[{"from": "human", "value": "Please give me some details about this molecule. [C][=C][C][=Branch1][C][=O][O][/C][\\-Ring1][=Branch1][=C][/C][=Branch1][C][=O][O-1]"}, {"from": "gpt", "value": "The molecule is conjugate base of 4-carboxymethylenebut-2-en-4-olide. It is a conjugate base of a 4-carboxymethylenebut-2-en-4-olide."}]