[{"from": "human", "value": "Could you give me a brief overview of this molecule? [C][N][C][C][Branch1][S][C][=C][C][=Branch1][=Branch2][=C][Branch1][Branch1][C][=C][Ring1][=Branch1][O][O][C][O]"}, {"from": "gpt", "value": "The molecule is a product of the O-methylation of epinephrine by catechol O-methyltransferase, which has no physiologic activity. Increased levels of free metanephrine in patient blood plasma samples may be a diagnostic indicator for pheochromocytoma."}]