中文摘要：

在生理条件（pH 7.4）下,以吖啶橙（AO）为荧光探针,运用荧光光谱、紫外-可见光谱、圆二光谱（CD）和傅里叶转换红外光谱（FT-IR）并结合熔点、粘度及盐效应实验,研究了西玛津与小牛胸腺DNA的相互作用。结果显示,随着溶液中西玛津的浓度增大,DNA-AO复合物的荧光逐渐被猝灭,表明西玛津与AO发生了部分置换作用,而且西玛津的存在使得DNA的熔点和粘度增大,由此推断西玛津与DNA发生嵌插结合。此外,FT-IR光谱分析和盐效应结果表明西玛津与DNA还存在静电结合。计算出的热力学参数表明,疏水作用力是西玛津与DNA结合反应的主要驱动力。

英文摘要：

The interaction between simazine and calf thymus DNA in a pH 7.4 Tris-HC1 buffer was investi- gated with the use of acridine orange （AO） dye as a fluorescent probe by fluorescence,UV-vis absorption, circular dichroism （CD）, and Fourier transform infrared （FT-IR） spectroscopy, as well as DNA melting studies,viscosity measurements and salt effect. It can be concluded that simazine molecules could interca- late into the base pairs of DNA as evidenced by slgnificant fluoresce ce quenching of the DNA-AO complex with the binding of simazine to DNA by substituting for AO in the DNA-AO complex,and increase in melt- ing temperature and relative viscosity of DNA. Furthermore,the FT-IR spectroscopy and salt effect demon- strated that there exists electrostatic attraction between simazine and DNA simultaneously. The thermody- namic parameters suggested that the binding of simazine to DNA was driven mainly by hydrophobic inter- actions.