[{"from": "human", "value": "Design a molecule that meets the criteria outlined in the description. The molecule is an S-substituted L-cysteine where the S-substituent is specified as (2-hydroxyethyl)sulfane. It has a role as a metabolite."}, {"from": "gpt", "value": "[C][Branch1][=C][C][S][S][C][C@@H1][Branch1][=Branch1][C][=Branch1][C][=O][O][N][O]"}]