(2S)-1-[(2S)-2,6-diazaniumylhexanoyl]pyrrolidine-2-carboxylate (2S)-1-[(2S)-2,6-diammonio-1-oxohexyl]-2-pyrrolidinecarboxylate (2S)-1-[(2S)-2,6-diammoniohexanoyl]pyrrolidine-2-carboxylate ZINC03791059