(2S)-2-[[[(2S)-2-acetamido-3-phenylpropanoyl]amino]carbamoylamino]-3-methyl-N-(phenylmethyl)butanamide
(2S)-2-[[[(2S)-2-acetamido-3-phenyl-propanoyl]amino]carbamoylamino]-3-methyl-N-(phenylmethyl)butanamide
(2S)-2-[[[N'-[(2S)-2-acetamido-1-oxo-3-phenylpropyl]hydrazino]-oxomethyl]amino]-3-methyl-N-(phenylmethyl)butanamide
(2S)-2-[[[(2S)-2-acetamido-3-phenyl-propanoyl]amino]carbamoylamino]-N-(benzyl)-3-methyl-butyramide