Synthesis, nicotinic acetylcholine receptor binding, in vitro and in vivo pharmacology properties of 3'-(substituted pyridinyl)-deschloroepibatidine analogs

Bioorg Med Chem. 2015 Sep 1;23(17):5693-701. doi: 10.1016/j.bmc.2015.07.021. Epub 2015 Jul 17.

Abstract

Over the last several years we have synthesized and studied the in vitro and in vivo nAChR pharmacological properties of epibatidine (4) analogs. In this study we report the synthesis, nAChR in vitro and in vivo pharmacological properties of 3'-(substituted pyridinyl)-deschloroepibatidine analogs (5a-e and 6a-e). All of the analogs had high binding affinity for α4β2(∗)-nAChRs. Several of the analogs were potent antagonists of α4β2-nAChRs in in vitro efficacy tests and were potent antagonists of nicotine-induced antinociception in the mouse tail-flick test. Compound 6b had a Ki = 0.13 nM in the binding assay, 25- and 46-fold selectivity for the α4β2(∗)-nAChR relative to the α3β4- and α7-nAChR, respectively, in the in vitro efficacy test and an AD50 = 0.13 μg/kg in the tail-flick test. Combined with favorable calculated physiochemical properties compared to varenicline, our findings suggest that 6b should be considered for development as a potential pharmacotherapy for treating nicotine addiction and other CNS disorders.

Keywords: Epibatidine analogs; In vitro/in vivo study; Nicotine receptor; Varenicline; nAChR antagonist.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Bridged Bicyclo Compounds, Heterocyclic / chemical synthesis*
  • Bridged Bicyclo Compounds, Heterocyclic / chemistry
  • Bridged Bicyclo Compounds, Heterocyclic / pharmacology
  • Humans
  • Mice
  • Molecular Structure
  • Pyridines / chemical synthesis*
  • Pyridines / chemistry
  • Pyridines / pharmacology
  • Rats
  • Receptors, Nicotinic / metabolism
  • Structure-Activity Relationship
  • Tobacco / chemistry*

Substances

  • Bridged Bicyclo Compounds, Heterocyclic
  • Pyridines
  • Receptors, Nicotinic
  • deschloroepibatidine