[{"from": "human", "value": "Describe this molecule. [C][C@@H1][Branch1][O][C][C][=Branch1][C][=O][C][=Branch1][C][=O][O][O]"}, {"from": "gpt", "value": "The molecule is an optically active form of 4-hydroxy-2-oxopentanoic acid having 4S-configuration. It is a conjugate acid of a (S)-4-hydroxy-2-oxopentanoate."}]