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An aromatic amino acid that is alanine in which one of the methyl hydrogens is substituted by a phenyl group." []

Phenylalanine (Phe), also known as L-phenylalanine 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-phenylalanine is one of 20 proteinogenic amino acids, i.e., the amino acids used in the biosynthesis of proteins. Phenylalanine is found in all organisms ranging from bacteria to plants to animals. It is classified as an aromatic, non-polar amino acid. In humans, phenylalanine is an essential amino acid and the precursor of the amino acid tyrosine. Like tyrosine, phenylalanine is also a precursor for catecholamines including tyramine, dopamine, epinephrine, and norepinephrine. Catecholamines are neurotransmitters that act as adrenalin-like substances. Interestingly, several psychotropic drugs (mescaline, morphine, codeine, and papaverine) also have phenylalanine as a constituent. Phenylalanine is highly concentrated in the human brain and plasma. Normal metabolism of phenylalanine requires biopterin, iron, niacin, vitamin B6, copper, and vitamin C. An average adult ingests 5 g of phenylalanine per day and may optimally need up to 8 g daily. Phenylalanine is highly concentrated in a number of high protein foods, such as meat, cottage cheese, and wheat germ. An additional dietary source of phenylalanine is artificial sweeteners containing aspartame (a methyl ester of the aspartic acid/phenylalanine dipeptide). As a general rule, aspartame should be avoided by phenylketonurics and pregnant women. When present in sufficiently high levels, phenylalanine can act as a neurotoxin and a metabotoxin. A neurotoxin is a compound that disrupts or attacks neural cells and neural tissue. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Chronically high levels of phenylalanine are associated with at least five inborn errors of metabolism, including Hartnup disorder, hyperphenylalaninemia due to guanosine triphosphate cyclohydrolase deficiency, phenylketonuria (PKU), tyrosinemia type 2 (or Richner-Hanhart syndrome), and tyrosinemia type III (TYRO3). Phenylketonurics have elevated serum plasma levels of phenylalanine up to 400 times normal. High plasma concentrations of phenylalanine influence the blood-brain barrier transport of large neutral amino acids. The high plasma phenylalanine concentrations increase phenylalanine entry into the brain and restrict the entry of other large neutral amino acids (PMID: 19191004). Phenylalanine has been found to interfere with different cerebral enzyme systems. Untreated phenylketonuria (PKU) can lead to intellectual disability, seizures, behavioural problems, and mental disorders. It may also result in a musty smell and lighter skin. Classic PKU dramatically affects myelination and white matter tracts in untreated infants; this may be one major cause of neurological disorders associated with phenylketonuria. Mild phenylketonuria can act as an unsuspected cause of hyperactivity, learning problems, and other developmental problems in children. It has been recently suggested that PKU may resemble amyloid diseases, such as Alzheimer's disease and Parkinson's disease, due to the formation of toxic amyloid-like assemblies of phenylalanine (PMID: 22706200). Phenylalanine also has some potential benefits. Phenylalanine can act as an effective pain reliever. Its use in premenstrual syndrome and Parkinson's may enhance the effects of acupuncture and electric transcutaneous nerve stimulation (TENS). Phenylalanine and tyrosine, like L-DOPA, produce a catecholamine-like effect. Phenylalanine is better absorbed than tyrosine and may cause fewer headaches. Low phenylalanine diets have been prescribed for certain cancers with mixed results. For instance, some tumours use more phenylalanine than others (particularly melatonin-producing tumours called melanomas).

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.

Benzocaine is a surface anesthetic that acts by preventing transmission of impulses along nerve fibers and at nerve endings. Benzocaine is a local anesthetic commonly used as a topical pain reliever. It is the active ingredient in many over-the-counter analgesic ointments. Benzocaine is an ester, a compound made from the organic acid PABA (para-aminobenzoic acid) and ethanol. The process in which this ester is created is known as Fischer esterification.

The D-enantiomer of phenylalanine." []

A benzoate ester that is the ethyl ester of 3-aminobenzoic acid. Used (in the form of its methanesulfonate salt) as an anaesthetic for fish." []

Dimethylaniline-N-oxide is a substrate for Dimethylaniline monooxygenase 4, Dimethylaniline monooxygenase 3, Dimethylaniline monooxygenase 1, Dimethylaniline monooxygenase 5, Putative dimethylaniline monooxygenase 6 and Dimethylaniline monooxygenase 2.

Indoline is a member of indoles.

4-Hydroxy-2,6-dimethylaniline is a metabolite of lidocaine. Lidocaine, Xylocaine, or lignocaine is a common local anesthetic and antiarrhythmic drug. Lidocaine is used topically to relieve itching, burning and pain from skin inflammations, injected as a dental anesthetic or as a local anesthetic for minor surgery. (Wikipedia)

N-Acetyl-L-methionine or N-Acetylmethionine, belongs to the class of organic compounds known as N-acyl-alpha amino acids. N-acyl-alpha amino acids are compounds containing an alpha amino acid which bears an acyl group at its terminal nitrogen atom. N-Acetylmethionine can also be classified as an alpha amino acid or a derivatized alpha amino acid. Technically, N-Acetylmethionine is a biologically available N-terminal capped form of the proteinogenic alpha amino acid L-methionine. N-acetyl amino acids can be produced either via direct synthesis of specific N-acetyltransferases or via the proteolytic degradation of N-acetylated proteins by specific hydrolases. N-terminal acetylation of proteins is a widespread and highly conserved process in eukaryotes that is involved in protection and stability of proteins (PMID: 16465618). About 85% of all human proteins and 68% of all yeast proteins are acetylated at their N-terminus (PMID: 21750686). Several proteins from prokaryotes and archaea are also modified by N-terminal acetylation. The majority of eukaryotic N-terminal-acetylation reactions occur through N-acetyltransferase enzymes or NAT’s (PMID: 30054468). These enzymes consist of three main oligomeric complexes NatA, NatB, and NatC, which are composed of at least a unique catalytic subunit and one unique ribosomal anchor. The substrate specificities of different NAT enzymes are mainly determined by the identities of the first two N-terminal residues of the target protein. The human NatA complex co-translationally acetylates N-termini that bear a small amino acid (A, S, T, C, and occasionally V and G) (PMID: 30054468). NatA also exists in a monomeric state and can post-translationally acetylate acidic N-termini residues (D-, E-). NatB and NatC acetylate N-terminal methionine with further specificity determined by the identity of the second amino acid. N-acetylated amino acids, such as N-acetylmethionine can be released by an N-acylpeptide hydrolase from peptides generated by proteolytic degradation (PMID: 16465618). In addition to the NAT enzymes and protein-based acetylation, N-acetylation of free methionine can also occur. In particular, N-Acetylmethionine can be biosynthesized from L-methionine and acetyl-CoA by the enzyme methionine N-acetyltransferase (EC 2.3.1.66). Excessive amounts N-acetyl amino acids including N-acetylmethionine (as well as N-acetylglycine, N-acetylserine, N-acetylglutamine, N-acetylglutamate, N-acetylalanine, N-acetylleucine and smaller amounts of N-acetylthreonine, N-acetylisoleucine, and N-acetylvaline) can be detected in the urine with individuals with acylase I deficiency, a genetic disorder (PMID: 16465618). Aminoacylase I is a soluble homodimeric zinc binding enzyme that catalyzes the formation of free aliphatic amino acids from N-acetylated precursors. In humans, Aminoacylase I is encoded by the aminoacylase 1 gene (ACY1) on chromosome 3p21 that consists of 15 exons (OMIM 609924). Individuals with aminoacylase I deficiency will experience convulsions, hearing loss and difficulty feeding (PMID: 16465618). ACY1 can also catalyze the reverse reaction, the synthesis of acetylated amino acids. Many N-acetylamino acids, including N-acetylmethionine are classified as uremic toxins if present in high abundance in the serum or plasma (PMID: 26317986; PMID: 20613759). Uremic toxins are a diverse group of endogenously produced molecules that, if not properly cleared or eliminated by the kidneys, can cause kidney damage, cardiovascular disease and neurological deficits (PMID: 18287557).

1,2,3,4,5,6-Hexahydro-7H-cyclopenta[b]pyridin-7-one is found in alcoholic beverages. Proline-derived Maillard product. 1,2,3,4,5,6-Hexahydro-7H-cyclopenta[b]pyridin-7-one is a constituent of wort and beer. 1,2,3,4,5,6-Hexahydro-7H-cyclopenta[b]pyridin-7-one is a flavouring ingredient.

A racemate comprising equimolar amounts of N-acetyl-L-methionine and N-acetyl-D-methionine." []

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.

Valylproline is a dipeptide composed of valine and proline. It is an incomplete breakdown product of protein digestion or protein catabolism. Dipeptides are organic compounds containing a sequence of exactly two alpha-amino acids joined by a peptide bond. 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.

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.

A polyene that is tridecane carrying trans double bonds at positions 2, 8, and 10 and triple bonds at positions 4 and 6. It is a phytotoxin isolated from the plant, Aethusa cynapium." []

Epinephrine is a catecholamine, a sympathomimetic monoamine derived from the amino acids phenylalanine and tyrosine. It is the active sympathomimetic hormone secreted from the adrenal medulla in most species. It stimulates both the alpha- and beta- adrenergic systems, causes systemic vasoconstriction and gastrointestinal relaxation, stimulates the heart, and dilates bronchi and cerebral vessels. It is used in asthma and cardiac failure and to delay absorption of local anesthetics. Epinephrine also constricts arterioles in the skin and gut while dilating arterioles in leg muscles. It elevates the blood sugar level by increasing hydrolysis of glycogen to glucose in the liver, and at the same time begins the breakdown of lipids in adipocytes. Epinephrine has a suppressive effect on the immune system.

Arene oxide is an epoxide.

Normetanephrine, also known as normetadrenaline or N111, 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. Normetanephrine is a solid that is soluble in water. Normetanephrine is a metabolite of norepinephrine created by action of catechol-O-methyl transferase on norepinephrine. Within humans, normetanephrine participates in a number of enzymatic reactions. In particular, normetanephrine can be converted into 3-methoxy-4-hydroxyphenylglycolaldehyde through its interaction with the enzyme amine oxidase [flavin-containing] A. It is also involved in the metabolic disorder called transient tyrosinemia of the newborn. This compound is excreted in the urine and is found in certain tissues. It is a marker for catecholamine-secreting tumors such as pheochromocytoma (PMID: 30538672).

Glutamylisoleucine is a dipeptide composed of glutamate and isoleucine, 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. Glutamylisoleucine 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.

Dimethyl maleate belongs to the class of organic compounds known as fatty acid esters. These are carboxylic ester derivatives of a fatty acid. Dimethyl maleate is the methyl ester of maleic acid and the cis-isomer of dimethyl fumarate. Dimethyl maleate is a commonly used thiol-alkylating agent and enjoys widespread use in many organic synthesis (e.g. as a dienophile for diene syntheses). In the production of plastics, pigments, pharmaceuticals, and agricultural products, dimethyl maleate is used as an additive and an intermediate. In the production of paints, adhesives, and copolymers, dimethyl maleate is used as an intermediate.

L-Lathyrine is a non-proteinogenic L-alpha-amino acid. Lathyrine is a natural product found in Lathyrus tingitanus and Euglena gracilis with data available.

Folic acid or folate, is a vitamin that belongs to the class of compounds known as pterins. Chemically, folate consists of three distinct chemical moieties linked together. A pterin (2-amino-4-hydroxy-pteridine) linked by a methylene bridge to a p-aminobenzoyl group that in turn is linked through an amide linkage to glutamic acid. It is a member of the vitamin B family and is primarily known as vitamin B9. Folate is required for the body to make DNA and RNA and metabolize amino acids necessary for cell division for the hematopoietic system. As humans cannot make folate, it is required in the diet, making it an essential nutrient (i.e. a vitamin). Folate occurs naturally in many foods including mushrooms, spinach, yeast, green leaves, and grasses (poaceae). Folic acid, being biochemically inactive, is converted to tetrahydrofolic acid and methyltetrahydrofolate by the enzyme known as dihydrofolate reductase. Tetrahydrofolate and methyltetrahydrofolate are transported across cells by receptor-mediated endocytosis where they are needed to maintain normal erythropoiesis, synthesize purine and thymidylate nucleic acids, interconvert amino acids and generate formic acid. Folic acid is used in the treatment and prevention of folate deficiencies and megaloblastic anemia. Folic acid is also used as a supplement by women during pregnancy to reduce the risk of neural tube defects (NTDs) in babies. Low levels in early pregnancy are believed to be the cause of more than half of babies born with NTDs (PMID: 28097362). Folic acid is also a microbial metabolite produced by Bifidobacterium and Lactobacillus (PMID: 22254078).

Trans-1,2-Dihydrobenzene-1,2-diol is an intermediate in the metabolism of Prostaglandin and leukotriene. It is a substrate for Aldo-keto reductase family 1 member C3, Aldo-keto reductase family 1 member C4, Aldo-keto reductase family 1 member C2 and Aldo-keto reductase family 1 member C1.