Abstract

COPPER(II) AND ZINC(II) COMPLEXES BASED ON ANTIMICROBIAL DRUG SARAFLOXACIN: SYNTHESIS, STRUCTURE AND BIOLOGICAL EVALUATION

Ji Li†, Shao-Song Qian†, Long Zhang, Na Lei, Jie Qin, Hai-Liang Zhu*

ABSTRACT

Two novel sarafloxacin complexes, [CuII(detam)(srx)](ClO4)2·1.5H2O (1) and [ZnII(pydam)(srx)2](ClO4)2 (2) (Hsrx = sarafloxacin, srx = depronated sarafloxacin, detam = N,N-diethyl ethylenediamine, pydam = 1,2-propylene diamine) have been synthesized and characterized by elemental analysis, infrared spectra and single crystal analysis. In both complexes sarafloxacin acts as deprotonated bidentate ligand coordinated to Cu(II) and Zn(II) ions through the pyridone oxygen and a carboxylate oxygen. The antimicrobial activity of the complexes 1,2 against four bacterial species were tested and the results indicated that they exhibit enhanced or similar activity to the free sarafloxacin. Both complexes 1 and 2 exhibit good binding propensity to human or bovine serum albumin protein (HSA or BSA) with relatively high binding constant values. UV studies and cyclic voltammograms of the interaction of sarafloxacin and its complexes with calf-thymus DNA (CT DNA) show that complex 2 exhibits the higher binding constant to CT DNA and the results indicated that sarafloxacin and complexes 1, 2 interact with DNA mainly via intercalation and electrostatic binding. The agarose gel electrophoresis assay reveals complex 1 also shows better cleavage ability.

Keywords: Quinolone; Sarafloxacin; Zn(II) complex; Cu(II) complex; biological evaluation