4-[4-[(2S)-2-amino-3-hydroxy-3-oxopropyl]-3H-imidazol-2-yl]-2-methylaminobutanoic acid
4-[4-[(2S)-2-amino-3-hydroxy-3-oxo-propyl]-3H-imidazol-2-yl]-2-methylamino-butanoic acid
4-[4-[(2S)-2-amino-3-hydroxy-3-keto-propyl]-3H-imidazol-2-yl]-2-methylamino-butyric acid