4-氯-2-(1H-咪唑并[4,5-f][1,10]菲咯啉)苯酚铜(Ⅱ)配合物的晶体结构及其与DNA的相互作用

Crystal Structure and DNA Interaction Property of Cu(Ⅱ) Complex with4-Chloro-2-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)phenol

利用菲咯啉酮衍生物4-氯-2-(1H-咪唑并[4,5-f][1,10]菲咯啉)苯酚(HL)设计合成了一种新的单核铜配合物[Cu(L)(5-Cl-sal)(DMF)]ClO_4·DMF(5-Cl-Hsal=5-氯-水杨醛),用元素分析和X射线单晶衍射等手段对配合物进行了表征。该配合物晶体属三斜晶系,P1空间群。用紫外吸收光谱、荧光光谱和凝胶电泳等方法研究了配合物与DNA的相互作用。结果表明,配合物以插入方式与CT-DNA结合,结合常数为1.02×10~3 L·mol^(-1)。同时配合物也能较大程度淬灭EB-DNA复合物的荧光,表观键合常数为4.37×10~5L·mol_(-1),略小于经典键合常数107 L·mol^(-1)。淬灭机理为动态淬灭。凝胶电泳实验研究表明配合物在H_2O_2存在下可将pBR322质粒DNA切割为开环缺口型DNA和线型DNA,配合物浓度越大,切割效果越好。机理研究显示,配合物切割DNA的反应是由羟基自由基(·OH)和单线态氧(~1O_2)作为活性物种的氧化切割过程。

A new mononuclear copper complex[Cu（L）（5-Cl-sal）（DMF）]ClO4DMF （5-Cl-Hsal=5-chloro-salicylalde-hyde） has been designed and synthesized by phenanthroline derivatives 4-chloro-2-（1H-imidazo[4,5-f] [1,10]phenanthrolin-2-yl）phenol （HL）. It was characterized by element analysis and X-ray single crystal diffraction. The crystal structure of complex belongs to triclinic system with space group P1. Interactions of the complex with DNA binding have been investigated by absorption spectroscopy, fluorescence spectroscopy and agarose gel electrophoresis. The spectrophotometric studies show that the mode of binding of the complex could be intercalation and its binding constant Kb is 1.02103 Lmol-1. At the same time the complex can quench EB-DNA complexes to a large extent. The apparent binding constant value for the complex is 4.37105 Lmol-1, which is slightly less than the classical bond constant 107 Lmol-1. In addition, the quenching mechanism of complex is dynamic quenching. The agarose gel electrophoresis showed that the complex can cleave circular pBR322 plasmid DNA to both nicked and linear forms with addition of hydrogen peroxide, and the higher the concentration, the better the cutting effect. The cleavage mechanism between the complex and plasmid DNA is likely to involve singlet oxygen 1O2 and hydroxyl radical OH as reactive oxygen species.