Discovery of New Chemical Entities for Old Targets: Insights on the Lead Optimization of Chromone-Based Monoamine Oxidase B (MAO-B) Inhibitors

J Med Chem. 2016 Jun 23;59(12):5879-93. doi: 10.1021/acs.jmedchem.6b00527. Epub 2016 Jun 10.

Abstract

The discovery of new chemical entities endowed with potent, selective, and reversible monoamine oxidase B inhibitory activity is a clinically relevant subject. Therefore, a small library of chromone derivatives was synthesized and screened toward human monoamine oxidase isoforms (hMAO-A and hMAO-B). The structure-activity relationships studies strengthen the importance of the amide spacer and the direct linkage of carbonyl group to the γ-pyrone ring, along with the presence of meta and para substituents in the exocyclic ring. The most potent MAO-B inhibitors were N-(3'-chlorophenyl)-4-oxo-4H-chromene-3-carboxamide (20) (IC50 = 403 pM) and N-(3',4'-dimethylphenyl)-4-oxo-4H-chromene-3-carboxamide (27) (IC50 = 669 pM), acting as competitive and noncompetitive reversible inhibitors, respectively. Computational docking studies provided insights into enzyme-inhibitor interactions and a rationale for the observed selectivity and potency. Compound 27 stands out due to its favorable toxicological profile and physicochemical properties, which pointed toward blood-brain barrier permeability, thus being a valid candidate for subsequent animal studies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Survival / drug effects
  • Chromones / chemical synthesis
  • Chromones / chemistry
  • Chromones / pharmacology*
  • Dose-Response Relationship, Drug
  • Drug Discovery*
  • Humans
  • Models, Molecular
  • Molecular Structure
  • Monoamine Oxidase / metabolism*
  • Monoamine Oxidase Inhibitors / chemical synthesis
  • Monoamine Oxidase Inhibitors / chemistry
  • Monoamine Oxidase Inhibitors / pharmacology*
  • Structure-Activity Relationship
  • Tumor Cells, Cultured

Substances

  • Chromones
  • Monoamine Oxidase Inhibitors
  • Monoamine Oxidase