羧甲基壳聚糖-Cu(Ⅱ)配合物的抑菌活性及其与DNA的相互作用

Antibacterial Activity of Carboxymethyl Chitosan-Cu(Ⅱ)Complex and Interaction with DNA

2倍稀释法研究了羧甲基壳聚糖-Cu(Ⅱ)配合物(CMC-Cu)的抑菌活性,采用循环伏安法和光谱法研究了CMC-Cu配合物与鲱鱼精脱氧核糖核酸(DNA)的相互作用。结果表明:CMCCu配合物对枯草芽孢杆菌(B.subtilis)、金黄色葡萄球菌(St.aureus)、大肠杆菌(E.coli)、绿脓杆菌(P.aeruginosa)具有良好的抑制作用。CMC-Cu在0.442V处有一灵敏的氧化峰,中心Cu2+在玻碳电极上的反应过程主要由扩散过程控制;当滴加DNA后,CMC-Cu的氧化峰电流降低,且式量电位负移。CMC-Cu的加入使DNA的吸收峰发生蓝移且有增色效应,并对DNA-中性红体系荧光具有增强效应。CMC-Cu与DNA之间的作用模式为静电作用。

The antibacterial activity of carboxymethyl chitosan-Cu（Ⅱ） complex （CMC-Cu） was studied in vitro. The interaction between CMC-Cu and herring sperm DNA was investigated by cyclic voltammetry and spectroscopy. Results showed that CMC-Cu had good antibacterial activity against B.subtilis, St.aureus, E.coli and P.aeruginosa. An oxidation peak of CMC-Cu appeared at 0.442 V, the electrochemical reaction of the Cu2＋ on the glass carbon electrode was controlled by the process of diffusion. Adding DNA into the CMC-Cu solution, the oxidation peak current decreased and the peak potential shifted to negitive. More over, the absorption intensity of DNA was strengthened and blue shifted with the increasing of CMC-Cu concentration. The fluorescence intensity of DNA-NR system was increased by CMC-Cu. The interaction mode between CMC-Cu and herring sperm DNA was electrostatic.