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Phenylalanine is an essential alpha-amino acid. It exists in two forms, a D and an L form, which are enantiomers (mirror-image molecules) of each other. It has a benzyl side chain and its name comes from its chemical structures that consists of a phenyl group substituted for one of the hydrogens in the side chain of alanine. Because of its phenyl group, phenylalanine is an aromatic compound that at room temperature exists as a white, powdery solid. L -phenylalanine (LPA) is an electrically-neutral amino acid and its enantiomer, D -phenylalanine (DPA), can be synthesized artificially. L -phenylalanine can also be converted into L -tyrosine, another one of the twenty protein-forming amino acids. Copyright Text is available under the Creative Commons Attribution/Share-Alike License. See for details. Source: Wikipedia, Phenylalanine (Wikipedia)

An essential aromatic amino acid that is a precursor of melanin, dopamine, noradrenalin (norepinephrine), and thyroxine. Source: National Library of Medicine, MeSH 2006

Phenylalanine and the elevation of one or more organic acids is diagnostic for organic aciduria. This alpha-amino acid is a bacterial metabolite of tyrosine. Elevated levels may be seen with tyrosinemia, PKU, and hawkinsinuria.(Information from: Kumps A, Duez P, Mardens Y. Metabolic, Nutritional, Iatrogenic, and Artifactual Sources of Urinary Organic Acids: A Comprehensive Table. Clinical Chemistry 2002;48:708-717.) Source: Regenstrief LOINC

Phenylalanine is a primary marker for phenylketonuria and hyperphenylalaninemia (variant, benign), two disorders of biopterin biosynthesis and regeneration. Source: Regenstrief LOINC

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Language Variants Get Info

Tag Language Translation
zh-CN Chinese (China) 苯丙氨酸
Synonyms: Phe
fr-CA French (Canada) Phénylalanine
et-EE Estonian (Estonia) fenüülalaniin
es-ES Spanish (Spain) Fenilalanina
it-IT Italian (Italy) Fenilalanina
tr-TR Turkish (Turkey) Fenilalanin
ru-RU Russian (Russian Federation) Фенилаланин
nl-NL Dutch (Netherlands) fenylalanine
Synonyms: phenylalanine
fr-BE French (Belgium) Phénylalanine
pl-PL Polish (Poland) Fenyloalanina