechol-O-methylation-pattern2 reaction catalyzed by the enzyme catechol O-methyltransferase (PMID: 30612223).
Cortisone is a naturally occurring glucocorticoid. It has been used in replacement therapy for adrenal insufficiency and as an anti-inflammatory agent. Cortisone itself is inactive. It is converted in the liver into the active metabolite cortisol. Cortisone is a corticosteroid hormone released by the adrenal gland in response to stress. One of cortisone's effects on the body, and a potentially harmful side effect when administered clinically, is the suppression of the immune system. This is an explanation for the apparent correlation between high stress and sickness.
Creatinine, or creatine anhydride, is a breakdown product of creatine phosphate in muscle. The loss of a water molecule from creatine results in the formation of creatinine. Creatinine is transferred to the kidneys by blood plasma, whereupon it is eliminated from the body by glomerular filtration and partial tubular excretion. Creatinine is usually produced at a fairly constant rate by the body. Measuring serum creatinine is a simple test and it is the most commonly used indicator of renal function. A rise in blood creatinine levels is observed only with marked damage to functioning nephrons. Therefore, this test is not suitable for detecting early kidney disease. The typical reference range for women is considered about 45-90 µmol/L; for men 60-110 µmol/L. Creatine and creatinine are metabolized in the kidneys, muscle, liver, and pancreas.
Cystathionine is a dipeptide formed by serine and homocysteine. Cystathioninuria is a prominent manifestation of vitamin-B6 deficiency. The transsulfuration of methionine yields homocysteine, which combines with serine to form cystathionine, the proximate precursor of cysteine through the enzymatic activity of cystathionase. In conditions in which cystathionine gamma-synthase or cystathionase is deficient, for example, there is cystathioninuria. Although cystathionine has not been detected in normal human serum or plasma by most conventional methods, gas chromatographic/mass spectrometric methodology detected a mean concentration of cystathionine in normal human serum of 140 nM, with a range of 65 to 301 nM. Cystathionine concentrations in CSF have been 10, 1, and 0.5 uM, and "not detected". Only traces (i.e., <1 uM) of cystathionine are present in normal CSF.587. Gamma-cystathionase deficiency (also known as Cystathioninuria), which is an autosomal recessive disorder (NIH: 2428), provided the first instance in which, in a human, the major biochemical abnormality due to a defined enzyme defect was clearly shown to be alleviated by administration of large doses of pyridoxine. The response in gamma-cystathionase-deficient patients is not attributable to correction of a preexisting deficiency of this vitamin (OMMBID, Chap. 88).
Cysteic acid is a crystalline amino acid formed in the oxidation of cysteine; it is a precursor of taurine.
Cytarabine, or cytosine arabinoside, a pyrimidine nucleoside analog, is found in mushrooms. Cytarabine is isolated from the mushroom Xerocomus nigromaculatus of unknown palatability. Cytarabine is an antineoplastic anti-metabolite used in the treatment of several forms of leukemia including acute myelogenous leukemia and meningeal leukemia. Cytarabine is an antimetabolite antineoplastic agent that inhibits the synthesis of DNA. Its actions are specific for the S phase of the cell cycle to stop normal cell development and division. Cytarabine is metabolized intracellularly into its active triphosphate form (cytosine arabinoside triphosphate). This metabolite then damages DNA by multiple mechanisms, including the inhibition of alpha-DNA polymerase, inhibition of DNA repair through an effect on beta-DNA polymerase, and incorporation into DNA. The latter mechanism is probably the most important. Cytotoxicity is highly specific for the S phase of the cell cycle. Cytarabine is a chemotherapy agent used mainly in the treatment of hematological malignancies such as acute myeloid leukemia (AML) and non-Hodgkin lymphoma. It is also known as ara C. Cytosine arabinoside is an antimetabolic agent with the chemical name of 1 -arabinofuranosylcytosine. Its mode of action is due to its rapid conversion into cytosine arabinoside triphosphate, which damages DNA when the cell cycle holds in the S phase (synthesis of DNA). Rapidly dividing cells, which require DNA replication for mitosis, are therefore most affected. Cytosine arabinoside also inhibits both DNA and RNA polymerases and nucleotide reductase enzymes needed for DNA synthesis
Cytidine is a nucleoside that is composed of the base cytosine linked to the five-carbon sugar D-ribose. Cytidine is a pyrimidine that besides being incorporated into nucleic acids, can serve as a substrate for the salvage pathway of pyrimidine nucleotide synthesis. It is a precursor of cytidine triphosphate (CTP) needed in the phosphatidylcholine (PC) and phosphatidylethanolamine (PE) biosynthetic pathways. These variations probably reflect the species differences in cytidine deaminase, the enzyme that converts cytidine to uridine in the body. The transport of cytidine into the brain's extracellular fluid, and then into neurons and glia, are essential prerequisites for cytidine to be utilized in the brain. An efficient mechanism mediating the brain uptake of circulating cytidine has not yet been demonstrated. The biosynthesis of PC, the most abundant phosphatide in the brain, via the Kennedy pathway requires phosphocholine and cytidine triphosphate (CTP), a cytidine nucleotide involved in the rate-limiting step. The enzyme that converts CTP to endogenous CDP-choline (CTP:phosphocholine cytidylyltransferase) is unsaturated at physiological brain CTP levels. APOBEC is a family of enzymes that has been discovered with the ability to deaminate cytidines on RNA or DNA. The human apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3G protein (APOBEC3G, or hA3G), provides cells with an intracellular antiretroviral activity that is associated with the hypermutation of viral DNA through cytidine deamination. Indeed, hA3G belongs to a family of vertebrate proteins that contains one or two copies of a signature sequence motif unique to cytidine deaminases (CTDAs) (PMID: 16769123, 15780864, 16720547).
A compound composed of a two cyclic peptides attached to a phenoxazine that is derived from streptomyces parvullus. It binds to DNA and inhibits RNA synthesis (transcription), with chain elongation more sensitive than initiation, termination, or release. As a result of impaired mRNA production, protein synthesis also declines after dactinomycin therapy. (From AMA Drug Evaluations Annual, 1993, p2015)
Daidzein is one of several known isoflavones. Isoflavones compounds are found in a number of plants, but soybeans and soy products like tofu and textured vegetable protein are the primary food source. Up until recently, daidzein was considered to be one of the most important and most studied isoflavones, however more recently attention has shifted to isoflavone metabolites. Equol represents the main active product of daidzein metabolism, produced via specific microflora in the gut. The clinical effectiveness of soy isoflavones may be a function of the ability to biotransform soy isoflavones to the more potent estrogenic metabolite, equol, which may enhance the actions of soy isoflavones, owing to its greater affinity for estrogen receptors, unique antiandrogenic properties, and superior antioxidant activity. However, not all individuals consuming daidzein produce equol. Only approximately one-third to one-half of the population is able to metabolize daidzein to equol. This high variability in equol production is presumably attributable to interindividual differences in the composition of the intestinal microflora, which may play an important role in the mechanisms of action of isoflavones. But, the specific bacterial species in the colon involved in the production of equol are yet to be discovered. (PMID:18045128, 17579894). Daidzein is a biomarker for the consumption of soy beans and other soy products.
Delphinidin 3-glucoside is found in adzuki bean. Delphinidin 3-glucoside is isolated from grapes and many other plant species Delphinidin 3-glucoside is present in red wine.
2'-Deoxyguanosine 5'-monophosphate, also known as deoxyguanylic acid or 2'-deoxy-GMP, belongs to the class of organic compounds known as purine 2'-deoxyribonucleoside monophosphates. These are purine nucleotides with monophosphate group linked to the ribose moiety lacking a hydroxyl group at position 2. 2'-Deoxyguanosine 5'-monophosphate is a purine 2'-deoxyribonucleoside 5'-monophosphate having guanine as the nucleobase. It exists in all living species, ranging from bacteria to humans. Within humans, 2'-deoxyguanosine 5'-monophosphate participates in a number of enzymatic reactions. In particular, 2'-deoxyguanosine 5'-monophosphate can be converted into dGDP which is mediated by the enzyme guanylate kinase. In addition, 2'-deoxyguanosine 5'-monophosphate can be converted into deoxyguanosine through its interaction with the enzyme cytosolic purine 5'-nucleotidase. In humans, 2'-deoxyguanosine 5'-monophosphate is involved in the metabolic disorder called the gout or kelley-seegmiller syndrome pathway.
Desoximetasone is only found in individuals that have used or taken this drug. It is a topical anti-inflammatory glucocorticoid used in dermatoses, skin allergies, psoriasis, etc. [PubChem]The precise mechanism of the antiinflammatory activity of topical steroids in the treatment of steroid-responsive dermatoses, in general, is uncertain. However, corticosteroids are thought to act by the induction of phospholipase A<sub>2</sub> inhibitory proteins, collectively called lipocortins. This is achieved first by the drug binding to the glucocorticoid receptors which then translocates into the nucleus and binds to DNA causing various activations and repressions of genes. It is postulated that these proteins control the biosynthesis of potent mediators of inflammation such as prostaglandins and leukotrienes by inhibiting the release of their common precursor arachidonic acid. Arachidonic acid is released from membrane phospholipids by phospholipase A<sub>2</sub>.
Diazoxide is only found in individuals that have used or taken this drug. It is a benzothiadiazine derivative that is a peripheral vasodilator used for hypertensive emergencies. It lacks diuretic effect, apparently because it lacks a sulfonamide group. [PubChem]As a diuretic, diazoxide inhibits active chloride reabsorption at the early distal tubule via the Na-Cl cotransporter, resulting in an increase in the excretion of sodium, chloride, and water. Thiazides like diazoxide also inhibit sodium ion transport across the renal tubular epithelium through binding to the thiazide sensitive sodium-chloride transporter. This results in an increase in potassium excretion via the sodium-potassium exchange mechanism. The antihypertensive mechanism of diazoxide is less well understood although it may be mediated through its action on carbonic anhydrases in the smooth muscle or through its action on the large-conductance calcium-activated potassium (KCa) channel, also found in the smooth muscle. As a antihypoglycemic, diazoxide inhibits insulin release from the pancreas, probably by opening potassium channels in the beta cell membrane.
Diclofenac is only found in individuals that have used or taken this drug. It is a non-steroidal anti-inflammatory agent (NSAID) with antipyretic and analgesic actions. It is primarily available as the sodium salt. [PubChem]The antiinflammatory effects of diclofenac are believed to be due to inhibition of both leukocyte migration and the enzyme cylooxygenase (COX-1 and COX-2), leading to the peripheral inhibition of prostaglandin synthesis. As prostaglandins sensitize pain receptors, inhibition of their synthesis is responsible for the analgesic effects of diclofenac. Antipyretic effects may be due to action on the hypothalamus, resulting in peripheral dilation, increased cutaneous blood flow, and subsequent heat dissipation.
Dihydrocapsaicin is found in pepper (C. annuum). It is a potential nutriceutical. Dihydrocapsaicin is a capsaicinoid and analog and congener of capsaicin in chili peppers (Capsicum). Like capsaicin it is an irritant. Dihydrocapsaicin accounts for about 22% of the total capsaicinoids mixture and has about the same pungency as capsaicin. Pure dihydrocapsaicin is a lipophilic colorless odorless crystalline to waxy compound. It is soluble in dimethyl sulfoxide and 100 % ethanol.
3,4-Dihydro-2H-1-benzopyran-2-one, also known as 3,4-dihydrocoumarin or 1,2-benzodihydropyrone, belongs to the class of organic compounds known as 3,4-dihydrocoumarins. These are 3,4-dihydrogenated coumarins. Coumarin is a bicyclic compound that are 1-benzopyran carrying an oxo group at the 2-position. 3,4-Dihydro-2H-1-benzopyran-2-one exists in all living organisms, ranging from bacteria to humans. 3,4-Dihydro-2H-1-benzopyran-2-one is a sweet, almond, and cinnamon tasting compound. 3,4-Dihydro-2H-1-benzopyran-2-one has been detected, but not quantified, in several different foods, such as green vegetables, pulses, sour cherries, and tarragons. A chromanone that is the 3,4-dihydro derivative of coumarin.
L-Dihydroorotic acid, also known as (S)-4,5-dihydroorotate or dihydro-L-orotate, belongs to the class of organic compounds known as alpha amino acids and derivatives. These are amino acids in which the amino group is attached to the carbon atom immediately adjacent to the carboxylate group (alpha carbon), or a derivative thereof. 4,5-Dihydroorotic acid is a derivative of orotic acid which serves as an intermediate in pyrimidine biosynthesis. L-Dihydroorotic acid is a drug. L-Dihydroorotic acid exists in all living species, ranging from bacteria to humans. Within humans, L-dihydroorotic acid participates in a number of enzymatic reactions. In particular, L-dihydroorotic acid can be biosynthesized from ureidosuccinic acid; which is catalyzed by the enzyme cad protein. In addition, L-dihydroorotic acid and quinone can be converted into orotic acid through the action of the enzyme dihydroorotate dehydrogenase (quinone), mitochondrial. In humans, L-dihydroorotic acid is involved in the metabolic disorder called the beta-ureidopropionase deficiency pathway. Outside of the human body, L-dihydroorotic acid has been detected, but not quantified in several different foods, such as black chokeberries, vanilla, sweet basils, soy beans, and broad beans.
Docosahexaenoic acid (DHA) is an omega-3 essential fatty acid. Chemically, DHA is a carboxylic acid with a 22-carbon chain and six cis- double bonds with the first double bond located at the third carbon from the omega end. DHA is most often found in fish oil. It is a major fatty acid in sperm and brain phospholipids, especially in the retina. Dietary DHA can reduce the level of blood triglycerides in humans, which may reduce the risk of heart disease (Wikipedia). Docosahexaenoic acid is found to be associated with isovaleric acidemia, which is an inborn error of metabolism.
Adrenic acid, also known as 7,10,13,16-docosatetraenoic acid or adrenate, is a member of the class of compounds known as very long-chain fatty acids. Very long-chain fatty acids are fatty acids with an aliphatic tail that contains at least 22 carbon atoms. Adrenic acid is practically insoluble (in water) and a weakly acidic compound (based on its pKa). Adrenic acid can be found in blood and in human myelin tissue. Within the cell, adrenic acid is primarily located in the cytoplasm, in the membrane (predicted from logP), and in the peroxisome. It can also be found in the extracellular space. In humans, adrenic acid is involved in alpha-linolenic acid and linoleic acid metabolism. Docosatetraenoic acid designates any straight chain 22:4 fatty acid. In particular, all-cis-7,10,13,16-docosatetraenoic acid is an ω-6 fatty acid with the trivial name adrenic acid (AdA). This is a naturally occurring polyunsaturated fatty acid formed through a 2-carbon chain elongation of arachidonic acid. It is one of the most abundant fatty acids in the early human brain. This unsaturated fatty acid is also metabolized by cells into biologically active products, such as dihomoprostaglandins and dihomo-epoxyeicosatrienoic acids (dihomo-EETs) (Wikipedia). Adrenic acid, which is a prostacyclin inhibitor, appears to be a potential prothrombotic agent (PMID: 1642692).
Dofetilide is a class III antiarrhythmic agent that is approved by the Food and Drug Administration (FDA) for the maintenance of sinus rhythm in individuals prone to the formation of atrial fibrillation and flutter, and for the chemical cardioversion to sinus rhythm from atrial fibrillation and flutter. [Wikipedia]
Doxorubicin is only found in individuals that have used or taken this drug. It is antineoplastic antibiotic obtained from Streptomyces peucetius. It is a hydroxy derivative of daunorubicin. [PubChem]Doxorubicin has antimitotic and cytotoxic activity through a number of proposed mechanisms of action: Doxorubicin forms complexes with DNA by intercalation between base pairs, and it inhibits topoisomerase II activity by stabilizing the DNA-topoisomerase II complex, preventing the religation portion of the ligation-religation reaction that topoisomerase II catalyzes.
A butyrophenone with general properties similar to those of haloperidol. It is used in conjunction with an opioid analgesic such as fentanyl to maintain the patient in a calm state of neuroleptanalgesia with indifference to surroundings but still able to cooperate with the surgeon. It is also used as a premedicant, as an antiemetic, and for the control of agitation in acute psychoses. (From Martindale, The Extra Pharmacopoeia, 29th ed, p593)
5-Thymidylic acid (conjugate base thymidylate), also known as thymidine monophosphate (TMP), deoxythymidine monophosphate (dTMP), or deoxythymidylic acid (conjugate base deoxythymidylate), is a nucleotide that is used as a monomer in DNA. It is an ester of phosphoric acid with the nucleoside thymidine. dTMP consists of a phosphate group, the pentose sugar deoxyribose, and the nucleobase thymine. Unlike the other deoxyribonucleotides, thymidine monophosphate often does not contain the "deoxy" prefix in its name; nevertheless, its symbol often includes a "d" ("dTMP"). 5-Thymidylic acid belongs to the class of organic compounds known as pyrimidine 2'-deoxyribonucleoside monophosphates. These are pyrimidine nucleotides with a monophosphate group linked to the ribose moiety lacking a hydroxyl group at position 2. The neutral species of 5-Thymidylic acid (2'-deoxythymidine 5'-monophosphate). 5-Thymidylic acid exists in all living species, ranging from bacteria to humans. Within humans, 5-thymidylic acid participates in a number of enzymatic reactions. In particular, 5-thymidylic acid and dihydrofolic acid can be biosynthesized from dUMP and 5,10-methylene-THF by the enzyme thymidylate synthase. In addition, 5-thymidylic acid can be converted into dTDP; which is catalyzed by the enzyme thymidylate synthase. In humans, 5-thymidylic acid is involved in pyrimidine metabolism. Outside of the human body, 5-Thymidylic acid has been detected, but not quantified in several different foods, such as common buckwheats, corn salad, garden cress, squashberries, and star fruits.
Efavirenz (brand names Sustiva and Stocrin) is a non-nucleoside reverse transcriptase inhibitor (NNRTI) and is used as part of highly active antiretroviral therapy (HAART) for the treatment of a human immunodeficiency virus (HIV) type 1.
(-)-Epicatechin 3-O-gallate is found in almond. (-)-Epicatechin 3-O-gallate is isolated from tea and numerous other plant species including rhubarb and grapes.
(-)-Catechin 3-O-gallate is a polyphenol compound found in foods of plant origin  (PMID: 20428313)
Epigallocatechin gallate (EGCG) is the principal catechin in tea from Camellia sinensis, the most consumed beverage worldwide (after water). Depending on brew time and temperature, a single cup of green tea may contain 100-200 mg EGCG. To control the dose of EGCG administered in experimental studies, green tea solids (GTS) or capsules of green tea extract standardized to EGCG content are often employed. However, there is considerable variability in the EGCG content of commercially available dietary supplements, ranging from 12-143% of the tablet or capsule weight. While standardizing tea preparations to EGCG or using highly purified EGCG for research presents an important strategy for the conduct of precise studies as well as the ability to replicate experiments, it is worth noting this approach limits the potential contributions and possible synergy with other bioactive tea ingredients, including caffeine and other flavonoids. Human studies of the bioavailability of green tea catechins reveal these compounds to be poorly absorbed, with <0.1% of ingested catechins appearing in blood. Most ingested EGCG is rapidly cleared from blood with an elimination half-life of {approx}3 h and preferentially excreted via bile to the colon. The growing interest in the role of EGCG in health promotion and disease prevention is reflected by an exponential growth of research publications in this field. (J Am Coll Nutr. 2007 Aug;26(4):362S-365S).
Epirubicin is only found in individuals that have used or taken this drug. It is an anthracycline which is the 4&#39;-epi-isomer of doxorubicin. The compound exerts its antitumor effects by interference with the synthesis and function of DNA. [PubChem]Epirubicin has antimitotic and cytotoxic activity. It inhibits nucleic acid (DNA and RNA) and protein synthesis through a number of proposed mechanisms of action: Epirubicin forms complexes with DNA by intercalation between base pairs, and it inhibits topoisomerase II activity by stabilizing the DNA-topoisomerase II complex, preventing the religation portion of the ligation-religation reaction that topoisomerase II catalyzes. It also interferes with DNA replication and transcription by inhibiting DNA helicase activity.
Esomeprazole (brand names Nexium; Lucen; Esopral and Axagon in Italy) is a proton pump inhibitor which reduces gastric acid secretion through the inhibition of H+/K+-ATPase in gastric parietal cells. By inhibiting the functioning of this enzyme, the drug prevents the formation of gastric acid. Esomeprazole is used in the treatment of dyspepsia, peptic ulcer disease (PUD), gastroesophageal reflux disease (GORD/GERD), and Zollinger-Ellison syndrome. Esomeprazole is the S-enantiomer of omeprazole (marketed as Losec/Prilosec), and AstraZeneca claims improved efficacy of this single enantiomer product over the racemic mixture of omeprazole.
Estrone is a major mammalian estrogen. The conversion of the natural C19 steroids, testosterone and androstenedione into estrone is dependent on a complex key reaction catalyzed by the cytochrome P450 aromatase (EC 1.14.14.1, unspecific monooxygenase), which is expressed in many tissues of the adult human (e.g. ovary, fat tissue), but not in the liver. The ovaries after menopause continue to produce androstenedione and testosterone in significant amounts and these androgens are converted in fat, muscle, and skin into estrone. When women between the ages of 45 and 64 years have prophylactic oophorectomy (when hysterectomy is performed for benign disease to prevent the development of ovarian cancer), evidence suggests that oophorectomy increases the subsequent risk of coronary heart disease (CHD) and osteoporosis. Whereas 14,000 women die of ovarian cancer every year nearly 490,000 women die of heart disease and 48,000 women die within 1 year after hip fracture. Therefore, the decision to perform prophylactic oophorectomy should be approached with great caution for the majority of women who are at low risk of developing ovarian cancer. Steroid sulfatase (EC 3.1.6.2, STS) hydrolyzes steroid sulfates, such as estrone sulfate to estrone which can be converted to steroids with potent estrogenic properties, that is, estradiol; STS activity is much higher in breast tumors and high levels of STS mRNA expression in tumors are associated with a poor prognosis. The biological roles of estrogens in tumorigenesis are certainly different between the endometrium and breast, although both are considered "estrogen-dependent tissues". 17beta-hydroxysteroid dehydrogenases (EC 1.1.1.62, 17-HSDs) are enzymes involved in the formation of active sex steroids. estrone is interconverted by two enzymes 17-HSD types. Type 1 converts estrone to estradiol and Type 2 catalyzes the reverse reaction. (PMID: 17653961, 17513923, 17470679, 17464097).
Ethyl tetradecanoate, also known as myristate ethyl ester or ethyl myristate, belongs to the class of organic compounds known as fatty acid esters. These are carboxylic ester derivatives of a fatty acid. Ethyl tetradecanoate is a very hydrophobic molecule, practically insoluble in water, and relatively neutral.
Ethyl glucuronide is a natural human metabolite of Ethanol generated in the liver by UDP glucuonyltransferase. Glucuronidation is used to assist in the excretion of toxic substances, drugs or other substances that cannot be used as an energy source. Glucuronic acid is attached via a glycosidic bond to the substance, and the resulting glucuronide, which has a much higher water solubility than the original substance, is eventually excreted by the kidneys. Ethyl glucuronide is a general biomarker for the consumption of alcohol
Ethyl butyrate, also known as ethyl butanoate, or butyric ether, is an ester with the chemical formula CH3CH2CH2COOCH2CH3, with one oxygen having a double bond. It is soluble in propylene glycol, paraffin oil and kerosene. Ethyl butyrate is present in many fruits e.g. apple, apricot, banana, plum, tangerine etc. Ethyl butyrate is a flavouring ingredient and it can be synthesized by reacting ethanol and butyric acid. This is a condensation reaction, meaning water is produced in the reaction as a byproduct.
Ethyl dodecanoate, also known as ethyl laurinate or laate ethyl ester, belongs to the class of organic compounds known as fatty acid esters. These are carboxylic ester derivatives of a fatty acid. Ethyl dodecanoate is a very hydrophobic molecule, practically insoluble in water, and relatively neutral.
Etoposide, also known as vepesid or VP-16, belongs to the class of organic compounds known as podophyllotoxins. These are tetralin lignans in which the benzene moiety of the tetralin skeleton is fused to a 1,3-dioxolane and the cyclohexane is fused to a butyrolactone (pyrrolidin-2-one). Etoposide is a drug. Within humans, etoposide participates in a number of enzymatic reactions. In particular, etoposide can be converted into etoposide ortho-quinone; which is mediated by the enzymes prostaglandin g/h synthase 1 and prostaglandin g/h synthase 2. In addition, etoposide and uridine diphosphate glucuronic acid can be converted into etoposide glucuronide and uridine 5'-diphosphate; which is mediated by the enzyme UDP-glucuronosyltransferase 1-1. In humans, etoposide is involved in etoposide metabolism pathway. Etoposide is formally rated as a carcinogen (by IARC 1) and is also a potentially toxic compound. Etoposide is used as a form of chemotherapy for cancers such as Kaposi's sarcoma, Ewing's sarcoma, lung cancer, testicular cancer, lymphoma, nonlymphocytic leukemia, and glioblastoma multiforme. It is given intravenously (IV) or orally in capsule or tablet form. It is believed to work by damaging DNA. Etoposide was approved for medical use in the United States in 1983. They can include low blood cell counts, vomiting, loss of appetite, diarrhea, hair loss, and fever.
Ezetimibe is an anti-hyperlipidemic medication which is used to lower cholesterol levels. Specifically, it appears to bind to a critical mediator of cholesterol absorption, the Niemann-Pick C1-Like 1 (NPC1L1) protein on the gastrointestinal tract epithelial cells as well as in hepatocytes.
Famotidine is a histamine H2-receptor antagonist that inhibits stomach acid production, and is commonly used in the treatment of peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD/GORD). It is commonly marketed by Merck under the trade names Pepcidine and Pepcid.
Fenoldopam is only found in individuals that have used or taken this drug. It is a dopamine D1 receptor agonist that is used as an antihypertensive agent. It lowers blood pressure through arteriolar vasodilation. [PubChem]Fenoldopam is a rapid-acting vasodilator. It is an agonist for D<sub>1</sub>-like dopamine receptors and binds with moderate affinity to &alpha;<sub>2</sub>-adrenoceptors. It has no significant affinity for D<sub>2</sub>-like receptors, &alpha;<sub>1</sub> and &beta;-adrenoceptors, 5<sub>HT1</sub> and 5<sub>HT2</sub> receptors, or muscarinic receptors. Fenoldopam is a racemic mixture with the R-isomer responsible for the biological activity. The R-isomer has approximately 250-fold higher affinity for D<sub>1</sub>-like receptors than does the S-isomer. In non-clinical studies, fenoldopam had no agonist effect on presynaptic D<sub>2</sub>-like dopamine receptors, or &alpha; or &beta; -adrenoceptors, nor did it affect angiotensin-converting enzyme activity. Fenoldopam may increase norepinephrine plasma concentration.
trans-Ferulic acid is a highly abundant phenolic phytochemical which is present in plant cell walls. Ferulic acid is a phenolic acid that can be absorbed by the small intestine and excreted through the urine. It is one of the most abundant phenolic acids in plants, varying from 5 g/kg in wheat bran to 9 g/kg in sugar-beet pulp and 50 g/kg in corn kernel. It occurs primarily in seeds and leaves both in its free form (albeit rarely) and covalently linked to lignin and other biopolymers. It is usually found as ester cross-links with polysaccharides in the cell wall, such as arabinoxylans in grasses, pectin in spinach and sugar beet, and xyloglucans in bamboo. It also can cross-link with proteins. Due to its phenolic nucleus and an extended side chain conjugation (carbohydrates and proteins), it readily forms a resonance-stabilized phenoxy radical which accounts for its potent antioxidant potential. Food supplementation with curcumin and ferulic acid is considered a nutritional approach to reducing oxidative damage and amyloid pathology in Alzheimer disease (PMID:17127365, 1398220, 15453708, 9878519). Ferulic acid can be found in Pseudomonas and Saccharomyces (PMID:8395165).
Fluphenazine is only found in individuals that have used or taken this drug. It is a phenothiazine used in the treatment of psychoses. Its properties and uses are generally similar to those of chlorpromazine. [PubChem]Fluphenazine blocks postsynaptic mesolimbic dopaminergic D1 and D2 receptors in the brain; depresses the release of hypothalamic and hypophyseal hormones and is believed to depress the reticular activating system thus affecting basal metabolism, body temperature, wakefulness, vasomotor tone, and emesis.
Flurbiprofen, a propionic acid derivative, is a nonsteroidal anti-inflammatory agent (NSAIA) with antipyretic and analgesic activity. Oral formulations of flurbiprofen may be used for the symptomatic treatment of rheumatoid arthritis, osteoarthritis and anklylosing spondylitis. Flurbiprofen may also be used topically prior to ocular surgery to prevent or reduce intraoperative miosis. Flurbiprofen is structurally and pharmacologically related to fenoprofen, ibuprofen, and ketoprofen.
Formononetin are abundant in vegetables. It is a phyto-oestrogen that is a polyphenolic non-steroidal plant compound with oestrogen-like biological activity (PMID: 16108819). It can be the source of considerable estrogenic activity (http://www.herbalchem.net/Intermediate.htm).
Formoterol is a long-acting (12 hours) beta2-agonist used in the management of asthma and/or chronic obstructive pulmonary disease (COPD). Inhaled formoterol works like other beta2-agonists, causing bronchodilatation through relaxation of the smooth muscle in the airway so as to treat the exacerbation of asthma.
Fumaric acid is a dicarboxylic acid. It is a precursor to L-malate in the Krebs tricarboxylic acid (TCA) cycle. It is formed by the oxidation of succinic acid by succinate dehydrogenase. Fumarate is converted by the enzyme fumarase to malate. Fumaric acid has recently been identified as an oncometabolite or an endogenous, cancer causing metabolite. High levels of this organic acid can be found in tumors or biofluids surrounding tumors. Its oncogenic action appears to due to its ability to inhibit prolyl hydroxylase-containing enzymes. In many tumours, oxygen availability becomes limited (hypoxia) very quickly due to rapid cell proliferation and limited blood vessel growth. The major regulator of the response to hypoxia is the HIF transcription factor (HIF-alpha). Under normal oxygen levels, protein levels of HIF-alpha are very low due to constant degradation, mediated by a series of post-translational modification events catalyzed by the prolyl hydroxylase domain-containing enzymes PHD1, 2 and 3, (also known as EglN2, 1 and 3) that hydroxylate HIF-alpha and lead to its degradation. All three of the PHD enzymes are inhibited by fumarate. Fumaric acid is found to be associated with fumarase deficiency, which is an inborn error of metabolism. It is also a metabolite of Aspergillus.
Gallic acid is an organic acid, also known as 3,4,5-trihydroxybenzoic acid, found in gallnuts, sumac, witch hazel, tea leaves, oak bark, and other plants. The chemical formula is C6H2(OH)3CO2H. Gallic acid is widely distributed in plants and is found both free and as part of tannins. It is commonly used in the pharmaceutical industry. Gallic acid can also be used to synthesize the hallucinogenic alkaloid mescaline, also known as 3,4,5-trimethoxyphenethylamine. Salts and esters of gallic acid are termed gallates. Gallic acid has been found to be s metabolite of Aspergillus (PMID:24031294).
N2-gamma-Glutamylglutamine, also known as gamma-L-Glu-L-Gln or L-gamma-glutamyl-L-glutamine, belongs to the class of organic compounds known as dipeptides. These are organic compounds containing a sequence of exactly two alpha-amino acids joined by a peptide bond. N2-gamma-Glutamylglutamine is a very strong basic compound (based on its pKa). N2-gamma-Glutamylglutamine is a dipeptide obtained from the condensation of the gamma-carboxy group of glutamic acid with the alpha-amino group of glutamine. Some dipeptides are known to have physiological or cell-signalling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis.
gamma-Glutamyltyrosine is a dipeptide composed of gamma-glutamate and tyrosine, and is a proteolytic breakdown product of larger proteins. It belongs to the family of N-acyl-alpha amino acids and derivatives. These are compounds containing an alpha amino acid which bears an acyl group at its terminal nitrogen atom. gamma-Glutamyltyrosine is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis.
gamma-Glutamylleucine is a dipeptide composed of gamma-glutamate and leucine, and is a proteolytic breakdown product of larger proteins. It belongs to the family of N-acyl-alpha amino acids and derivatives. These are compounds containing an alpha amino acid which bears an acyl group at its terminal nitrogen atom. gamma-Glutamylleucine is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis. gamma-Glutamylleucine is a biomarker for the consumption of whey protein. It is found in urine (PMID: 3782411).
gamma-Glutamylmethionine is a dipeptide composed of gamma-glutamate and methionine, and is a proteolytic breakdown product of larger proteins. It belongs to the family of N-acyl-alpha amino acids and derivatives. These are compounds containing an alpha amino acid which bears an acyl group at its terminal nitrogen atom. gamma-Glutamylmethionine is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis. gamma-Glutamylmethionine is found in onion-family vegetables. It is isolated from the seeds of onion (Allium cepa), kidney bean (Phaseolus vulgaris), mung bean (Vigna radiata), garlic (Allium sativum), and black gram (Vigna mungo).
Gentisic acid, also known as gentisate or 2,5-dioxybenzoate, belongs to the class of organic compounds known as hydroxybenzoic acid derivatives. Hydroxybenzoic acid derivatives are compounds containing a hydroxybenzoic acid (or a derivative), which is a benzene ring bearing a carboxyl and a hydroxyl groups. Gentisic acid is also classified as a dihydroxybenzoic acid.  It is a derivative of benzoic acid and a minor (1%) product of the metabolic break down of aspirin, which is excreted by the kidneys. Gentisic acid is found in essentially all organisms ranging from bacteria to fungi to plants to animals. Gentisic acid has been associated with a number of useful effects on human health and exhibits anti-inflammatory, antigenotoxic, hepatoprotective, neuroprotective, antimicrobial, and especially antioxidant activities (PMID: 31825145). It is widely distributed in plants as a secondary plant product such as Gentiana spp., Citrus spp., Vitis vinifera, Pterocarpus santalinus, Helianthus tuberosus, Hibiscus rosa-sinensis, Olea europaea, and Sesamum indicum and in fruits such as avocados, batoko plum, kiwi fruits, apple, bitter melon, black berries, pears, and some mushrooms (PMID: 31825145). Gentisic acid is found in higher concentrations in a number of foods such as tarragons, common thymes, and common sages and in a lower concentration in grape wines, rosemaries, and sweet marjorams. Gentisic acid has also been shown to act as a pathogen-inducible signal for the activation of plant defenses in tomato plants and cucumbers (PMID: 16321412; https://doi.org/10.1094/MPMI.1999.12.3.227).
Gibberellic acid, also known as gibberellin A3, GA, or GA3, is a very potent hormone whose natural occurrence in plants controls their development. Since GA regulates growth, applications of very low concentrations can have a profound effect while too much will have the opposite effect. Gibberellic acid is a hormone found in plants. Gibberellic acid is a simple gibberellin promoting the growth and elongation of cells. It affects the decomposition of plants. It also helps plants grow if used in small amounts but eventually, plants grow a tolerance for it. Gibberellic acid stimulates the cells of germinating seeds to produce mRNA molecules that code for hydrolytic enzymes.
Glimepiride is only found in individuals that have used or taken this drug. It is the first III generation sulphonyl urea it is a very potent sulphonyl urea with long duration of action.The mechanism of action of glimepiride in lowering blood glucose appears to be dependent on stimulating the release of insulin from functioning pancreatic beta cells, and increasing sensitivity of peripheral tissues to insulin. Glimepiride likely binds to ATP-sensitive potassium channel receptors on the pancreatic cell surface, reducing potassium conductance and causing depolarization of the membrane. Membrane depolarization stimulates calcium ion influx through voltage-sensitive calcium channels. This increase in intracellular calcium ion concentration induces the secretion of insulin.
Gluconolactone, also known as glucono-delta-lactone or GDL (gluconate), belongs to the class of organic compounds known as gluconolactones. These are polyhydroxy acids (PHAs) containing a gluconolactone molecule, which is characterized by a tetrahydropyran substituted by three hydroxyl groups, one ketone group, and one hydroxymethyl group. Gluconolactone is a lactone of D-gluconic acid. Gluconolactone can be produced by enzymatic oxidation of D-glucose via the enzyme glucose oxidase. It is a fundamental metabolite found in all organisms ranging from bacteria to plants to animals. Gluconolactone has metal chelating, moisturizing and antioxidant activities. Its ability in free radicals scavenging accounts for its antioxidant properties. Gluconolactone, is also used as a food additive with the E-number E575. In foods it is used as a sequestrant, an acidifier or a curing, pickling, or leavening agent. Gluconolactone is also used as a coagulant in tofu processing. Gluconolactone is widely used as a skin exfoliant in cosmetic products, where it is noted for its mild exfoliating and hydrating properties. Pure gluconolactone is a white odorless crystalline powder. It is pH-neutral, but hydrolyses in water to gluconic acid which is acidic, adding a tangy taste to foods. Gluconic acid has roughly a third of the sourness of citric acid. One gram of gluconolactone yields roughly the same amount of metabolic energy as one gram of sugar.
Glucoraphanin belongs to the class of organic compounds known as alkylglucosinolates. These are organic compounds containing a glucosinolate moiety that carries an alkyl chain. Outside of the human body, glucoraphanin has been detected, but not quantified in, several different foods, such as radish, common cabbages, Brassicas, Chinese cabbages, and cabbages. This could make glucoraphanin a potential biomarker for the consumption of these foods.
Glucosamine 6-phosphate (CAS: 3616-42-0) is normally produced in endothelial cells via de novo glucosamine synthesis by the enzyme fructose-6-phosphate amidotransferase and the modulation of this pathway by hyperglycemia and glutamine. Glutamine-fructose-6-phosphate amidotransferase (GFAT) catalyzes the first committed step in the pathway for biosynthesis of hexosamines in mammals.It is a member of the N-terminal nucleophile class of amidotransferases, GFAT transfers the amino group from the L-glutamine amide to D-fructose 6-phosphate, producing glutamic acid and glucosamine 6-phosphate. As glucosamine inhibits endothelial nitric oxide synthesis it has important implications for impaired endothelium-dependent relaxation and vascular dysfunction in diabetes mellitus (PMID:11270676, 11842094).
Glucose 1-phosphate (also called cori ester) is a glucose molecule with a phosphate group on the 1'-carbon. It can exist in either the α- or β-anomeric form. Glucose 1-phosphate belongs to the class of organic compounds known as monosaccharide phosphates. These are monosaccharides comprising a phosphated group linked to the carbohydrate unit. Glucose 1-phosphate is the direct product of the reaction in which glycogen phosphorylase cleaves off a molecule of glucose from a greater glycogen structure. It cannot travel down many metabolic pathways and must be interconverted by the enzyme phosphoglucomutase in order to become glucose 6-phosphate. Free glucose 1-phosphate can also react with UTP to form UDP-glucose. It can then return to the greater glycogen structure via glycogen synthase.
Oxidized glutathione, also known as glutathione disulfide or GSSG, belongs to the class of organic compounds known as peptides. Peptides are compounds containing an amide derived from two or more amino carboxylic acid molecules (the same or different) by the formation of a covalent bond from the carbonyl carbon of one to the nitrogen atom of another. In humans, oxidized glutathione is involved in the metabolic disorder called leukotriene C4 synthesis deficiency pathway. Outside of the human body, oxidized glutathione has been detected, but not quantified in several different foods, such as leeks, star anises, mamey sapotes, climbing beans, and common persimmons. Oxidized glutathione is a glutathione dimer formed by a disulfide bond between the cysteine sulfhydryl side chains during the course of being oxidized. Glutathione participates in leukotriene synthesis and is a cofactor for the enzyme glutathione peroxidase. It is also important as a hydrophilic molecule that is added to lipophilic toxins and waste in the liver during biotransformation before they can become part of the bile. Glutathione is also needed for the detoxification of methylglyoxal, a toxin produced as a by-product of metabolism. This detoxification reaction is carried out by the glyoxalase system. Glyoxalase I (EC 4.4.1.5) catalyzes the conversion of methylglyoxal and reduced glutathione into S-D-lactoyl-glutathione. Glyoxalase II (EC 3.1.2.6) catalyzes the hydrolysis of S-D-lactoyl-glutathione into glutathione and D-lactate.
Glycylglycylglycine, also known as GGG or triglycine, belongs to the class of organic compounds known as oligopeptides. These are organic compounds containing a sequence of between three and ten alpha-amino acids joined by peptide bonds. A tripeptide in which three glycine units are linked via peptide bonds in a linear sequence. Glycylglycylglycine has been detected, but not quantified, in fruits. This could make glycylglycylglycine a potential biomarker for the consumption of these foods. Glycylglycylglycine is a potentially toxic compound.
Glycyl-Isoleucine is a dipeptide composed of glycine and isoleucine. It is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis. This dipeptide has not yet been identified in human tissues or biofluids and so it is classified as an 'Expected' metabolite.
Glycylleucine is a dipeptide composed of glycine and leucine. It is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis. It appears to be a common substrate for glycyl-leucine dipeptidase.
Glycyltyrosine is a dipeptide composed of glycine and tyrosine. It is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis.
Glycitein is a soy isoflavone. It is a minor component in most soy products. It's role of reducing low-density lipoprotein cholesterol is not clear. Glycitein is metabolized by human gut microorganisms and may follow metabolic pathways similar to other soy isoflavones (PMID: 12011578; 16248547). Glycitein is a biomarker for the consumption of soy beans and other soy products.
Goserelin is a synthetic hormone. In men, it stops the production of the hormone testosterone, which may stimulate the growth of cancer cells. In women, goserelin decreases the production of the hormone estradiol (which may stimulate the growth of cancer cells) to levels similar to a postmenopausal state. When the medication is stopped, hormone levels return to normal.
Henicosanoic acid, also known as N-heneicosanoate or 21:0,is a long-chain fatty acid that is henicosane in which one of the methyl groups has been oxidised to give the corresponding carboxylic acid. It is a straight-chain saturated fatty acid and a long-chain fatty acid. It is a conjugate acid of a henicosanoate. Heneicosanoic acid belongs to the class of organic compounds known as long-chain fatty acids. These are fatty acids with an aliphatic tail that contains between 13 and 21 carbon atoms. Heneicosanoic acid is a very hydrophobic molecule, practically insoluble in water, and relatively neutral. Heneicosanoic acid is a potentially toxic compound.
L-homoarginine, also known as N6-(aminoiminomethyl)-L-lysine or N6-amidino-L-lysine, is a member of the class of compounds known as L-alpha-amino acids. L-alpha-amino acids are alpha amino acids which have the L-configuration of the alpha-carbon atom. More specifically, L-homoarginine is a naturally occurring, non-proteinogenic, cationic amino acid. It is formed in the liver in a reaction catalyzed by L-arginine:glycine amidinotransferase (AGAT) when transferring the amidino group from arginine to lysine. It is an alternative substrate for nitric oxide (NO) synthase. L-homoarginine increases the availability of NO and thereby affects endothelial function. High homoarginine levels may exert positive actions that are relevant to cardiovascular health, including enhanced endothelial function, inhibition of platelet aggregation and stimulation of insulin secretion (PMID: 30866658). Recent studies have demonstrated that low serum homoarginine levels are a strong predictor of cardiovascular mortality (PMID: 24583919). L-homoarginine is a substrate of the human cationic amino acid CAT1 [solute carrier family 7 (SLC7A1)], CAT2A (SLC7A2A) or CAT2B (SLC7A2B) (PMID: 28684763). According to published human metabolomic data, L-homoarginine can be found primarily in blood, cerebrospinal fluid (CSF), and urine, as well as in human intestinal and testes tissues. Moreover, L-homoarginine has been found to be associated with liver cirrhosis and the genetic disorder, hyperargininemia. Homoarginine is an organ-specific uncompetitive inhibitor of human liver and bone alkaline phosphohydrolase (PMID: 5063678).
Homoserine is a more reactive variant of the amino acid serine. In this variant, the hydroxyl side chain contains an additional CH2 group which brings the hydroxyl group closer to its own carboxyl group, allowing it to chemically react to form a five-membered ring. This occurs at the point that amino acids normally join to their neighbours in a peptide bond. Homoserine is therefore unsuitable for forming proteins and has been eliminated from the repertoire of amino acids used by living things. Homoserine is the final product on the C-terminal end of the N-terminal fragment following a cyanogen bromide cleavage. (wikipedia). Homoserine is also a microbial metabolite.
Homovanillic acid (HVA), also known as homovanillate, belongs to the class of organic compounds known as methoxyphenols. Methoxyphenols are compounds containing a methoxy group attached to the benzene ring of a phenol moiety. HVA is also classified as a catechol.  HVA is a major catecholamine metabolite that is produced by a consecutive action of monoamine oxidase and catechol-O-methyltransferase on dopamine. HVA is typically elevated in patients with catecholamine-secreting tumors (such as neuroblastoma, pheochromocytoma, and other neural crest tumors). HVA levels are also used in monitoring patients who have been treated for these kinds tumors. HVA levels may also be altered in disorders of catecholamine metabolism such as monoamine oxidase-A (MOA) deficiency. MOA deficiency can cause decreased urinary HVA values, while a deficiency of dopamine beta-hydrolase (the enzyme that converts dopamine to norepinephrine) can cause elevated urinary HVA values. Within humans, HVA participates in a number of enzymatic reactions. In particular, HVA and pyrocatechol can be biosynthesized from 3,4-dihydroxybenzeneacetic acid and guaiacol. This reaction is catalyzed by the enzyme known as catechol O-methyltransferase. In addition, HVA can be biosynthesized from homovanillin through the action of the enzyme known aldehyde dehydrogenase. HVA has recently been found in a number of beers and appears to arise from the fermentation process (https://doi.org/10.1006/fstl.1999.0593). HVA is also a metabolite of Bifidobacterium (PMID: 24958563) and the bacterial breakdown of dietary flavonoids. Dietary flavonols commonly found in tomatoes, onions, and tea, can lead to significantly elevated levels of urinary HVA (PMID: 20933512). Likewise, the microbial digestion of hydroxytyrosol (found in olive oil) can also lead to elevated levels of HVA in humans (PMID: 11929304).
Hydrocinnamic acid, also known as 3-phenylpropanoic acid or dihydrocinnamic acid, belongs to the class of organic compounds known as phenylpropanoic acids. Phenylpropanoic acids are compounds with a structure containing a benzene ring conjugated to a propanoic acid (C6-C3). Phenylpropanoic acid can be prepared from cinnamic acid by hydrogenation. Hydrocinnamic acid is a sweet, balsamic, and cinnamon tasting compound. This compound is used frequently in cosmetic products such as perfumes, bath gels, detergent powders, liquid detergents, fabric softeners, and soaps as it gives off a floral scent. A characteristic reaction of phenylpropanoic acid is its cyclization to indanones. Phenylpropanoic acid is used in the food industry to preserve and maintain the original aroma quality of frozen foods. Phenylpropanoic acid is also added to food for technological purposes in a wide variety including manufacturing, processing, preparation, treatment, packaging, transportation or storage, and food additives. This compound is used as a sweetener as well to sweeten food and can be found in tabletop sweeteners.
4-Hydroxyproline (hydroxyproline or Hyp) is a major component of the protein collagen. Hydroxyproline is produced by hydroxylation of the amino acid proline and is, therefore, a post-translationally modified, non-essential amino acid. Hydroxyproline and proline play key roles in collagen stability. In particular, they permit the sharp twisting of the collagen helix. Hydroxyproline is found in few proteins other than collagen. The only other mammalian protein which includes hydroxyproline is elastin. For this reason, hydroxyproline content has been used as an indicator to determine collagen and/or gelatin amount in tissue or biological samples. Increased serum and urine levels of hydroxyproline have been found in Paget's disease (PMID: 436278). Hydroxyproline (Hyp) content in biological fluids is used as a parameter of collagen catabolism, especially bone resorption or tissue degradation. Bedridden and elderly individuals show significantly elevated serum levels of hydroxyproline in comparison to normal, active individuals (PMID: 10706420). Elevated levels of urinary hydroxyproline are also indicative of muscle damage (PMID: 21988268). Increased reactive oxygen species (ROS) are also known to accelerate collagen degradation. Hydroxyproline levels increase in cases of depression and stress (PMID: 21483218). 4-Hydroxyproline is found to be associated with Alzheimer's disease, and also hydroxyprolinemia and iminoglycinuria which are both inborn errors of metabolism. 4-Hydroxyproline is also involved in metabolic disorders such as hyperprolinemia type I, hyperornithinemia with gyrate atrophy (HOGA), L-arginine:glycine amidinotransferase deficiency, creatine deficiency, and guanidinoacetate methyltransferase deficiency. A deficiency in ascorbic acid can result in impaired hydroxyproline formation (PubChem). trans-4-Hydroxy-L-proline is a biomarker for the consumption of processed meat.
Idarubicin is only found in individuals that have used or taken this drug. It is an orally administered anthracycline antineoplastic. The compound has shown activity against breast cancer, lymphomas and leukemias, together with the potential for reduced cardiac toxicity. [PubChem]Idarubicin has antimitotic and cytotoxic activity through a number of proposed mechanisms of action: Idarubicin forms complexes with DNA by intercalation between base pairs, and it inhibits topoisomerase II activity by stabilizing the DNA-topoisomerase II complex, preventing the religation portion of the ligation-religation reaction that topoisomerase II catalyzes.
Imatinib is a drug used to treat certain types of cancer. It is currently marketed by Novartis as Gleevec (USA) or Glivec (Europe/Australia) as its mesylate salt, imatinib mesilate (INN). It is occasionally referred to as CGP57148B or STI571 (especially in older publications). It is used in treating chronic myelogenous leukemia (CML), gastrointestinal stromal tumors (GISTs) and a number of other malignancies. It is the first member of a new class of agents that act by inhibiting particular tyrosine kinase enzymes, instead of non-specifically inhibiting rapidly dividing cells.
Indirubin or indigo red is an organic compound with a distinctive deep red/orange color. It is an oxindole dimer consisting of two fused oxindole rings. Indoles are compounds which consist of a pyrrole ring fused to benzene to form 2,3-benzopyrrole. Indirubin is found in both plants and animals and has been detected in human urine and human tissues (PMID: 11076521; PMID: 8667928). The precursor to indirubin is indican, a colorless, water-soluble derivative of the amino acid tryptophan which is converted to indole via microbial metabolism. Indican readily hydrolyzes to release β-D-glucose and indoxyl. Oxidation of indoxyl by CYP450 enzymes in the liver or kidneys can convert indoxyl to indirubin (PMID: 11076521). Likewise, exposure to air can convert indoxyl to indirubin. In addition to the mammalian production of minute amounts of indirubin, this chemical can also be recovered in far larger amounts from plants. Historically, indirubin has been extracted from the leaves of certain plants of the Indigofera genus, in particular Indigofera tinctoria. Indigofera plants were commonly grown and used throughout the world for the production of dyes. Indirubin is a chemical constituent of indigo naturalis (also known as qing dai), which has been used for hundreds of years in traditional Chinese medicine. It is produced by collecting the waste products from the bacterial degradation of specific forms of vegetation. Indirubin has shown anti-inflammatory and anti-angiogenesis properties in vitro (PMID: 21207415). It has also been studied for potential use in the treatment of ulcerative colitis (PMID: 23674882).
Indinavir is only found in individuals that have used or taken this drug. It is a potent and specific HIV protease inhibitor that appears to have good oral bioavailability. [PubChem]Indinavir inhibits the HIV viral protease enzyme which prevents cleavage of the gag-pol polyprotein, resulting in noninfectious, immature viral particles.
Indole-3-acetamide, also known as 2-(3-indolyl)acetamide or IAM, belongs to the class of organic compounds known as 3-alkylindoles. 3-Alkylindoles are compounds containing an indole moiety that carries an alkyl chain at the 3-position. Indole-3-acetamide has been detected, but not quantified, in several different foods, such as Alaska wild rhubarbs, lingonberries, butternut squash, pineapples, and agaves. Indole-3-acetamide is also found in the common pea and has been isolated from the etiolated seedlings of the black gram (Phaseolus mungo).
Indoleacetic acid (IAA) is a breakdown product of tryptophan metabolism and is often produced by the action of bacteria in the mammalian gut. Higher levels of IAA are associated with bacteria from Clostridium species including C. stricklandii, C. lituseburense, C. subterminale, and C. putrefaciens (PMID: 12173102). IAA can be found in Agrobacterium, Azospirillum, Bacillus, Bradyrhizobium, Clostridium, Enterobacter, Pantoea, Pseudomonas, Rhizobium (PMID: 12173102, PMID: 17555270, PMID: 12147474, PMID: 19400643, PMID: 9450337, PMID: 21397014) (https://link.springer.com/chapter/10.1007/978-1-4612-3084-7_7) (https://escholarship.org/uc/item/1bf1b5m3). Some endogenous production of IAA in mammalian tissues also occurs. It may be produced by the decarboxylation of tryptamine or the oxidative deamination of tryptophan. IAA frequently occurs at low levels in urine and has been found in elevated levels in the urine of patients with phenylketonuria (PMID: 13610897). IAA has also been identified as a uremic toxin according to the European Uremic Toxin Working Group (PMID: 22626821). Using material extracted from human urine, it was discovered by Kogl in 1933 that indoleacetic acid is also an important plant hormone (PMID: 13610897). Specifically, IAA is a member of the group of phytohormones called auxins. IAA is generally considered to be the most important native auxin. Plant cells synthesize IAA from tryptophan (Wikipedia). IAA and some derivatives can be oxidized by horseradish peroxidase (HRP) into cytotoxic species. IAA is only toxic after oxidative decarboxylation; the effect of IAA/HRP is thought to be due in part to the formation of methylene-oxindole, which may conjugate with DNA bases and protein thiols. IAA/HRP could be used as the basis for targeted cancer, a potential new role for plant auxins in cancer therapy (PMID: 11163327).
Indole-3-carboxaldehyde (IAld or I3A), also known as 3-formylindole or 3-indolealdehyde, belongs to the class of organic compounds known as indoles. Indoles are compounds containing an indole moiety, which consists of a pyrrole ring fused to benzene to form 2,3-benzopyrrole. In humans, I3A is a biologically active metabolite which acts as a receptor agonist at the aryl hydrocarbon receptor in intestinal immune cells. It stimulates the production of interleukin-22 which facilitates mucosal reactivity (PMID:27102537). I3A is a microbially derived tryptophan metabolite produced by Clostridium and Lactobacillus (PMID:30120222, 27102537). I3A has also been found in the urine of patients with untreated phenylketonuria (PMID:5073866). I3A has been detected, but not quantified, in several different foods, such as beans, Brussels sprouts, cucumbers, cereals and cereal products, and white cabbages. This could make I3A a potential biomarker for the consumption of these foods.
Indole-3-carboxylic acid, also known as 3-carboxyindole or 3-indolecarboxylate, belongs to the class of organic compounds known as indolecarboxylic acids and derivatives. Indolecarboxylic acids and derivatives are compounds containing a carboxylic acid group (or a derivative thereof) linked to an indole. Naphthylmethylindoles: Any compound containing a 1H-indol-3-yl-(1-naphthyl)methane structure with substitution at the nitrogen atom of the indole ring by an alkyl, haloalkyl, alkenyl, cycloalkylmethyl, cycloalkylethyl, 1-(N-methyl-2-piperidinyl)methyl, or 2-(4-morpholinyl)ethyl group whether or not further substituted in the indole ring to any extent and whether or not substituted in the naphthyl ring to any extent. One example given is JWH-250. Outside of the human body, indole-3-carboxylic acid has been detected, but not quantified in several different foods, such as brassicas, broccoli, pulses, common beets, and barley. This could make indole-3-carboxylic acid a potential biomarker for the consumption of these foods. Notice the pentyl group substituted onto the nitrogen atom of the indole ring. Note that this definition encompasses only those compounds that have OH groups attached to both the phenyl and the cyclohexyl rings, and so does not include compounds such as O-1871 which lacks the cyclohexyl OH group, or compounds such as JWH-337 or JWH-344 which lack the phenolic OH group.
The thiamin diphosphate (ThDP)-dependent enzyme indolepyruvate decarboxylase (IPDC) is involved in the biosynthetic pathway of the phytohormone 3-indoleacetic acid and catalyzes the nonoxidative decarboxylation of 3-indolepyruvate to 3-indoleacetaldehyde and carbon dioxide. (PMID:15835904)¬† In addition, the enzyme was compared with the phenylpyruvate decarboxylase from Azospirillum brasilense and the indolepyruvate decarboxylase from Enterobacter cloacae. (PMID:21501384) Indole-3-pyruvate is a microbial metabolite, urinary indole-3-pyruvate is produced by Clostridium sporogenes (PMID:29168502) and Trypanasoma brucei (PMID:27856732).
Indomethacin is a non-steroidal antiinflammatory agent (NSAIA) with antiinflammatory, analgesic and antipyretic activity. Its pharmacological effect is thought to be mediated through inhibition of the enzyme cyclooxygenase (COX), the enzyme responsible for catalyzes the rate-limiting step in prostaglandin synthesis via the arachidonic acid pathway.
Indoxyl sulfate is a dietary protein metabolite and also a metabolite of the common amino acid tryptophan. It has been identified as a uremic toxin according to the European Uremic Toxin Working Group (PMID: 22626821). It is a circulating uremic toxin stimulating glomerular sclerosis and interstitial fibrosis. Indoxyl sulfate is one of the well-known substances of a group of protein-bound uremic retention solutes. Indoxyl sulfate increases the rate of progression of renal failure. In plasma, indoxyl sulfate is a protein-bound uremic solute that induces endothelial dysfunction by inhibiting endothelial proliferation and migration in vitro. Some studies suggest that indoxyl sulfate is also involved in oxidative stress. In hemodialyzed patients, serum levels of indoxyl sulfate are associated with levels of pentosidine, a marker of carbonyl and oxidative stress. In vitro, indoxyl sulfate increases reactive oxygen species (ROS) production in tubular cells and increases NAD(P)H oxidase activity in endothelial cells. Indoxyl sulfate impairs osteoblast function and induces abnormalities of bone turnover. Indoxyl sulfate strongly decreases the levels of glutathione, one of the most active antioxidant systems of the cell (PMID: 10681668 , 14681860 , 17471003 , 17403109). Indoxyl sulfate is a microbial metabolite found in Escherichia (PMID: 19946322).
Inosinic acid, also known as inosine monophosphate, IMP, 5'-inosinate or 5'-IMP, belongs to the class of organic compounds known as purine ribonucleoside monophosphates. These are nucleotides consisting of a purine base linked to a ribose to which one monophosphate group is attached. IMP is also classified as a nucleotide (a nucleoside monophosphate). Inosinic acid exists in all living species, ranging from bacteria to plants to humans. IMP is widely used as a flavor enhancer. In the food industry it is known as E number reference E630.  Inosinic acid can be converted into various salts including disodium inosinate (E631), dipotassium inosinate (E632), and calcium inosinate (E633). These three inosinate compounds are used as flavor enhancers for the basic taste umami. These inosinate salts are mostly used in soups, sauces, and seasonings for the intensification and balance of the flavor of meat. Inosinic acid is typically obtained from chicken byproducts or other meat industry waste. Inosinic acid or IMP is important in metabolism. It is the ribonucleotide of hypoxanthine and the first nucleotide formed during the synthesis of purine nucleotides. It can also be formed by the deamination of adenosine monophosphate by AMP deaminase.  GMP is formed by the inosinate oxidation to xanthylate (XMP). Within humans, inosinic acid participates in a number of enzymatic reactions. In particular, inosinic acid can be converted into phosphoribosyl formamidocarboxamide; which is catalyzed by the bifunctional purine biosynthesis protein. In addition, inosinic acid can be converted into xanthylic acid; which is catalyzed by the enzyme inosine-5'-monophosphate dehydrogenase 1.
Irbesartan is an angiotensin receptor blocker (ARB) used mainly for the treatment of hypertension. It competes with angiotensin II for binding at the AT1 receptor subtype. Unlike ACE inhibitors, ARBs do not have the adverse effect of dry cough. The use of ARBs is pending revision due to findings from several clinical trials suggesting that this class of drugs may be associated with a small increased risk of cancer.
Irinotecan is an antineoplastic enzyme inhibitor primarily used in the treatment of colorectal cancer. It is a derivative of camptothecin that inhibits the action of topoisomerase I. Irinotecan prevents religation of the DNA strand by binding to topoisomerase I-DNA complex, and causes double-strand DNA breakage and cell death.
(±)-erythro-Isoleucine is a flavouring ingredient, dietary supplement, and a nutrient. Branched-chain amino acids (BCAA) are essential amino acids whose carbon structure is marked by a branch point. These three amino acids are critical to human life and are particularly involved in stress, energy and muscle metabolism. BCAA supplementation as therapy, both oral and intravenous, in human health and disease holds great promise. BCAA denotes valine, isoleucine, and leucine which are branched chain essential amino acids. Despite their structural similarities, the branched amino acids have different metabolic routes, with valine going solely to carbohydrates, leucine solely to fats, and isoleucine to both. The different metabolism accounts for different requirements for these essential amino acids in humans: 12 mg/kg, 14 mg/kg, and 16 mg/kg of valine, leucine, and isoleucine respectively. Furthermore, these amino acids have different deficiency symptoms. Valine deficiency is marked by neurological defects in the brain, while isoleucine deficiency is marked by muscle tremors. BCAA are decreased in patients with liver disease such as hepatitis, hepatic coma, cirrhosis, extrahepatic biliary atresia, or portacaval shunt. Aromatic amino acids (AAA)-tyrosine, tryptophan, and phenylalanine (as well as methionine) are increased in these conditions. Valine, in particular, has been established as a useful supplemental therapy to the ailing liver. All the BCAA probably compete with AAA for absorption into the brain. Supplemental BCAA with vitamin B6 and zinc help normalize the BCAA:AAA ratio. The BCAA are not without side effects. Leucine alone, for example, exacerbates pellagra and can cause psychosis in pellagra patients by increasing excretion of niacin in the urine. Leucine may lower brain serotonin and dopamine. The ratio of leucine to other BCAA is greatest in pork, where leucine is 7 to 8 g and the other BCAA together are only 3 to 4 g (http://www.dcnutrition.com).
Isoquercitrin is found in alcoholic beverages. Isoquercitrin occurs widely in plants. Isoquercitrin is present in red wine.Isoquercitin can be isolated from mangoes and from Rheum nobile, the Noble rhubarb or Sikkim rhubarb, a giant herbaceous plant native to the Himalaya. Quercetin glycosides are also present in tea. (Wikipedia
Isorhamnetin 3-beta-d-glucoside, also known as isorhamnetin-3-glu, is a member of the class of compounds known as flavonoid-3-o-glycosides. Flavonoid-3-o-glycosides are phenolic compounds containing a flavonoid moiety which is O-glycosidically linked to carbohydrate moiety at the C3-position. Isorhamnetin 3-beta-d-glucoside is slightly soluble (in water) and a very weakly acidic compound (based on its pKa). Isorhamnetin 3-beta-d-glucoside can be synthesized from beta-D-glucose. Isorhamnetin 3-beta-d-glucoside can also be synthesized into isorhamnetin. Isorhamnetin 3-beta-d-glucoside can be found in sea-buckthornberry, which makes isorhamnetin 3-beta-d-glucoside a potential biomarker for the consumption of this food product. Isorhamnetin 3-beta-d-glucoside may be a unique S.cerevisiae (yeast) metabolite.
Isorhamnetin is the methylated metabolite of quercetin. Quercetin is an important dietary flavonoid with in vitro antioxidant activity. However, it is found in human plasma as conjugates with glucuronic acid, sulfate or methyl groups, with no significant amounts of free quercetin present. Isorhamnetin prevents endothelial cell injuries from oxidized LDL via inhibition of lectin-like ox-LDL receptor-1 upregulation, interference of ox-LDL-mediated intracellular signaling pathway (p38MAPK activation, NF-kappaB nuclear translocation, eNOS expression) and the antioxidant activity of isorhamnetin. Isorhamnetin prevents endothelial dysfunction, superoxide production, and overexpression of p47phox induced by angiotensin II. Isorhamnetin appears to be a potent drug against esophageal cancer due to its in vitro potential to not only inhibit proliferation but also induce apoptosis of Eca-109 cells. (PMID: 15493462, 17368593, 17374653, 16963021).
Isoxanthopterin is a pteridine normally present in plasma, urine, and other bodily fluids also vary from normal concentrations in some disease states and also have diagnostic value. Pteridines' urinary concentrations seem to vary independently from each other and from normal values to yield a pattern of excreted pteridines that is diagnostic for different species, tissues, and tumor types. Intravenous or intramuscular administration of isoxanthopterin inhibits the growth rates of animal tumor models. Pteridin derivatives are a family of organic compound with very similar chemical structures which play an important biochemistry role. Pteridines metabolism and its regulation in normal and pathological conditions have not been extensively investigated due to the difficulty of their quantification. A significant decrease of isoxanthopterin has been determined in cancer patients. (PMID 15837549, 9800651). Xanthine dehydrogenase (XDH) is the enzymes responsible for the conversion of xanthine to uric acid. It requires the presence of the molybdenum cofactor for its proper functioning. XDH is reported to have additional functions, i.e., the conversion of pterin to isoxanthopterin, one of the steps the degradation pathway of 5,6,7,8-tetrahydrobiopterin (BH4). Isoxanthopterin is very low in some cases of hereditary xanthinuria (OMIM 278300) and molybdenum cofactor deficiency (OMIM 252150). (PMID: 8812740).