Structure and biological properties of the copper(II) complex with the quinolone antibacterial drug N-propyl-norfloxacin and 2,2'-bipyridine

J Inorg Biochem. 2007 Jan;101(1):64-73. doi: 10.1016/j.jinorgbio.2006.07.019. Epub 2006 Aug 25.

Abstract

The neutral mononuclear copper complex with the quinolone antibacterial drug N-propyl-protected norfloxacin, Hpr-norfloxacin, in the presence of the nitrogen donor heterocyclic ligand 2,2'-bipyridine has been prepared and characterized. The crystal structure of (chloro)(2,2'-bipyridine)(pr-norfloxacinato)copper(II), 1, has been determined and refined with X-ray crystallography. X-band electron paramagnetic resonance (=EPR) spectroscopy at liquid helium temperatures from powdered samples indicates the presence of dimeric units in consistency with the crystal structure. In aqueous solutions of 1 the EPR behavior indicates mixture of dimeric and monomeric species. The antimicrobial activity of the complex has been tested on three different microorganisms and the best inhibition (MIC=0.25mugmL(-1)) has been exhibited against Escherichia coli. The study of the interaction of the complex with calf-thymus DNA has been performed with diverse spectroscopic techniques and has shown that complex 1 is bound to calf-thymus DNA by the intercalative mode. Potential anticancer cytostatic and cytotoxic effects of complex 1 on human promyelocytic leukemia HL-60 and human chronic myelogenous leukemia K562 cell lines have been investigated. Complex 1 shows an increased antiproliferative and necrotic effect on both HL-60 and K562 human leukemia cells in comparison to the free pr-norfloxacin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 2,2'-Dipyridyl / chemistry*
  • 2,2'-Dipyridyl / pharmacology*
  • Animals
  • Anti-Bacterial Agents / chemistry*
  • Anti-Bacterial Agents / pharmacology*
  • Cattle
  • Cell Line, Tumor
  • Circular Dichroism
  • Copper / chemistry*
  • DNA / drug effects
  • Drug Screening Assays, Antitumor
  • Electron Spin Resonance Spectroscopy
  • Escherichia coli / drug effects
  • Microbial Sensitivity Tests
  • Molecular Structure
  • Norfloxacin / analogs & derivatives*
  • Norfloxacin / chemistry
  • Norfloxacin / pharmacology
  • Spectrophotometry, Infrared
  • Spectrophotometry, Ultraviolet

Substances

  • Anti-Bacterial Agents
  • 2,2'-Dipyridyl
  • Copper
  • DNA
  • Norfloxacin