Synthesis, DNA interaction and antimicrobial activities of copper (II) complexes with Schiff base ligands derived from kaempferol and polyamines

Two novel copper (II) complexes 1 and 2 with Schiff base ligands derived from kaempferol and polyamines such as ethylenediamine and diethylenetriamine have been synthesized and characterized by elemental analysis, IR, UV–visible spectroscopy, 1H NMR, molar conductance measurements and molecular modeling studies. The interactions of complexes with DNA have been studied by absorption spectra, viscosity measurements and gel electrophoresis under physiological conditions. The experimental results indicated that two complexes could bind to CT-DNA via an intercalative mode. Noticeably, cleavage DNA (pUC 19) activity of the complex 2 is stronger than that of complex 1. The antimicrobial activities against Escherichia coli and Staphylococcus aureus of two complexes were evaluated by the minimum inhibition concentrations (MIC), which indicated that complex 2 possessed more active against E. coli.