SMILES: CC(=O)N[C@@H]1[C@H]([C@H]([C@H](O[C@@H]1OC[C@@H](C(=O)[O-])[NH3+])CO)O)O[C@H]2[C@@H]([C@H]([C@H]([C@H](O2)CO)O)O)O
Description: The molecule is an amino acid zwitterion that is the zwitterionic form of O-(3-O-beta-D-galactosyl-N-acetyl-alpha-D-galactosaminyl)-L-serine arising from transfer of a proton from the carboxy to the amino group; major species at pH 7.3. It is a tautomer of an O-(3-O-beta-D-galactosyl-N-acetyl-alpha-D-galactosaminyl)-L-serine.