[{"from": "human", "value": "Design a molecule that meets the criteria outlined in the description. The molecule is the L-enantiomer of cysteinium. It has a role as a fundamental metabolite. It is a conjugate acid of a L-cysteine and a L-cysteine zwitterion. It is an enantiomer of a D-cysteinium."}, {"from": "gpt", "value": "[C][Branch1][#Branch2][C@@H1][Branch1][=Branch1][C][=Branch1][C][=O][O][NH3+1][S]"}]