Synthesis, Antibacterial Activities and Nuclease Properties of Ternary Copper(II) Complex Containing 2-(2'-Pyridyl)benzothiazole and Glycinate

A new ternary complex [Cu(PBT)(Gly)(H2O)]ClO4 (PBT=2-(2'-pyridyl)benzothiazole, and Gly=glycinate) has been synthesized and characterized by elemental analysis, molar conductivity, and IR methods. The complex, structurally characterized by single-crystal X-ray crystallography, shows a slightly distorted square-pyramidal coordination geometry in which two nitrogen atoms of PBT and the carboxylate oxygen atom O and the amino nitrogen atom N of Gly bind at the basal plane, a water molecule is coordinated at the apical position. The complex, Cu(ClO4)2 and free PBT were each tested for their ability to inhibit the growth of two Gram(-) (Escherichia coli, Salmonella) and two Gram(+) (Bacillus subtilis, Staphylococcus aureus) microorganisms. The complex showed good antibacterial activities against the microorganisms compared with free PBT and Cu(ClO4)2. The interaction between the complex and calf thymus DNA in aqueous solution was investigated using electronic spectroscopy, fluorescence spectroscopy, circular dichroic spectroscopy, and viscosity measurements. Results suggest that the complex could bind to DNA by an intercalative mode. In addition, the result of agarose gel electrophoresis showed that the complex can cleave the plasmid DNA by hydroxyl radicals and singlet oxygen-like species under the condition of physiological pH and room temperature.