phenylalanine

American  

[fen-l-al-uh-neen, -nin, feen-] / ˌfɛn lˈæl əˌnin, -nɪn, ˌfin- /

noun

Biochemistry.

1. a crystalline, water-soluble, essential amino acid, C 6 H 5 CH 2 CH(NH2 )COOH, necessary to the nutrition of humans and most animals, obtained chiefly from egg white or skim milk. Phe; F

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phenylalanine British  

/ ˌfiːnaɪlˈæləˌniːn, ˌfɛnɪl- /

noun

1. an aromatic essential amino acid; a component of proteins

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phenylalanine Scientific  

/ fĕn′əl-ăl′ə-nēn′ /

1. An essential amino acid. Chemical formula: C ₉ H ₁₁ NO ₂ .

2. See more at amino acid

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Etymology

Origin of phenylalanine

First recorded in 1880–85; phenyl + alanine

Example Sentences

Led by Jie V. Zhao, Yitang Sun, Junmeng Zhang, and Kaixiong Ye from the University of Hong Kong and the University of Georgia, the research team focused on phenylalanine and tyrosine.

From Science Daily • Feb. 26, 2026

They used both observational data and genetic techniques to assess whether blood levels of phenylalanine and tyrosine were related to overall mortality and predicted lifespan.

From Science Daily • Feb. 26, 2026

However, for individuals with a rare genetic disorder called phenylketonuria, phenylalanine can accumulate and cause health issues, so they are sometimes instructed to avoid it.

From Salon • Jul. 14, 2023

The WHO reports show that aspartame itself is rapidly broken down in the gut into three other substances - phenylalanine, aspartic acid and methanol.

From BBC • Jul. 13, 2023

The amino acid phenylalanine is attached to the other end of the tRNA.

From Textbooks • Jun. 9, 2022