[{"from": "human", "value": "Describe this molecule. [C][Branch1][#Branch2][C@@H1][Branch1][=Branch1][C][=Branch1][C][=O][O-1][NH3+1][S][C][C@@H1][Branch1][=Branch1][C][=Branch1][C][=O][O-1][NH3+1]"}, {"from": "gpt", "value": "The molecule is an L-alpha-amino acid zwitterion that is the dizwitterionic form of L-lanthionine obtained by migration of protons from both carboxy groups to the amino groups; major species at pH 7.3. It is functionally related to a L-cysteine zwitterion. It is a tautomer of a L-lanthionine."}]