Probes for narcotic receptor mediated phenomena. 46. N-substituted-2,3,4,9,10,10a-hexahydro-1H-1,4a-(epiminoethano)phenanthren-6- and 8-ols - carbocyclic relatives of f-oxide-bridged phenylmorphans.

ABSTRACT: Oxide-bridged phenylmorphans were conceptualized as topologically distinct, structurally rigid ligands with 3-dimensional shapes that could not be appreciably modified on interaction with opioid receptors. An enantiomer of the N-phenethyl-substituted ortho-f isomer was found to have high affinity for the ?-receptor (K(i) = 7 nM) and was about four times more potent than naloxone as an antagonist. In order to examine the effect of introduction of a small amount of flexibility into these molecules, we have replaced the rigid 5-membered oxide ring with a more flexible 6-membered carbon ring. Synthesis of the new N-phenethyl-substituted tricyclic N-substituted-2,3,4,9,10,10a-hexahydro-1H-1,4a-(epiminoethano)phenanthren-6- and 8-ols resulted in a two carbon-bridged relative of the f-isomers, the dihydrofuran ring was replaced by a cyclohexene ring. The carbocyclic compounds had much higher affinity and greater selectivity for the ?-receptor than the f-oxide-bridged phenylmorphans. They were also much more potent ?-antagonists, with activities comparable to naltrexone in the [(35)S]GTP-?-S assay.

SUBMITTER: Li F 

PROVIDER: S-EPMC3569853 | biostudies-literature | 2012 Dec

REPOSITORIES: biostudies-literature