Third generation fluoroquinolones antibacterial drug based mixed-ligand Cu(II) complexes: structure, antibacterial activity, superoxide dismutase activity and DNA–interaction approach

Abstract

The copper(II) complexes of the type [Cu(SPF)(Aⁿ)Cl]/[Cu(PFL)(Aⁿ)Cl] (where SPF is sparfloxacin, PFL is pefloxacin and Aⁿ is 2,2′-dipyridylamine/pyridine-2-carboxalehyde/thiophene-2-carboxaldehyde) were synthesised and were found to have a pyramidal geometry with a square base. The superoxide dismutase (SOD) like activity of the complexes were measured using an NBT/NADH/PMS system, these were expressed in terms of the concentration of complex which termianates the formation of formazan by 50% (IC₅₀ value) and found to range from 0.781 to 1.354 μM. The interactions of the complexes with DNA were studied by absorption titration, viscosity measurement and gel electrophoresis under physiological conditions. The antimicrobial efficiency of the complexes were tested on five different microorganisms and showed good biological activity.

Keywords::

• Square pyramidal Cu(II) complexes
• spectrophotometric titration
• IC₅₀
• DNA binding and cleavage

Acknowledgements

The authors would like to thank the Head, Department of Chemistry, Sardar Patel University, India for making it convenient to work in laboratory and the UGC for providing financial support under the scheme “UGC Research Fellowship in Science for Meritorious Students”.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.