【作者】 孟祖超；

【导师】 郑建斌；

【作者基本信息】 西北大学 ， 分析化学， 2005， 硕士

【摘要】 用电分析化学方法研究有机药物一直是一个重要的研究领域。首先,电分析化学具有灵敏度高、选择性好、响应时间短、简便和经济实用等优点:其次,对电极过程的研究有利于提高分析方法的选择性、灵敏度,而根据极谱波的产生或消失可以推断新产物的形成或药物的分解;另外,研究体液中的原始药物及其代谢产物的极谱伏安行为有利于探讨药物在体内的作用机制。本论文采用多种电分析方法并结合波谱分析,对喜树碱、甲基橙皮甙、利培酮、多潘立酮、酮康哗等含羰基有机化合物的电还原特性及其应用进行了研究。这些研究可为生物医药研究提供理论基础和实用依据,对拓宽电分析化学应用范围有重要意义。全文共分六章,作者的主要贡献有以下五点: 1、采用循环伏安法、线性扫描伏安法、常规脉冲伏安法和恒电位电解法等电化学方法研究了喜树碱在pH 2.09～9.07 Britton-Robinson（B-R）缓冲溶液中的电化学行为,并采用常规脉冲伏安法对喜树叶肉中喜树碱的含量进行了测定。在pH2.09～5.46 B-R缓冲溶液中,喜树碱仅产生一个还原波:在pH 6.01～9.07 B-R缓冲溶液中,喜树碱产生两个还原波。研究证实,P₁波为两电子还原波;P₂波为喜树碱的单电子不可逆吸附还原波;P₃波为催化氢波和P₂波的进一步还原波的重叠波,具有吸附性。其中,P₁波与喜树碱浓度在2.0×10^-6～2.0×10^-5 mol·L^-1（r=0.9998）具有线性关系,检出限为8.0×10^-7mol·L^-1。 2、研究了在pH2.05～6.37酸性水溶液中甲基橙皮甙（MH）的电化学行为和清除活性氧自由基的能力。在-0.6V～-1.6V的范围内,MH能产生三个还原波。其中,P₁波为MH还原为吸附态产物所产生的还原波,P₂波和P₃波分别为质子化MH的单电子不可逆还原波及还原中间体自由基的单电子不可逆还原波,且P₃波的峰高与浓度有线性关系。此外,用线性扫描伏安法研究了MH清除邻苯三酚自氧化产生的活性氧自由基的能力,证实MH是一种有效的活性氧自由基清除剂。 3、采用多种电化学技术,详细研究了在pH 7.0～10.32 B-R缓冲溶液和0.2mol·L^-1NaOH溶液中利培酮的电化学行为,并采用线性扫描伏安法对利培酮片剂更多还原

【Abstract】 Organic drugs investigated by electroanalytical methods are always an important field in analytical chemistry. For one thing, the electroanalytical techniques are characterized by simplicity, sensitivity," cost-effectiveness, precision, accuracy and speed. For another, the selectivity and sensitivity of analytical method can be further improved by investigating electrode process. And according to the appearance and disappearance of polarographic wave, we can deduce the generation of new product or decomposition of medicines. In addition, due to the existing resemblance between electrochemical and biological reactions we can assume that the reduction mechanisms taking place at the electrode and in the body share similar principles. In this thesis, organic drugs, especially some carbonyl compounds were studied systematically by several electroanalytical methods and the spectrum analysis. These studies may provide theoretical and practical basis for biomedicine, and have important significance in broadening the application range of the electroanalytical chemistry. This thesis consists of six chapters.1. The advance of electrochemical investigation of carbonyl compounds was reviewed with 105 references.2. In pH 2.09-9.07 Britton-Robinson （B-R） buffer solutions, the electrochemical behaviors of camptothecine （CPT） were studied by several electrochemical methods at a hanging mercury drop electrode, and a new method for the determination of CPT was established by normal pulse voltammetry. In different pH range of B-R buffer solutions, CPT could cause three reduction waves P₁, P₂ and P₃. Their reaction mechanisms were preliminarily presented. P₁ wave was a two-electron wave. P₂ wavewas a one-electron wave. P3 wave could be split into two waves P3a and P3b- P3a was a catalytic hydrogen wave, and P3b was further reduction of P2 wave with the property of adsorption. A linear relationship between the peak currents of Pi wave and the concentration of CPT was obtained in the range of 2.0x10’6².0xl0"5 molL"1. The determination limit was 8.0 X 10"7 mol-L"1.3. A detailed study of the polarographic reduction of methylhesperidine was presented. The methylhesperidine could yield three reduction waves in aqueous medium from pH 2.05 to 6.37. Pi wave was the absorptive frontal wave of P2. And P2 wave was an irreversible adsorptive wave of protonized MH involving one proton and one electron. P3 wave was also an irreversible adsorptive wave with one electron as the further reduction of P2 wave. And the peak currents of P3 wave were proportional to the concentration of methylhesperidine. In addition, its effect of eleminating superoxide anion radical caused by the auto-oxidation of pyrogallol was studied in pH 8.2 HCl-tris buffer solution. The results proved MH has antioxidant quality which is very efficient.4. The electrochemical behaviors of risperidone were studied in pH 7.07 10.32 B-R buffer solutions and 0.2 mol-L’1 NaOH solution by several electrochemical methods, and a new method for determination of risperidone in risperidone tablets was described. Risperidone yielded one wave P| as pH of B-R buffer solution was changed from 7.07 up to 10.07, which was a catalytic hydrogen wave. Additional two waves P2 and P3 were exhibited in pH 10.32 B-R buffer solution. P2 wave was an irreversible adsorption reduction wave involving one electron. P3 could be split into P3a and P3t,. Of them, P3a was the further reduction wave of P2, and P3b was a catalytic hydrogen wave. Otherwise, the first-order derivative peak current of Pi wave and the concentration of risperidone were proportional in the range of 1.6x10" ².0x10"6 mol-L". The determination limit was l.OxlO"6 mol-L"1.5. The polarographic behaviors of domperidone and its application were studied. In pH 8.05-10.92 NH3-NH4CI buffer solutions, domperidone could yield a reduction wave. The experiment showed that the electroactive centers of domperidone were the C=O bonds. The electrode reaction mechanism was preliminarily presented. In therange of S.OxlO^-l.OxlO"4 molL’1, the peak currents of domperidone were proportional to the concentration of domperidone. The method was used to determine domperidone.6. The electrochemical behaviors of ketoconazole in pH 3.25⁶.08 NaAc-HAc buffer solutions were studied at a hanging mercury drop electrode. And the mechanism of ketoconazole was preliminarily presented.更多还原