Sulfonium Moieties as Ammonium Bioisosteres: Novel Ligands for the Alpha7 Nicotinic Acetylcholine Receptor

J Med Chem. 2025 Feb 13;68(3):3157-3179. doi: 10.1021/acs.jmedchem.4c02399. Epub 2025 Jan 20.

Abstract

In the pressing quest of novel treatments for chronic pain, α7 nAChR silent agonists show efficacy as anti-inflammatory modulators and represent a promising strategy. Recent findings reveal that a sulfonium ion can replace the quaternary ammonium nitrogen as an alternative pharmacophore for nAChR silent activation. This study reports the design, synthesis, and electrophysiological evaluation of a new series of sulfonium-based derivatives inspired by the archetypal silent agonist NS6740. Our findings identify NSS-9 as a novel sulfonium α7 silent agonist that effectively alleviates inflammatory pain in a mouse model, highlighting it as a lead compound for further optimization. These results provide insights into the potential of the sulfonium group as a chemotype interacting with the α7 binding site, making it a valuable scaffold for novel α7 silent agonists. Additionally, sulfonium compounds were tested on α9 nAChR, also involved in the cholinergic anti-inflammatory system, identifying one partial agonist and two antagonists.

MeSH terms

  • Animals
  • Azabicyclo Compounds
  • Furans
  • Humans
  • Ligands
  • Male
  • Mice
  • Nicotinic Agonists / chemical synthesis
  • Nicotinic Agonists / chemistry
  • Nicotinic Agonists / pharmacology
  • Quaternary Ammonium Compounds / chemical synthesis
  • Quaternary Ammonium Compounds / chemistry
  • Quaternary Ammonium Compounds / pharmacology
  • Structure-Activity Relationship
  • Sulfonium Compounds* / chemical synthesis
  • Sulfonium Compounds* / chemistry
  • Sulfonium Compounds* / pharmacology
  • alpha7 Nicotinic Acetylcholine Receptor* / agonists
  • alpha7 Nicotinic Acetylcholine Receptor* / metabolism

Substances

  • alpha7 Nicotinic Acetylcholine Receptor
  • Ligands
  • Sulfonium Compounds
  • Nicotinic Agonists
  • Quaternary Ammonium Compounds
  • 1,4-diazabicyclo(3.2.2)nonan-4-yl(5-(3-(trifluoromethyl)phenyl)furan-2-yl)methanone
  • Furans
  • Azabicyclo Compounds