[{"from": "human", "value": "Design a molecule that meets the criteria outlined in the description. The molecule is an S-conjugate L-cysteine zwitterion substituted by a 2-methyl-3-sulfanylbutan-1-ol group; major species at pH 7.3."}, {"from": "gpt", "value": "[C][C][Branch1][Ring1][C][O][C][Branch1][C][C][S][C][C@@H1][Branch1][=Branch1][C][=Branch1][C][=O][O-1][NH3+1]"}]