The molecule is a non-proteinogenic L-alpha-amino acid that is L-phenylalanine in which one of the benzyl hydrogens is replaced by a methyl group (the 3S-stereoisomer). It derives from a L-phenylalanine. It is a tautomer of a (2S,3S)-beta-methylphenylalanine zwitterion.
(2S,3S)-2-amino-3-phenylbutanoic acid