The molecule is a 2-(3-amino-3-carboxypropyl)-L-histidine dizwitterion arising from transfer of two protons from the carboxy to the amino groups of 2-[(3S)-3-amino-3-carboxypropyl]-L-histidine. It is a tautomer of a 2-[(3S)-3-amino-3-carboxypropyl]-L-histidine.
(2S)-2-azaniumyl-4-[5-[(2S)-2-azaniumyl-2-carboxylatoethyl]-1H-imidazol-2-yl]butanoate