5-[(二氨基亚甲基)氨基]-2-氧代戊酸

H-ARG-LEU-OH

5-[[amino-[(2-methylpropan-2-yl)oxycarbonylamino]methylidene]amino]-2-[(2-methylpropan-2-yl)oxycarbonylamino]pentanoic acid

H-ARG-GLU-OH

H-ARG-SER-OH