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2-amino-3-(4-chlorophenyl)propanoic acid is a phenylalanine derivative. A selective and irreversible inhibitor of tryptophan hydroxylase, a rate-limiting enzyme in the biosynthesis of serotonin (5-HYDROXYTRYPTAMINE). Fenclonine acts pharmacologically to deplete endogenous levels of serotonin.

Caffeine is a methyl xanthine alkaloid that is also classified as a purine. Formally, caffeine 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. Caffeine is chemically related to the adenine and guanine bases of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). It is found in the seeds, nuts, or leaves of a number of plants native to Africa, East Asia and South America and helps to protect them against predator insects and to prevent germination of nearby seeds. The most well-known source of caffeine is the coffee bean. Caffeine is the most widely consumed psychostimulant drug in the world. 85% of American adults consumed some form of caffeine daily, consuming 164 mg on average. Caffeine is mostly is consumed in the form of coffee. Caffeine is a central nervous system stimulant that reduces fatigue and drowsiness. At normal doses, caffeine has variable effects on learning and memory, but it generally improves reaction time, wakefulness, concentration, and motor coordination. Caffeine is a proven ergogenic aid in humans. Caffeine improves athletic performance in aerobic (especially endurance sports) and anaerobic conditions. Moderate doses of caffeine (around 5 mg/kg) can improve sprint performance, cycling and running time trial performance, endurance and cycling power output (PMID: 32551869). At intake levels associated with coffee consumption, caffeine appears to exert most of its biological effects through the antagonism of the A1 and A2A subtypes of the adenosine receptor. Adenosine is an endogenous neuromodulator with mostly inhibitory effects, and adenosine antagonism by caffeine results in effects that are generally stimulatory. Some physiological effects associated with caffeine administration include central nervous system stimulation, acute elevation of blood pressure, increased metabolic rate, and diuresis. A number of in vitro and in vivo studies have demonstrated that caffeine modulates both innate and adaptive immune responses. For instance, studies indicate that caffeine and its major metabolite paraxanthine suppress neutrophil and monocyte chemotaxis, and also suppress production of the pro-inflammatory cytokine tumor necrosis factor (TNF) alpha from human blood. Caffeine has also been reported to suppress human lymphocyte function as indicated by reduced T-cell proliferation and impaired production of Th1 (interleukin [IL]-2 and interferon [IFN]-gamma), Th2 (IL-4, IL-5) and Th3 (IL-10) cytokines. Studies also indicate that caffeine suppresses antibody production. The evidence suggests that at least some of the immunomodulatory actions of caffeine are mediated via inhibition of cyclic adenosine monophosphate (cAMP)-phosphodiesterase (PDE), and consequential increase in intracellular cAMP concentrations. Overall, these studies indicate that caffeine, like other members of the methylxanthine family, is largely anti-inflammatory in nature, and based on the pharmacokinetics of caffeine, many of its immunomodulatory effects occur at concentrations that are relevant to normal human consumption. (PMID: 16540173). Caffeine is rapidly and almost completely absorbed in the stomach and small intestine and distributed to all tissues, including the brain. Caffeine metabolism occurs primarily in the liver, where the activity of the cytochrome P450 isoform CYP1A2 accounts for almost 95% of the primary metabolism of caffeine. CYP1A2-catalyzed 3-demethylation of caffeine results in the formation of 1,7-dimethylxanthine (paraxanthine). Paraxanthine may be demethylated by CYP1A2 to form 1-methylxanthine, which may be oxidized to 1-methyluric acid by xanthine oxidase. Paraxanthine may also be hydroxylated by CYP2A6 to form 1,7-dimethyluric acid, or acetylated by N-acetyltransferase 2 (NAT2) to form 5-acetylamino-6-formylamino-3-methyluracil, an unstable compound that may be deformylated nonenzymatically to form 5-acetylamino-6-amino-3-methyluracil. Caffeine concentrations in coffee beverages can be quite variable. A standard cup of coffee is often assumed to provide 100 mg of caffeine, but a recent analysis of 14 different specialty coffees purchased at coffee shops in the US found that the amount of caffeine in 8 oz (=240 ml) of brewed coffee ranged from 72 to 130 mg. Caffeine in espresso coffees ranged from 58 to 76 mg in a single shot. (PMID: 16507475).

Tryptophan (Trp) or L-tryptophan 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). Amino acids are organic compounds that contain amino (–NH2) and carboxyl (–COOH) functional groups, along with a side chain (R group) specific to each amino acid. L-tryptophan is one of 20 proteinogenic amino acids, i.e., the amino acids used in the biosynthesis of proteins. Tryptophan is found in all organisms ranging from bacteria to plants to animals. It is classified as a non-polar, uncharged (at physiological pH) aromatic amino acid. Tryptophan is an essential amino acid, meaning the body cannot synthesize it, and it must be obtained from the diet. The requirement for tryptophan and protein decreases with age. The minimum daily requirement for adults is 3 mg/kg/day or about 200 mg a day. There is 400 mg of tryptophan in a cup of wheat germ. A cup of low-fat cottage cheese contains 300 mg of tryptophan and chicken and turkey contain up to 600 mg of tryptophan per pound (http://www.dcnutrition.com). Tryptophan is particularly plentiful in chocolate, oats, dried dates, milk, yogurt, cottage cheese, red meat, eggs, fish, poultry, sesame, chickpeas, almonds, sunflower seeds, pumpkin seeds, buckwheat, spirulina, and peanuts. Tryptophan is the precursor of both serotonin and melatonin. Melatonin is a hormone that is produced by the pineal gland in animals, which regulates sleep and wakefulness. Serotonin is a brain neurotransmitter, platelet clotting factor, and neurohormone found in organs throughout the body. Metabolism of tryptophan into serotonin requires nutrients such as vitamin B6, niacin, and glutathione. Niacin (also known as vitamin B3) is an important metabolite of tryptophan. It is synthesized via kynurenine and quinolinic acids, which are products of tryptophan degradation. There are a number of conditions or diseases that are characterized by tryptophan deficiencies. For instance, fructose malabsorption causes improper absorption of tryptophan in the intestine, which reduces levels of tryptophan in the blood and leads to depression. High corn diets or other tryptophan-deficient diets can cause pellagra, which is a niacin-tryptophan deficiency disease with symptoms of dermatitis, diarrhea, and dementia. Hartnup's disease is a disorder in which tryptophan and other amino acids are not absorbed properly. Symptoms of Hartnup's disease include skin rashes, difficulty coordinating movements (cerebellar ataxia), and psychiatric symptoms such as depression or psychosis. Tryptophan supplements may be useful for treating Hartnup's disease. Assessment of tryptophan deficiency is done through studying excretion of tryptophan metabolites in the urine or blood. Blood may be the most sensitive test because the amino acid tryptophan is transported in a unique way. Increased urination of tryptophan breakdown products (such as kynurenine) correlates with increased tryptophan degradation, which occurs with oral contraception, depression, mental retardation, hypertension, and anxiety states. Tryptophan plays a role in "feast-induced" drowsiness. Ingestion of a meal rich in carbohydrates triggers the release of insulin. Insulin, in turn, stimulates the uptake of large neutral branched-chain amino acids (BCAAs) into muscle, increasing the ratio of tryptophan to BCAA in the bloodstream. The increased tryptophan ratio reduces competition at the large neutral amino acid transporter (which transports both BCAAs and tryptophan), resulting in greater uptake of tryptophan across the blood-brain barrier into the cerebrospinal fluid (CSF). Once in the CSF, tryptophan is converted into serotonin and the resulting serotonin is further metabolized into melatonin by the pineal gland, which promotes sleep. Because tryptophan is converted into 5-hydroxytryptophan (5-HTP) which is then converted into the neurotransmitter serotonin, it has been proposed that consumption of tryptophan or 5-HTP may improve depression symptoms by increasing the level of serotonin in the brain. Tryptophan is sold over the counter in the United States (after being banned to varying extents between 1989 and 2005) and the United Kingdom as a dietary supplement for use as an antidepressant, anxiolytic, and sleep aid. It is also marketed as a prescription drug in some European countries for the treatment of major depression. There is evidence that blood tryptophan levels are unlikely to be altered by changing the diet, but consuming purified tryptophan increases the serotonin level in the brain, whereas eating foods containing tryptophan does not. This is because the transport system that brings tryptophan across the blood–brain barrier also transports other amino acids which are contained in protein food sources. Under certain situations, tryptophan can be a neurotoxin and a metabotoxin. A neurotoxin is a compound that causes damage to the brain and nerve tissues. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Chronically high levels of tryptophan can be found in glutaric aciduria type I (glutaric acidemia type I or GA1). 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. 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. High levels of tryptophan have also been implicated in eosinophilia-myalgia syndrome (EMS), an incurable and sometimes fatal flu-like neurological condition linked to the ingestion of large amounts of L-tryptophan. The risk of developing EMS increases with larger doses of tryptophan and increasing age. Some research suggests that certain genetic polymorphisms may be related to the development of EMS. The presence of eosinophilia is a core feature of EMS, along with unusually severe myalgia (muscle pain). It is thought that both tryptophan and certain unidentified tryptophan contaminants may contribute to EMS (PMID: 1763543 ). It has also been suggested that excessive tryptophan or elevation of its metabolites could play a role in amplifying some of the pathological features of EMS (PMID: 10721094 ). This pathological damage is further augmented by metabolites of the kynurenine pathway (a tryptophan degradation pathway).

6-Chloro-N-(1-methylethyl)-1,3,5-triazine-2,4-diamine is a major soil metabolite of Atrazine DKW85-F. Environmental pollutant of soil and water.

Isocaffeine is a natural product found in Murraya paniculata with data available.

Indoleacrylic acid (CAS: 1204-06-4), also known as indoleacrylate, IA, and IAcrA, is a member of the class of compounds known as indoles. Indoles are compounds containing an indole moiety, which consists of pyrrole ring fused to benzene to form 2,3-benzopyrrole. Indoleacrylic acid is practically insoluble (in water) and a weak acidic compound (based on its pKa). Within the cell, indoleacrylic acid is primarily located in the membrane (predicted from logP). Indoleacrylic acid is best known as a plant growth hormone (a natural auxin), whereas its biological role in animals is still unknown. A two-stage production of this compound is likely: intestinal microorganisms catabolize tryptophan to indole derivatives which are then absorbed and converted into indoleacrylic acid and its glycine conjugate, indolylacryloylglycine (IAcrGly). Indolylacryloylglycine excretion in urine is especially pronounced in some myopathies, namely in boys with Duchenne muscular dystrophy (PMID: 10707769). It has been recently found that indoleacrylic acid promotes intestinal epithelial barrier function and mitigates inflammatory responses. Stimulating indoleacrylic acid production could promote anti-inflammatory responses and have therapeutic benefits (PMID: 28704649). Urinary Indole-3-acrylate is produced by Clostridium sporogenes (PMID: 29168502). Indoleacrylic acid is also a metabolite of Peptostreptococcus (PMID: 28704649, 29168502).

1,8-diazacyclotetradecane-2,9-dione is a ketone.

Methyl 1-methoxy-1H-indole-3-carboxylate is found in herbs and spices. Methyl 1-methoxy-1H-indole-3-carboxylate is produced by Japanese horseradish (Wasabia japonica).

A glycine derivative that is glycine with a tertiary butyl group at position 2." []

2-Aminoacetophenone is found in cereals and cereal products. 2-Aminoacetophenone is a component of tortilla aroma and of other corn flour product

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).

An alpha,beta-unsaturated monocarboxylic acid that is acrylic acid in which one of the hydrogens at position 3 is replaced by an indol-2-yl group." []

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).

3'-Deoxythymidine is a natural product found in Petrosiidae with data available.

Cyclo(L-leucyl-L-leucyl) is a member of the class of 2,5-diketopiperazines that is piperazine-2,5-dione in which one hydrogen at position 3 and one hydrogen at position 6 are replaced by isobutyl groups (the 3S,6S-diastereomer). Cyclo(L-leucyl-L-leucyl) is a natural product found in Bacillus subtilis and Kandelia candel with data available.

3,4-Dihydroxyphenylglycol, also known as DHPG or DOPEG, belongs to the class of organic compounds known as catechols. Catechols are compounds containing a 1,2-benzenediol moiety. 3,4-Dihydroxyphenylglycol is an extremely weak basic (essentially neutral) compound. 3,4-Dihydroxyphenylglycol exists in all living organisms, ranging from bacteria to plants to humans. It is a potent antioxidant (PMID: 30007612). In mammals, 3,4-Dihydroxyphenylglycol is the primary metabolite of norepinephrine and is generated through the action of the enzyme monoamine oxidase (MAO). DHPG is then further metabolized by the enzyme Catechol-O-methyltransferase (COMT) to 3-methoxy-4-hydroxyphenylglycol (MHPG). Within humans, 3,4-dihydroxyphenylglycol participates in a number of enzymatic reactions. In particular, 3,4-dihydroxyphenylglycol can be biosynthesized from 3,4-dihydroxymandelaldehyde; which is mediated by the enzyme alcohol dehydrogenase 1A. In addition, 3,4-dihydroxyphenylglycol and guaiacol can be converted into vanylglycol and pyrocatechol through its interaction with the enzyme catechol O-methyltransferase. Outside of the human body, 3,4-dihydroxyphenylglycol is found, on average, in the highest concentration in olives. High levels of DHPG (up to 368 mg/kg of dry weight) have been found in the pulp of natural black olives. This could make 3,4-dihydroxyphenylglycol a potential biomarker for the consumption of olives and olive oil. 3,4-Dihydroxyphenylglycol has been linked to Menkes disease (PMID: 19234788). DHPG level are lower in Menkes patients (3.57 ± 0.40 nM) than healthy infants 8.91 ± 0.77 nM). Menkes disease (also called “kinky hair disease”) is an X-linked recessive neurodevelopmental disorder caused by defects in a gene that encodes a copper-transporting ATPase (ATP7A). Affected infants typically appear healthy at birth and show normal neurodevelopment for 2-3 months. Subsequently there is loss of milestones (e.g., smiling, visual tracking, head control) and death in late infancy or childhood (PMID: 19234788).

1-Amino-4-ethynylbenzene http://www.sigmaaldrich.com/catalog/search/ProductDetail/FLUKA/46039

(R)-mandelic Acid, also known as (R)-2-Hydroxy-2-phenylacetic acid or (-)-(R)-Mandelate, is classified as a benzene or a Benzene derivative. Benzenes are aromatic compounds containing one monocyclic ring system consisting of benzene. (R)-mandelic Acid is considered to be soluble (in water) and acidic

Hexaethylene glycol belongs to the class of organic compounds known as polyethylene glycols. These are oligomers or polymers of ethylene oxide, with the general formula (C2H4O)n (with n>=3).

Carbidopa is only found in individuals that have used or taken this drug. It is an inhibitor of DOPA decarboxylase, preventing conversion of levodopa to dopamine. It is used in parkinson disease to reduce peripheral adverse effects of levodopa. It has no antiparkinson actions by itself. [PubChem]When mixed with levodopa, carbidopa inhibits the peripheral conversion of levodopa to dopamine and the decarboxylation of oxitriptan to serotonin by aromatic L-amino acid decarboxylase. This results in increased amount of levodopa and oxitriptan available for transport to the CNS. Carbidopa also inhibits the metabolism of levodopa in the GI tract, thus, increasing the bioavailability of levodopa.

3-hydroxy-2-methyl-[R-(R,S)]-butanoic acid

3-Hydroxy-2-methyl-[S-(R,R)]-butanoic acid

N-methylvaline, also known as MeVal, D-Valine, or N-Methyl-L-valine, is an N-methylamino acid that is the N-methyl derivative of valine. It functions as a bronsted acid, a molecular entity capable of donating a hydron to an acceptor (Bronsted base) via oxoacid