thienorphine thienorphine thienorphine is a very potent, extremely long-acting, orally-active opioid analgesic with mixed agonist–antagonist properties which was developed by the beijing institute of pharmacology and toxicology as a potential treatment for opioid dependence. it is a high-affinity, balanced ligand of the μ- (ki = 0.22 nm), δ- (ki = 0.69 nm), and κ-opioid receptors (ki = 0.14 nm), behaving as a partial agonist of the μ- (emax = 19%–28%) and κ-opioid receptors (emax = 65–75%) and as an antagonist of the δ-opioid receptor. it also possesses relatively low affinity for the nociceptin receptor (ki = 36.5 nm), where it acts as an antagonist. thienorphineclinical dataatc codenoneidentifiers iupac name (1r,2r,6s,15r)-3-(cyclopropylmethyl)-16--15-methoxy-13-oxa-3-azahexacycloicosa-7,9,11-trien-11-ol pubchem cid102212421chemspider58539334chemical and physical dataformulac31h39no4smolar mass521.72 g·mol−13d model (jsmol)interactive image smiles c(ccc1cccs1)(2c34ccc2(536ccn(4cc7c6c(c(cc7)o)o5)cc8cc8)oc)o inchi inchi=1s/c31h39no4s/c1-28(34,10-9-21-4-3-15-37-21)23-17-29-11-12-31(23,35-2)27-30(29)13-14-32(18-19-5-6-19)24(29)16-20-7-8-22(33)26(36-27)25(20)30/h3-4,7-8,15,19,23-24,27,33-34h,5-6,9-14,16-18h2,1-2h3/t23-,24-,27-,28-,29-,30+,31-/m1/s1key:wtgshwlswvfvah-jttxiwglsa-n