Synthesis and biological evaluation of novel sigma-1 receptor antagonists based on pyrimidine scaffold as agents for treating neuropathic pain

J Med Chem. 2014 Dec 26;57(24):10404-23. doi: 10.1021/jm501207r. Epub 2014 Dec 4.

Abstract

The discovery and synthesis of a new series of pyrimidines as potent sigma-1 receptor (σ1R) antagonists, associated with pharmacological antineuropathic pain activity, are the focus of this article. The new compounds were evaluated in vitro in σ-1 and σ-2 receptor binding assays. The nature of the pyrimidine scaffold was crucial for activity, and a basic amine was shown to be necessary according to the known pharmacophoric model. The most promising derivative was 5-chloro-2-(4-chlorophenyl)-4-methyl-6-(3-(piperidin-1-yl)propoxy)pyrimidine (137), which exhibited a high binding affinity to σ1R receptor (Ki σ1 = 1.06 nM) and good σ-1/2 selectivity (1344-fold). In in vivo tests, compound 137 exerted dose-dependent antinociceptive effects in mice formalin model and rats CCI models of neuropathic pain. In addition, no motor impairments were found in rotarod tests; acceptable pharmacokinetic properties were also noted. These data suggest compound 137 may constitute a novel class of drugs for the treatment of neuropathic pain.

MeSH terms

  • Animals
  • Behavior, Animal / drug effects
  • Carbon Tetrachloride / toxicity
  • Ether-A-Go-Go Potassium Channels / antagonists & inhibitors
  • Guinea Pigs
  • Mice
  • Molecular Structure
  • Motor Activity
  • Neuralgia / chemically induced
  • Neuralgia / prevention & control*
  • Neuroprotective Agents / chemical synthesis*
  • Neuroprotective Agents / pharmacology*
  • Nociceptive Pain / prevention & control*
  • Piperidines / chemical synthesis*
  • Piperidines / pharmacology*
  • Pyrimidines / chemical synthesis*
  • Pyrimidines / chemistry*
  • Pyrimidines / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, sigma / antagonists & inhibitors*
  • Sigma-1 Receptor
  • Structure-Activity Relationship

Substances

  • 5-chloro-2-(4-chlorophenyl)-4-methyl-6-(3-(piperidin-1-yl)propoxy)pyrimidine
  • Ether-A-Go-Go Potassium Channels
  • Neuroprotective Agents
  • Piperidines
  • Pyrimidines
  • Receptors, sigma
  • Carbon Tetrachloride
  • pyrimidine