摘要
采用线性扫描伏安法、循环伏安法和常规脉冲伏安法电化学手段详细研究了改性药物 3′ 大豆甙元磺酸钠 ( 3′ daidzeinsulfonicsodium ,Dss)在pH 1 0～ 6 2的水溶液中的电化学行为 .在不同pH范围内得到了Dss的三个还原波 .研究证实 ,在pH <3 2条件下所获得的Pc1,Pc2 波分别为质子化的Dss的单电子不可逆吸附还原波及还原中间体自由基的单电子单质子不可逆吸附还原波 ;在 3 2 <pH <6 2条件下所获得的Pc3 波 ,属于Dss后随质子化的单电子不可逆吸附还原波 ,而还原中间体自由基的单电子波被氢波掩盖 .测得在单分子层饱和吸附的条件下 ,每一个Dss分子所占汞电极面积为 0 664nm2 .此外 ,通过邻苯三酚自氧化产生活性氧自由基再还原 ,对Dss清除活性氧自由基能力进行了研究 ,从电化学角度对其药理机制进行了探讨 ,研究证实Dss具有较强的抗氧化性 ,是一种有效的活性氧自由基清除剂 .
A detailed study on the electrochemical behaviour of 3'-daidzein sulfonic sodium (Dss) in aqueous medium from pH 1.0 to 6.2 was carried out by means of linear sweep voltammetry, cyclic voltammetry and normal pulse voltammetry. Over the studied pH range, three reduction waves of Dss were achieved. In pH 1.0 similar to 3.2, Dss showed two reduction,waves with the peak potentials at - 0.62 V (Pc-1, vs. SCE) and - 1.15 V (Pc-2, vs. SCE), respectively. The former was an irreversible adsorptive wave of protonized Dss involving one electron and the latter was also an irreversible adsorptive wave of reduction intermediate radical of Dss involving one electron and one proton. Between pH 3.2. similar to 6.2, Dss showed one reduction wave (Pc-3), which was an irreversible adsorptive wave involving one electron and one proton. Wave of reduction intermediate radical of Dss was overlapped because of a discharge of hydrogen ion into the electrolyte solution. On the surface of mercury electrode, the adsorption of Dss obeyed Frumkin isotherm. In. addition, its scavenging effect on superoxide anion radical was studied by the auto-oxidation of pyrogallol in HCl-tris buffer solution (pH 8.2). in order to explain its peculiar biological effects. The experiments have proved that Dss has antioxidant quality, and it is an efficient free radical scavenger of superoxide anion radical.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2003年第4期487-494,共8页
Acta Chimica Sinica
基金
国家自然科学基金 (No.2 0 2 750 30 )
教育部科学技术研究重点项目 (No.0 2 1 87)
高等学校骨干教师资助计划 (No.GG 1 50 71 0 0 6 2 877)
陕西省教育厅专项科研基金 (No.0 1JK0 76)资助项目
