[{"from": "human", "value": "Create a molecule that satisfies the conditions outlined in the description. The molecule is a C4-dicarboxylate resulting from the removal of a proton from both carboxylic acid groups of methylmalonic acid. It has a role as a human metabolite. It is functionally related to a malonate(2-). It is a conjugate base of a methylmalonate(1-)."}, {"from": "gpt", "value": "[C][C][Branch1][=Branch1][C][=Branch1][C][=O][O-1][C][=Branch1][C][=O][O-1]"}]