Copper(II) complexes with norfloxacin and neutral terpyridines: Cytotoxic, antibacterial, superoxide dismutase and DNA-interaction approach

Cu(II) complexes of the type [Cu(NFL)(Ln)Cl] (Ln = substituted terpyridines, NFL = norfloxacin) were synthesised and characterized. Antibacterial activity was assayed against selective Gram(+ve) and Gram(−ve) microorganisms using the double dilution technique. The binding behavior of the complexes toward Herring Sperm (HS) DNA was determined using absorption titration and hydrodynamic measurements, whereas the cleavage efficacy of the complexes toward pUC19 DNA was determined by the gel electrophoresis technique. The brine shrimp bioassay was carried out to study the in vitro cytotoxic properties of the synthesized metal complexes. The superoxide dismutase (SOD) like activity of the complexes was measured using an NBT/NADH/PMS system and is expressed in term of the concentration of complex which terminates the formation of formazan by 50% (IC50 value). The IC50 values were observed to be in the range 0.653–1.344 μM.

Binding of Herring Sperm DNA via an intercalative mode usually results in hypochromism and bathochromism because the intercalation mode involves a strong stacking interaction between an aromatic chromophore and the DNA base pair.Figure optionsDownload as PowerPoint slideHighlights
► Mixed ligand Cu(II) complexes have been synthesized and characterized.
► Cytotoxic activity measurements of the complexes have been performed.
► The antibacterial activity of the complexes against bacteria was checked.
► DNA interaction studies have been carried out using different techniques.
► Superoxide dismutase activities have been measured to obtain IC50 values.