[{"from": "human", "value": "What can you tell me about this molecule? [C][S][C][C][C][C][=Branch1][C][=O][C][=Branch1][C][=O][O]"}, {"from": "gpt", "value": "The molecule is an omega-(methylthio)-2-oxocarboxylic acid. It is a conjugate acid of a 5-methylthio-2-oxopentanoate."}]