New P2X3 receptor antagonists. Part 1: Discovery and optimization of tricyclic compounds

Bioorg Med Chem Lett. 2016 Aug 15;26(16):3896-904. doi: 10.1016/j.bmcl.2016.07.009. Epub 2016 Jul 5.

Abstract

Purinergic P2X3 receptors are trimeric ligand-gated ion channels whose antagonism is an appealing yet challenging and not fully validated drug development idea. With the aim of identification of an orally active, potent human P2X3 receptor antagonist compound that can penetrate the central nervous system, the compound collection of Gedeon Richter was screened. A hit series of tricyclic compounds was subjected to a rapid, two-step optimization process focusing on increasing potency, improving metabolic stability and CNS penetrability. Attempts resulted in compound 65, a potential tool compound for testing P2X3 inhibitory effects in vivo.

Keywords: ATP; Airway hyperractivity; Chirality; HTS campaign; Ion channel; New binding site; P2X3 antagonist; Purinergic receptor.

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Drug Evaluation, Preclinical
  • Heterocyclic Compounds / chemistry*
  • Heterocyclic Compounds, 3-Ring / chemical synthesis*
  • Heterocyclic Compounds, 3-Ring / chemistry
  • Humans
  • Inhibitory Concentration 50
  • Mesylates / chemical synthesis*
  • Mesylates / chemistry
  • Microsomes / metabolism
  • Protein Binding
  • Purinergic P2X Receptor Antagonists / chemical synthesis
  • Purinergic P2X Receptor Antagonists / chemistry*
  • Purinergic P2X Receptor Antagonists / metabolism
  • Receptors, Purinergic P2X3 / chemistry
  • Receptors, Purinergic P2X3 / metabolism*
  • Structure-Activity Relationship

Substances

  • Heterocyclic Compounds
  • Heterocyclic Compounds, 3-Ring
  • Mesylates
  • Purinergic P2X Receptor Antagonists
  • Receptors, Purinergic P2X3
  • Adenosine Triphosphate