吡唑衍生物PTF及其金属配合物与鲑鱼精DNA相互作用研究

Study on the Interaction of Pyrazolyl Derivative PTF and Its Metal Complexes with Salmon Sperm DNA

本研究在模拟生理环境的条件下,运用紫外光谱、荧光光谱、圆二色谱及粘度法来研究2-(3,5-二甲基-1-吡唑基)-6,8-二甲基-1,5,8a,9-四氮杂芴(PTF)及其金属配合物与鲑鱼精DNA的相互作用。结果表明,PTF与Cu(Ⅱ)、Zn(Ⅱ)按配位比2∶1形成配合物;PTF、PTF-Cu(II)和PTF-Zn(Ⅱ)与DNA相互作用后,紫外光谱发生减色效应,并出现等吸收点,结合摩尔比均接近2∶1;荧光光谱产生明显的荧光淬灭效应,结合位点n接近1;圆二色谱正峰与负峰的振幅显著降低,其中PTF-Cu(Ⅱ)和PTF-Zn(Ⅱ)下降趋势更为显著;三者相对粘度和变性温度依次增加。PTF、PTF-Cu(Ⅱ)、PTF-Zn(Ⅱ)对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌、十字花科黑腐病菌均有抑菌活性。综合分析,我们发现PTF、PTF-Cu(Ⅱ)、PTF-Zn(Ⅱ)与DNA的作用方式均为嵌插模式,结合能力依次为PTF-Zn(Ⅱ)>PTF-Cu(Ⅱ)>PTF。

A systematic study on the interaction between 2-(3,5-dimethyl-pyrazol-1-yl)-6,8-dimethyl-4b,9-dihydro-1,5,8 a,9-Tetraaza-Fluorene(PTF)or its metal complexes and salmon sperm DNA was investigated using ultraviolet(UV),fluorescence,circular dichroism(CD)spectrum and viscometric method under simulated physiological conditions.Our results showed that the PTF can form a complex with Cu(Ⅱ)and Zn(Ⅱ)at a coordination ratio of 2∶1.A significant hypochromic effect on the UV spectrum of DNA was appeared after the action of PTF,PTF-Cu(Ⅱ)and PTF-Zn(Ⅱ),accompanied by the equal absorption points,closed to the 2∶1 molar ratio of combination.After a series of interactions of three PTF or its metal complexes,the fluorescence spectrum of the DNA was quenched and their binding site n is close to 1.The amplitude of positive and negative peaks of CD spectrum decreased significantly,especially in the trend of action of PTF-Cu(Ⅱ)and PTF-Zn(Ⅱ).The relative viscosity and denaturation temperature of DNA increased in turn after the action of PTF,PTF-Cu(Ⅱ)and PTF-Zn(Ⅱ).Moreover,the PTF,PTF-Cu(Ⅱ)and PTF-Zn(Ⅱ)all had good antibacterial activities on Escherichia coli,Staphylococcus aureus,Bacillus subtilis and Cruciferous black rot.As a whole,our comprehensive analysis showed that the interaction modes of PTF,PTF-Cu(Ⅱ),PTF-Zn(Ⅱ)and DNA were all intercalation,and the binding ability trend was PTF-Zn(Ⅱ)>PTF-Cu(Ⅱ)>PTF.