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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).

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." []

Ethyl 2-aminobenzoate is found in citrus. Ethyl 2-aminobenzoate is a flavouring ingredient. Ethyl 2-aminobenzoate is present in orange juice, orange peel and concord grape.

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.

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).

7-Methylguanine is a metabolite of DNA methylation and depurination observed in normal human biofluids; however, it has been found significantly higher in the urine of smokers than in nonsmokers. (PMID 16059882). 7-Methylguanine has been identified in the human placenta (PMID: 32033212).

Treatment of Tuberculosis and leprosy Metabolite of Protionamide Dollery, Colin Therapeutic Drugs, 2nd Ed. 1999 p. P270

1-Methylguanine is a naturally occurring modified purine derived from tRNA, found in elevated levels in the serum and urine of cancer patients (PMID:2413515). Increase of 1-methylguanine in the urine of colorectal tumor bearing patients, has been justified either by a more rapid turnover of nucleic acids in tumor tissue or by an increase in the extent of their methylation (PMID:9069642).

3-Methylguanine is a methylated purine base. Methylated purine bases are known to be present in normal urine and to change under pathological conditions, in particular in the development of leukemia, tumors and immunodeficiency, by the altered turnover of nucleic acids typical of these diseases. (PMID 9069642).

phenyl-Alanine is a natural product found in Cyperus aromaticus, Taraxacum formosanum, and other organisms with data available.

5-Pyridoxolactone is a normal human metabolite of vitamin B6 metabolism. (PMIDs 9211301, 14995036).

Ephedrine is only found in individuals who have consumed this drug. Ephedrine is an alpha- and beta-adrenergic agonist that may also enhance release of norepinephrine. It has been used in the treatment of several disorders including asthma, heart failure, rhinitis, and urinary incontinence, and for its central nervous system stimulatory effects in the treatment of narcolepsy and depression. It has become less extensively used with the advent of more selective agonists. [PubChem] Ephedrine is similar in molecular structure to the well-known drugs phenylpropanolamine and methamphetamine, as well as to the important neurotransmitter epinephrine (adrenalin). Chemically, it is an alkaloid with a phenethylamine skeleton found in various plants in the genus Ephedra (family Ephedraceae). It works mainly by increasing the activity of norepinephrine (noradrenalin) on adrenergic receptors. It is most usually marketed as the hydrochloride or sulfate salt.

5-(3-Pyridyl)-2-hydroxytetrahydrofuran is classified as a pyridine or a Pyridine derivative. Pyridines are compounds containing a pyridine ring, which is a six-member aromatic heterocycle which consists of one nitrogen atom and five carbon atoms. 5-(3-Pyridyl)-2-hydroxytetrahydrofuran is considered to be soluble (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.

A methylguanine in which the methyl group is positioned on the oxygen at position 6. Formed in DNA by alkylation of the oxygen atom of guanine, most often by N-nitroso compounds and sometimes due to methylation by other compounds such as endogenous S-adenosylmethionine, it base-pairs to thymine rather than cytidine, causing a G:C to A:T transition in DNA." []

An amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of L-phenylalanine; major species at pH 7.3." []

A D-alpha-amino acid zwitterion that is D-phenylalanine in which a proton has been transferred from the carboxy group to the amino group. It is the major species at pH 7.3." []

(R)-2-Hydroxy-2H-1,4-benzoxazin-3(4H)-one is found in cereals and cereal products. (R)-2-Hydroxy-2H-1,4-benzoxazin-3(4H)-one is a constituent of juvenile wheat (Triticum aestivum).

6-O-methylguanine is a methylguanine in which the methyl group is positioned on the oxygen at position 6. Formed in DNA by alkylation of the oxygen atom of guanine, most often by N-nitroso compounds and sometimes due to methylation by other compounds such as endogenous S-adenosylmethionine, it base-pairs to thymine rather than cytidine, causing a G:C to A:T transition in DNA. It has a role as a mutagen.

L-tyrosinal is an amino aldehyde that is L-tyrosine in which the carboxy group has undergone formal redution to give the corrresponding aldehyde It is an amino aldehyde, a member of phenols and a primary amino compound. It is a conjugate base of a L-tyrosinal(1+).

A member of the class of acetophenones that is acetophenone substituted at the para-position by a nitro group." []

2-ethoxybenzamide appears as white or almost-white crystalline powder. Almost odorless. Tasteless. (NTP, 1992) Ethenzamide is an organic molecular entity.

Racephedrine is a natural product found in Ephedra distachya with data available.