Structural comparison of Mtb-DHFR and h-DHFR for design, synthesis and evaluation of selective non-pteridine analogues as antitubercular agents

Bioorg Chem. 2018 Oct:80:319-333. doi: 10.1016/j.bioorg.2018.04.022. Epub 2018 May 11.

Abstract

Tuberculosis is an infectious disease that affects millions of population every year. Mtb-DHFR is a validated target that is vital for nucleic acids biosynthesis and therefore DNA formation and cell replication. This paper report identification and synthesis of novel compounds for selective inhibition of Mtb-DHFR and unleash the selective structural features necessary to inhibit the same. Virtual screening of databases was carried out to identify novel compounds on the basis of difference between the binding pockets of the two proteins. Consensus docking was performed to improve upon the results and best ten hits were selected. Hit 1 was subjected to analogues design and the analogues were docked against Mtb-DHFR. From the docking results 11 compounds were selected for synthesis and biological assay against H37Rv. Most potent compound (IND-07) was tested for selectivity using enzymatic assay against Mtb-DHFR and h-DHFR. The compounds were found to have good inhibitory activity (25-200 µM) against H37Rv and in enzyme assay against Mtb-DHFR and h-DHFR the compound was found selective towards Mtb-DHFR with selectivity index of 6.53. This work helped to identify indole moiety as novel scaffold for development of novel selective Mtb-DHFR inhibitors as antimycobacterial agents.

Keywords: 1DF7; 1OHJ; Antimycobacterial; Antitubercular; Consensus docking; Indole moiety; Mtb-DHFR inhibitors.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Antitubercular Agents / chemical synthesis*
  • Antitubercular Agents / metabolism
  • Antitubercular Agents / pharmacology
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / metabolism
  • Binding Sites
  • Catalytic Domain
  • Drug Design*
  • Enzyme Inhibitors / chemical synthesis*
  • Enzyme Inhibitors / metabolism
  • Enzyme Inhibitors / pharmacology
  • Humans
  • Hydrogen Bonding
  • Microbial Sensitivity Tests
  • Molecular Docking Simulation
  • Mycobacterium tuberculosis / drug effects
  • Mycobacterium tuberculosis / enzymology*
  • Protein Structure, Tertiary
  • Pteridines / chemistry
  • Structure-Activity Relationship
  • Tetrahydrofolate Dehydrogenase / chemistry*
  • Tetrahydrofolate Dehydrogenase / metabolism

Substances

  • Antitubercular Agents
  • Bacterial Proteins
  • Enzyme Inhibitors
  • Pteridines
  • Tetrahydrofolate Dehydrogenase