The molecule is an ammonium ion that is a derivative of L-histidine having a 3-carboxy-3-(methylammonio)propyl group at the 2-position on the imidazole ring. It is a conjugate acid of a 2-[3-carboxylato-3-(methylammonio)propyl]-L-histidine dizwitterion.
[3-[5-[(2S)-2-amino-2-carboxyethyl]-1H-imidazol-2-yl]-1-carboxypropyl]-methylazanium