线性扫描伏安法研究美托拉腙与DNA的相互作用

在NaOH(pH 10.0)介质中,美托拉腙分别在-1.810 V和-2.075 V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-2.075 V处的还原峰电流I_(pa)与DNA的质量浓度在6 ～36 mg/L范围内呈较好的线性关系,相关系数为0.994 8,检出限为3 mg/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β为1.334×10~4 L/mol,结合数为2.

Linear Sweep Voltammetry Study on Interaction between Metolazone and DNA

Metolazone has two reduction peaks at - 1. 810 V and -2. 075 V in pH 10.0 NaOH solu-tion. 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 inac-tive compound. Effects of reaction time, temperature, sweep rate and ionic intensity on the interac-tion 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 regres-sion equation was I_(pa)(10~(-5) A) = -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.