[{"from": "human", "value": "Design a molecule that meets the criteria outlined in the description. The molecule is a branched-chain fatty acid and metabolite of the lactone prodrug simvastatin, whose sodium salt is potentially useful for the treatment of thalassaemias and haemoglobinopathies. It has a role as a metabolite."}, {"from": "gpt", "value": "[C][C][C][Branch1][C][C][Branch1][C][C][C][=Branch1][C][=O][O]"}]