Discovery of Potent and Selective Transient Receptor Potential Vanilloid 1 (TRPV1) Agonists with Analgesic Effects In Vivo Based on the Functional Conversion Induced by Altering the Orientation of the Indazole Core

J Med Chem. 2022 Sep 8;65(17):11658-11678. doi: 10.1021/acs.jmedchem.2c00469. Epub 2022 Aug 25.

Abstract

Transient receptor potential vanilloid 1 (TRPV1) is a promising target for developing antinociceptive agents. Here, we report the synthesis of N-indazole-4-aryl piperazine carboxamide analogues as TRPV1 modulators. The structure-activity relationship (SAR) reveals that substituting indazole at the 5-/6-position leads to TRPV1 agonism, whereas the 4- and 7-positions of indazole obtain mild antagonism and loss of activity, respectively. The whole-cell clamp patch assay shows that 28 is a potent and selective TRPV1 agonist and it relieves inflammatory and thermal pain by desensitizing the native TRPV1 current in the dorsal root ganglion (DRG) in mice. Additionally, site-directed mutagenesis combined with molecular docking shows an important hydrogen interaction between Arg557 and the indazole of 28. Taken together, our findings provide insight into TRPV1 agonism-antagonism conversion based on the interaction between indazole and Arg557, which provides a strategy to obtain new TRPV1 agonists by structural modification of antagonists. Compound 28 may be used as a lead compound for further optimization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analgesics / pharmacology
  • Animals
  • Capsaicin
  • Ganglia, Spinal
  • Indazoles* / pharmacology
  • Mice
  • Molecular Docking Simulation
  • TRPV Cation Channels*

Substances

  • Analgesics
  • Indazoles
  • TRPV Cation Channels
  • TRPV1 protein, mouse
  • Capsaicin