线性扫描伏安法研究美托拉腙与DNA的相互作用

Linear Sweep Voltammetry Study on Interaction between Metolazone and DNA

在NaOH（pH 10．0）介质中，美托拉腙分别在-1．810V和-2．075V处具有2个还原峰，DNA的加入导致美托拉腙的2个还原峰峰电位正移，峰电流下降，表明美托拉腙与DNA之间发生了相互作用，形成了非电活性的化合物。考察了时间、温度、扫描速率、离子强度等条件对该相互作用的影响；结合DNA对美托拉腙紫外吸收光谱的影响，推断美托拉腙分子与DNA分子的相互作用是通过嵌插方式结合。在优化条件下，反应体系在-2．075V处的还原峰电流Ipa与DNA的质量浓度在6～36mg／L范围内呈较好的线性关系，相关系数为0．9948，检出限为3mg／L；通过对反应机制的研究，得到美托拉腙与DNA间的结合常数口为1．334×10^4L／mol，结合数为2。

Metolazone has two reduction peaks at - 1. 810 V and -2. 075 V in pH 10.0 NaOH solution. After adding DNA, the peak current of metolazone decreased and the peak potential shifted positively, which indicated that metolazone could react with DNA and form an electrochemical inactive compound. Effects of reaction time, temperature, sweep rate and ionic intensity on the interaction between DNA and metolazone were studied, and ultraviolet-visible spectra of DNA - metolazone was investigated. The result indicated that the interaction between metolazone and DNA was mainly intercalative model. Under the optimal conditions, a good linear was observed between reduction peak current at -2. 075 V and DNA concentration in the range of 6. 0- 36 mg/L. The linear regression equation was Ipa（10^-5A） = -0. 041 97p ＋ 4. 322 5 with a correlation coefficient of 0. 994 8, and the detection limit was 3.0 mg/L. The combination number and combination constant of DNA - metolazone were calcultaed to be 2 and 1. 334 × 10^4 L/mol, respectively.