[{"from": "human", "value": "Synthesize a molecule that matches the given characteristics. The molecule is a monocarboxylic acid anion resulting from the removal of a proton from the carboxy group of acetic acid. It has a role as a human metabolite and a Saccharomyces cerevisiae metabolite. It is a conjugate base of an acetic acid."}, {"from": "gpt", "value": "[C][C][=Branch1][C][=O][O-1]"}]