ChEBI: Phenylalanine is an aromatic amino acid that is alanine in which one of the methyl hydrogens is substituted by a phenyl group. It has a role as a Daphnia magna metabolite. It is an alpha-amino acid and an aromatic amino acid. It contains a benzyl group. It is a conjugate base of a phenylalaninium. It is a conjugate acid of a phenylalaninate.