Main Entry: phe·nyl·al·a·nine

Pronunciation: \ˌfen-^əl-ˈal-ə-ˌnēn, ˌfēn-\

Function: noun

: an essential amino acid C₉H₁₁NO₂ that is obtained in its levorotatory L-form by the hydrolysis of proteins (as lactalbumin), that is essential in human nutrition, and that is converted in the normal body to tyrosine—abbreviation Phe; see phenylketonuria, phenylpyruvic acid