Antibacterial activity and mechanism of action of the benzazole acrylonitrile-based compounds: In vitro, spectroscopic, and docking studies

Eur J Med Chem. 2017 Aug 18:136:270-282. doi: 10.1016/j.ejmech.2017.05.010. Epub 2017 May 4.

Abstract

A new series of pyrimidine derivatives 5, 9a-d and 12a-d was synthesized by an efficient procedure. The antibacterial activity of the new compounds was studied against four bacterial strains. Compound 5 was found to exhibit the highest potency, with = 1.0 μg/ml, against both Escherichia coli and Pseudomonas aeruginosa when compared with amoxicillin (MIC = 1.0-1.5 μg/mL). Transmission electron microscope results confirmed that activities against bacteria occurred via rupturing of the cell wall. Molecular modeling results suggested that compounds 5, 9a-d and 12a-d have the potential to irreversibly bind to the penicillin-binding protein (PBP) Ser62 residue in the active site and were able to overcome amoxicillin resistance in bacteria by inhibiting the β-lactamase enzyme. Docking studies showed that compounds 5, 9a-d and 12a-d inhibit the β-lactamase enzyme through covalent bonding with Ser70. The synergistic effect with amoxicillin was studied. The newly synthesized compounds reported in this study warrant further consideration as prospective antimicrobial agents.

Keywords: Antibacterial; Docking; PBP; Pyrimidine; Synthesis; β-lactamase.

MeSH terms

  • Acrylonitrile / chemical synthesis
  • Acrylonitrile / chemistry
  • Acrylonitrile / pharmacology*
  • Anti-Bacterial Agents / chemical synthesis
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology*
  • Circular Dichroism
  • Dose-Response Relationship, Drug
  • Escherichia coli / drug effects*
  • Escherichia coli / enzymology
  • Magnetic Resonance Spectroscopy
  • Microbial Sensitivity Tests
  • Molecular Docking Simulation
  • Molecular Structure
  • Pseudomonas aeruginosa / drug effects*
  • Pseudomonas aeruginosa / enzymology
  • Spectrophotometry, Ultraviolet
  • Structure-Activity Relationship
  • beta-Lactamase Inhibitors / chemical synthesis
  • beta-Lactamase Inhibitors / chemistry
  • beta-Lactamase Inhibitors / pharmacology*
  • beta-Lactamases / metabolism*

Substances

  • Anti-Bacterial Agents
  • beta-Lactamase Inhibitors
  • beta-Lactamases
  • Acrylonitrile