Chalcone inhibitors of the NorA efflux pump in Staphylococcus aureus whole cells and enriched everted membrane vesicles

Bioorg Med Chem. 2012 Jul 15;20(14):4514-21. doi: 10.1016/j.bmc.2012.05.025. Epub 2012 May 18.

Abstract

A library of 117 chalcones was screened for efflux pump inhibitory (EPI) activity against NorA mediated ethidium bromide efflux. Five of the chalcones (5-7, 9, and 10) were active and two chalcones (9 and 10) were equipotent to reserpine with IC(50)-values of 9.0 and 7.7 μM, respectively. Twenty chalcones were subsequently proved to be inhibitors of the NorA efflux pump in everted membrane vesicles. Compounds 5, 7, and 9 synergistically increased the effect of ciprofloxacin on Staphylococcus aureus. Our results suggest that chalcones might be developed into drugs for overcoming multidrug resistance based on efflux transporters of microorganisms.

MeSH terms

  • Anti-Bacterial Agents / chemical synthesis
  • Anti-Bacterial Agents / chemistry*
  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / antagonists & inhibitors*
  • Bacterial Proteins / metabolism
  • Biological Transport / drug effects
  • Chalcone / analogs & derivatives*
  • Chalcone / chemical synthesis
  • Chalcone / pharmacology
  • Ciprofloxacin / pharmacology
  • Drug Synergism
  • Microbial Sensitivity Tests
  • Multidrug Resistance-Associated Proteins / antagonists & inhibitors*
  • Multidrug Resistance-Associated Proteins / metabolism
  • Staphylococcus aureus / drug effects
  • Staphylococcus aureus / metabolism*

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Multidrug Resistance-Associated Proteins
  • NorA protein, Staphylococcus
  • Ciprofloxacin
  • Chalcone