SMILES: CC1([C@@H](N2[C@H](S1)[C@@H](C2=O)[NH3+])C(=O)[O-])C
Description: The molecule is zwitterionic form of 6-aminopenicillanic acid arising from migration of a proton from the carboxy group to the 6-amino group; major species at pH 7.3. It is a conjugate acid of a 6-aminopenicillanate. It is a tautomer of a 6-aminopenicillanic acid.