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

The paper, titled "The role of phenylalanine and tyrosine in longevity: a cohort and Mendelian randomization study," examined whether levels of these nutrients in the blood are connected to lifespan.

From Science Daily • Feb. 26, 2026

People with PKU cannot break down phenylalanine, an amino acid found in protein foods.

From BBC • Jan. 1, 2024

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

This molecule disrupts the synthesis of phenylalanine, tyrosine, and tryptophan.

From Textbooks • Jun. 9, 2022