3,5-二碘水杨醛缩2,6-二氨基吡啶席夫碱及其金属配合物的制备及与ct-DNA的作用研究

Synthesis of 3,5-Diiodo-salicylalidehyde and 2,6-Diaminopyridine Schiff Base and ct-DNA cleavage by its Metal Complexes

由3,5-二碘水杨醛和2,6-二氨基吡啶反应合成了席夫碱配体,将其与4种过渡金属硝酸盐反应生成相应的配合物,通过元素分析、电子光谱、红外光谱、TG-DTA及摩尔电导率确定配合物的结构和组成为[M(NO3)L].H2O,由Gaussian03程序对其进行了优化计算,给出了配合物的主要键参数。通过紫外吸收光谱、荧光发射光谱、粘度法、稳态荧光猝灭方法及其与溴化乙锭(EB)的竞争实验研究了Co(Ⅱ)配合物与小牛胸腺DNA(ct-DNA)的作用情况,结果显示,配合物与ct-DNA作用时,其紫外吸收产生明显减色效应,荧光强度增强;EB-DNA体系的荧光强度随配合物的加入迅速减弱;在ct-DNA存在下,配合物的荧光强度随猝灭剂K4[Fe(CN)6]体积的增加变化较为缓慢;配合物的加入使ct-DNA的粘度增加;这些结果表明配合物是以插入方式与ct-DNA结合的。打孔法研究配合物的抗菌活性结果表明,配合物对藤黄微球菌(M.luteus)有良好的抑制作用。

The Schiff base consisted of 3,5-diiodo-salicylalidehyde and 2,6-diaminopyridine and four transition metal complexes with it as ligand had been synthesized and characterized by elemental analysis,UV spectra,IR spectra,TG-DTG,and molar conductance analysis.The main bond parameters of the complexes were calculated by full-optimized molecular geometries with Gaussian03 program.It was found that the fluorescence intensity of the complexes reduced with the raising coordination ability of solvent.DNA-binding properties of the complexes were investigated by using the technologies including UV,fluorescent,viscosities,steady-state emission quenching and DNA competitive binding with ethidium bromide（EB）.The results showed that the intensity of absorption peaks and fluorescence peaks increased while the complexes interacted with ct-DNA.The complexes will lead the fluorescence intensity of EB-DNA system to decrease sharply;the effect of quencher K4[Fe（CN）6] on the emission of complexes-DNA system was weaker than that of the complexes themselves.The relative specific viscosity of ct-DNA was increased as increasing the concentration of complexes.All of the results indicated that the binding-mode between complexes and ct-DNA was intercalation.In addition,the complexes were assayed against M.luteus by punch method.