6-糠氨基嘌呤的电化学行为及与DNA的相互作用

Voltammetric behavior of 6-furfuryladenine on mercury electrode and its interaction with DNA

应用循环伏安法、微分脉冲伏安法和紫外光谱法研究了6-糠氨基嘌呤（6-KT）在汞电极上的电化学行为及与小牛胸腺DNA的相互作用。结果发现，6-KT的循环伏安曲线显示两对表征为扩散控制和吸附控制的氧化还原波。扩散控制波的氧化峰电流随6-KT浓度在1．00×10^-4-5．00×10^-2mmol·L^-1范围内呈现良好的线性关系。依据预吸附时间和溶液pH值对吸附控制波的还原峰电位和峰电流的影响，讨论了6-KT在汞电极上的吸附机理。另外，6-KT的扩散控制波的还原峰电流随DNA浓度的增加而减小，峰电位正移，紫外吸收峰出现明显的减色效应，认为6-KT乃通过部分插入作用与DNA结合，结合常数为2．60×10^3L·molo^-1。

The electrochemical behavior of 6-furfuryladenine （6-KT）on a mercury electrode has been investigated using cyclic voltammetry ,differential pulse voltammetry and UV spectroscopy. It is found that there are two pairs of redox waves for 6-KT on mercury electrode controlled by adsorption and diffusion,respectively. Based on the effects of accumulation time and pH values on cathodic peak potentials and currents of adsorption controlled waves, their adsorption mechanism is discussed. The anodic peak currents of diffusion-controlled waves increase with the adding concentration of 6-KT. A good linear relationship is exhibited in the concentration range from 1.00 × 10^-4 to 5.00 × 10^-2mmol · L^-1. The cathodic peak currents of 6-KT show an obvious decrease and peak potentials shift positively with the increasing amounts of DNA. In addition,the absorption bands of 6-KT are regularly changed in the present of DNA,the intensity is weakened and the maximal absorption peak value red-shifted. The binding constant of 6-KT with DNA is 2.60 × 10^3 L · mol^-1. Their interactive mode is suggested to be via the part interaction.