[{"from": "human", "value": "Create a molecule with the structure as the one described. The molecule is a member of the class of oxopentanoates that is the conjugate base of 4-oxopentanoic acid. It has a role as a plant metabolite. It is a conjugate base of a 4-oxopentanoic acid."}, {"from": "gpt", "value": "[C][C][=Branch1][C][=O][C][C][C][=Branch1][C][=O][O-1]"}]