Applying Molecular Networking for the Detection of Natural Sources and Analogues of the Selective Gq Protein Inhibitor FR900359

J Nat Prod. 2018 Jul 27;81(7):1628-1635. doi: 10.1021/acs.jnatprod.8b00222. Epub 2018 Jun 26.

Abstract

The cyclic depsipeptide FR900359 (FR), isolated from the traditional Chinese medicine plant Ardisia crenata, is a potent Gq protein inhibitor and thus a valuable tool to study Gq-mediated signaling of G protein-coupled receptors. Two new FR analogues (3 and 4) were isolated from A. crenata together with the known analogues 1 and 2. The structures of compounds 3 and 4 were established by NMR spectroscopic data and MS-based molecular networking followed by in-depth LCMS2 analysis. The latter approach led to the annotation of further FR analogues 5-9. Comparative bioactivity tests of compounds 1-4 along with the parent molecule FR showed high-affinity binding to Gq proteins in the low nanomolar range (IC50 = 2.3-16.8 nM) for all analogues as well as equipotent inhibition of Gq signaling, which gives important SAR insights into this valuable natural product. Additionally, FR was detected from leaves of five other Ardisia species, among them the non-nodulated leaves of Ardisia lucida, implying a much broader distribution of FR than originally anticipated.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Ardisia / chemistry*
  • Ardisia / classification
  • CHO Cells
  • Computer Communication Networks
  • Cricetulus
  • Depsipeptides / analysis*
  • Depsipeptides / chemistry
  • Drugs, Chinese Herbal / analysis*
  • Drugs, Chinese Herbal / chemistry
  • GTP-Binding Protein alpha Subunits, Gq-G11 / antagonists & inhibitors*
  • Magnetic Resonance Spectroscopy
  • Molecular Structure
  • Signal Transduction

Substances

  • Depsipeptides
  • Drugs, Chinese Herbal
  • FR900359
  • GTP-Binding Protein alpha Subunits, Gq-G11