quadazocine quadazocine quadazocine (win-44,441) is an opioid antagonist of the benzomorphan family which is used in scientific research. it acts as a silent antagonist at all three of the major opioid receptors—μ, κ, and δ, but with a significant preference in affinity for the μ receptor and the κ2 subtype. as such, it has been touted as a "κ2-selective" antagonist, though this is not entirely accurate on account of its similar affinity for the μ receptor. as would be expected, quadazocine reverses the effects (e.g., analgesia) of opioid agonists like morphine and fentanyl in animals. quadazocineclinical dataatc codenoneidentifiers iupac name 1-cyclopentyl-5-trideca-2,4,6-trien-13-yl]-3-pentanone cas number71276-43-2 ypubchem cid115077chemspider102983uniix9bmd58553comptox dashboard (epa)dtxsid30990187 chemical and physical dataformulac25h37no2molar mass383.576 g·mol−13d model (jsmol)interactive image smiles o=c(ccc1cccc1)ccc4(3n(cc4(c2c(ccc(o)c2)c3)c)c)c inchi inchi=1s/c25h37no2/c1-24-14-15-26(3)23(16-19-9-11-21(28)17-22(19)24)25(24,2)13-12-20(27)10-8-18-6-4-5-7-18/h9,11,17-18,23,28h,4-8,10,12-16h2,1-3h3/t23-,24+,25?/m1/s1key:loywoycpswpkfh-csiquldisa-n