[{"from": "human", "value": "Based on the given information, design a molecule that meets the desired specifications. The molecule is a hydroxy fatty acid anion that is the conjugate base of 3-hydroxybutyric acid, obtained by deprotonation of the carboxy group; major species at pH 7.3. It has a role as a human metabolite. It is functionally related to a butyrate. It is a conjugate base of a 3-hydroxybutyric acid."}, {"from": "gpt", "value": "[C][C][Branch1][#Branch1][C][C][=Branch1][C][=O][O-1][O]"}]