Design, Synthesis, and Biological Evaluation of Pyrrole-2-carboxamide Derivatives as Mycobacterial Membrane Protein Large 3 Inhibitors for Treating Drug-Resistant Tuberculosis

J Med Chem. 2022 Aug 11;65(15):10534-10553. doi: 10.1021/acs.jmedchem.2c00718. Epub 2022 Aug 1.

Abstract

In this work, pyrrole-2-carboxamides were designed with a structure-guided strategy based on the crystal structure of MmpL3 and a pharmacophore model. The structure-activity relationship studies revealed that attaching phenyl and pyridyl groups with electron-withdrawing substituents to the pyrrole ring and attaching bulky substituents to the carboxamide greatly improved anti-TB activity. Most compounds showed potent anti-TB activity (MIC < 0.016 μg/mL) and low cytotoxicity (IC50 > 64 μg/mL). Compound 32 displayed excellent activity against drug-resistant tuberculosis, good microsomal stability, almost no inhibition of the hERG K+ channel, and good in vivo efficacy. Furthermore, the target of the pyrrole-2-carboxamides was identified by measuring their potency against M. smegmatis expressing wild-type and mutated variants of the mmpL3 gene from M. tuberculosis (mmpL3tb) and determining their effect on mycolic acid biosynthesis using a [14C] acetate metabolic labeling assay. The present study provides new MmpL3 inhibitors that are promising anti-TB agents.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural

MeSH terms

  • Antitubercular Agents / pharmacology
  • Antitubercular Agents / therapeutic use
  • Bacterial Proteins / metabolism
  • Humans
  • Membrane Proteins / metabolism
  • Microbial Sensitivity Tests
  • Mycobacterium tuberculosis*
  • Pyrroles / chemistry
  • Structure-Activity Relationship
  • Tuberculosis, Multidrug-Resistant*

Substances

  • Antitubercular Agents
  • Bacterial Proteins
  • Membrane Proteins
  • Pyrroles