[{"from": "human", "value": "Generate a molecule based on the given description. The molecule is a 3-oxo monocarboxylic acid anion. It has a role as a human metabolite. It is functionally related to a propionate. It is a conjugate base of a 3-oxopropanoic acid."}, {"from": "gpt", "value": "[C][Branch1][Ring1][C][=O][C][=Branch1][C][=O][O-1]"}]