- Design, syntheses, and pharmacological characterization of 17-cyclopropylmethyl-3,14β-dihydroxy-4,5α-epoxy-6α-(isoquinoline-3′-carboxamido)morphinan analogues as opioid receptor ligands
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A series of 17-cyclopropylmethyl-3,14β-dihydroxy-4,5α-epoxy-6α-(isoquinoline-3′-carboxamido)morphinan (NAQ) analogues were synthesized and pharmacologically characterized to study their structure-activity relationship at the mu opioid receptor (MOR). The competition binding assay showed two-atom spacer and aromatic side chain were optimal for MOR selectivity. Meanwhile, substitutions at the 1′- and/or 4′-position of the isoquinoline ring retained or improved MOR selectivity over the kappa opioid receptor while still possessing above 20-fold MOR selectivity over the delta opioid receptor. In contrast, substitutions at the 6′- and/or 7′-position of the isoquinoline ring reduced MOR selectivity as well as MOR efficacy. Among this series of ligands, compound 11 acted as an antagonist when challenged with morphine in warm-water tail immersion assay and produced less significant withdrawal symptoms compared to naltrexone in morphine-pelleted mice. Compound 11 also antagonized the intracellular Ca2+ increase induced by DAMGO. Molecular dynamics simulation studies of 11 in three opioid receptors indicated orientation of the 6′-nitro group varied significantly in the different 'address' domains of the receptors and played a crucial role in the observed binding affinities and selectivity. Collectively, the current findings provide valuable insights for future development of NAQ-based MOR selective ligands.
- Yuan, Yunyun,Zaidi, Saheem A.,Stevens, David L.,Scoggins, Krista L.,Mosier, Philip D.,Kellogg, Glen E.,Dewey, William L.,Selley, Dana E.,Zhang, Yan
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supporting information
p. 1701 - 1715
(2015/03/30)
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- Structure activity relationship studies of 17-cyclopropylmethyl-3,14β- dihydroxy-4,5α-epoxy-6α-(isoquinoline-3′-carboxamido) morphinan (NAQ) analogues as potent opioid receptor ligands: Preliminary results on the role of electronic characteristics for affinity and function
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17-Cyclopropylmethyl-3,14β-dihydroxy-4,5α-epoxy-6α- (isoquinoline-3′-carboxamido)morphinan (NAQ) was previously designed following the 'message-address' concept and was identified as a potent and highly selective mu opioid receptor (MOR) ligand based on its pharmacological profile. We here report the preliminary structure activity relationship (SAR) studies of this novel lead compound. For the new ligands synthesized as NAQ analogues, their binding assay results showed that a longer spacer and a saturated ring system of the side chain were unfavorable for their MOR selectivity over the kappa and delta opioid receptors. In contrast, substitutions with different electronic properties at either 1′- or 4′-position of the isoquinoline ring of the side chain were generally acceptable for reasonable MOR selectivity. The majority of NAQ analogues retained low efficacy at the MOR compared to NAQ in the 35S- GTP[γS] binding assays while electron-withdrawing groups at 1′-position of the isoquinoline ring induced higher MOR stimulation than electron-donating groups did. In summary, the electronic characteristics of substituents at 1′- or 4′-position of the isoquinoline ring in NAQ seem to be critical and need to be further tuned up to achieve higher MOR selectivity and lower MOR stimulation.
- Yuan, Yunyun,Elbegdorj, Orgil,Beletskaya, Irina O.,Selley, Dana E.,Zhang, Yan
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supporting information
p. 5045 - 5048
(2013/09/12)
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- NON-PEPTIDYL, POTENT, AND SELECTIVE MU OPIOID RECEPTOR ANTAGONISTS
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Selective, non-peptide antagonists of the ma opioid receptor { MOR) and methods of their use are provided. The antagonists may be used, for example, to identify MOR agonists in competitive binding assays, and to treat conditions related to addiction in which MOR is involved, e.g. heroin, prescription drug and alcohol addiction.
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Page/Page column 64
(2010/08/08)
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