is conjugate acid of is conjugate base of histidine histidinium(1+) 156.16262 2-ammonio-3-(1H-imidazol-3-ium-4-yl)propanoate An alpha-amino-acid cation that has formula C6H10N3O2. C6H10N3O2 CHEBI:32531 HNDVDQJCIGZPNO-UHFFFAOYSA-O InChI=1S/C6H9N3O2/c7-5(6(10)11)1-4-2-8-3-9-4/h2-3,5H,1,7H2,(H,8,9)(H,10,11)/p+1 [NH3+]C(Cc1c[nH]c[nH+]1)C([O-])=O chebi_ontology histidine monocation histidinium histidinium(1+) histidinium(2+) alpha-amino-acid cation