[{"from": "human", "value": "Describe this molecule. [C][=C][Branch1][Branch2][C][C][C][=Branch1][C][=O][O-1][C][=Branch1][C][=O][O-1]"}, {"from": "gpt", "value": "The molecule is dicarboxylate anion of 2-methylideneglutaric acid; major species at pH 7.3. It is a conjugate base of a 2-methylideneglutaric acid."}]