[{"from": "human", "value": "Provide a brief overview of this molecule. [C][C][C][Branch1][Ring2][C][Ring1][Ring2][C][N][C][C][C@][C@@H1][C@H1][Branch2][Ring1][S][C][C][C@][Ring1][=Branch1][Branch2][Ring1][#Branch1][C@H1][Ring1][#Branch2][C][C][=C][Ring1][#Branch2][C][=Branch1][=Branch2][=C][Branch1][Branch1][C][=C][Ring1][=Branch1][O][O][Ring1][#C][O][O]"}, {"from": "gpt", "value": "The molecule is only found in individuals that have used or taken this drug. It is a narcotic used as a pain medication. It appears to be an agonist at kappa opioid receptors and an antagonist or partial agonist at mu opioid receptors. The exact mechanism of action is unknown, but is believed to interact with an opiate receptor site in the CNS (probably in or associated with the limbic system). The opiate antagonistic effect may result from competitive inhibition at the opiate receptor, but may also be a result of other mechanisms. Nalbuphine is thought primarily to be a kappa agonist. It is also a partial mu antagonist analgesic, with some binding to the delta receptor and minimal agonist activity at the sigma receptor."}]