Unichiral 2-(2'-pyrrolidinyl)-1,4-benzodioxanes: the 2R,2'S diastereomer of the N-methyl-7-hydroxy analogue is a potent α4β2- and α6β2-nicotinic acetylcholine receptor partial agonist

J Med Chem. 2011 Nov 10;54(21):7588-601. doi: 10.1021/jm200937t. Epub 2011 Oct 11.

Abstract

A series of unichiral 7-substituted 2-(1'-methyl-2'-pyrrolidinyl)-1,4-benzodioxanes were synthesized and tested for the affinity for the α4β2 and α7 central nicotinic receptors; the 2R,2'S diastereomer of the 7-OH analogue [(R,S)-7], unique in the series, has a high α4β2 affinity (12nM K(i)). N-Demethylation and configuration inversion of the stereocenters greatly weaken its α4β2 affinity, confirming that such a rigid molecule can be considered a new template for α4β2 ligands. Docking analysis showed how (R,S)-7 is capable of strongly and specifically interacting with the amino acidic counterpart of the α4β2 receptor binding site. Further pharmacological characterization demonstrated that (R,S)-7 also has a high affinity for the α6β2 receptor, and in vitro functional tests indicated that it is a potent α4β2 and α6β2 partial agonist, with modest affinity and potency for the α3β4 receptor. Comparison with varenicline, a well-known nicotinic partial agonist used as a smoking cessation aid, interestingly reveals similar nicotinoid profiles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Binding Sites
  • Cerebral Cortex / metabolism
  • Corpus Striatum / drug effects
  • Corpus Striatum / metabolism
  • Dioxanes / chemical synthesis*
  • Dioxanes / chemistry
  • Dioxanes / pharmacology
  • Dopamine / metabolism
  • Drug Partial Agonism
  • HEK293 Cells
  • Humans
  • In Vitro Techniques
  • Male
  • Models, Molecular
  • Nicotinic Agonists / chemical synthesis*
  • Nicotinic Agonists / chemistry
  • Nicotinic Agonists / pharmacology
  • Pyrrolidines / chemical synthesis*
  • Pyrrolidines / chemistry
  • Pyrrolidines / pharmacology
  • Radioligand Assay
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Nicotinic / metabolism*
  • Stereoisomerism
  • Structure-Activity Relationship

Substances

  • 2-(1'-methyl-2'-pyrrolidinyl)-7-hydroxy-1,4-benzodioxane
  • Dioxanes
  • Nicotinic Agonists
  • Pyrrolidines
  • Receptors, Nicotinic
  • alpha6beta2 nicotinic acetylcholine receptor
  • nicotinic receptor alpha4beta2
  • Dopamine