Antibacterial Activities and Nuclease Properties of Two New Ternary Copper（ll） Complexes with 2-（4＇-Thiazolyl）- benzimidazole and 2,2＇-Bipyridine/1,10-phenanthroline

• Published in: 中国化学：英文版 2011, Vol.29 (7), p.1380-1388
• Main Author: 任祥祥 陈佳阳 乐学义
• Format: Article
• Language: English
• Subjects: 噻唑基; 小牛胸腺DNA; 抗菌活性; 氯化铜; 联吡啶; 苯并咪唑; 菲罗啉; 金黄色葡萄球菌
• ISSN: 1001-604X; 1614-7065

Two new complexes： [Cu（TBZ）（bipy）Cl]Cl[H2O （1） and [Cu（TBZ）（phen）CI]CloH20 （2） [TBZ=2-（4＇-thiazolyl）- benzimidazole, phen = 1,10-phenanthroline and bipy =2,2＇-bipyridine] have been synthesized and characterized by elemental analysis, molar conductivity, IR, and UV-vis methods. Complex 2, structurally characterized by single-crystal X-ray crystallography, crystallizes in the monoclinic space group P21/c in a unit cell of a = 0.85257（12） nm, b=2.5358（4） nm, c=1.15151（13） nm, β=118.721（8）°, V=2.183.2（5） nm^3, Z=4, Dc=1.624 gocm 3, μ= 1.367 mm^-1. The complexes, free ligands and chloride copper（II） salt were each tested for their ability to inhibit the growth of two gram-positive （B. subtilis and S. aureus） and two gram-negative （Salmonella and E. coli） bacteria. The complexes showed good antibacterial activities against the microorganisms. The interaction between the com- plexes and calf thymus DNA in aqueous solution was investigated adopting electronic absorption spectroscopy, fluorescence spectroscopy, viscosity measurements and cyclic voltammetry. Results suggest that the two complexes can bind to DNA by intercalative mode. In addition, the result of agarose gel electrophoresis suggested that the complexes can cleave the plasmid DNA at physiological pH and room temperature. Mechanistic studies with different inhibiting reagents reveal that hydroxyl radicals, and a singlet oxygen-like copper-oxo species are all involved in the DNA scission process mediated by the complexes.