[{"from": "human", "value": "Generate a molecule based on this description. The molecule is a fatty acid methyl ester and an octadecanoate ester. It has a role as a metabolite."}, {"from": "gpt", "value": "[C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][=Branch1][C][=O][O][C]"}]