光谱和电化学法研究栎精与DNA的相互作用

用紫外-可见光谱法、循环伏安法及线性扫描伏安法研究了栎精(QUE)与DNA在0·01 mol·L-1的NaOAc-HOAc缓冲溶液(pH=4.2)中的相互作用。研究表明,栎精本身具有良好的电化学行为,DNA的加入能导致栎精氧化还原峰电流显著降低。通过测定DNA引入前后体系的一些电化学参数的变化,说明DNA与栎精在该条件下结合生成了一种结合比n(DNA):n(QUE)=1:2的非电活性超分子化合物,条件结合常数为1.3×104。讨论了二者之间的结合模式,二者之间可能同时存在着静电作用和嵌入作用。

Spectroscopic and Electrochemical Studies on the Interaction Between Quercetin and DNA

The interaction between quercetin and DNA in NaOAc-HOAc buffer Solution of pH = 4. 2 was investigated by UV-Vis spectrophotometry and different electrochemical techniques such as cyclic voltammetry and linear sweep voltammetry. It was showed that quercetin was a redox-active compound and after adding DNA to the quercetin solution, both oxidation and reduction currents of quercetin decreased. Compared with those in the absence of DNA, the electrochemical parameters didn't change in the presence of DNA, which indicated that the binding reaction between quercetin and DNA formed an electrochemically inactive supermolecular complex. The composition of the complex was n(DNA) : n(QUE) = 1 : 2 and the conditional binding constant was 1. 3×104. The results showed that the quercetin was binded with DNA not only by intercalation but also by electrostatic binding.