谷胱甘肽和硒的反应机理研究

【作者】 金花；

【导师】 崔胜云；

【作者基本信息】 延边大学 ， 分析化学， 2006， 硕士

【摘要】 许多研究报道了亚硒酸盐与含巯基的化合物反应（如谷胱甘肽）是催化氧化反应。在此，我们通过动态的ESI-MS，对在水溶液中简单混合反应的谷胱甘肽和亚硒酸钠作用产物及中间产物进行了表征，且利用动态的UV-vis分光光度法和¹H-NMR进行分析测定。实验结果表明，谷胱甘肽和亚硒酸钠反应是动态的氧化还原反应，在反应第一步，GSH直接氧化还原反应形成GSSG和不稳定的GSSeSG中间体，而后不稳定的GSSeSG中间体进一步与剩余的GSH氧化还原反应生成GSSG和零价硒。当GSSG的数量显著增加或溶液的酸性增加时，GSH的氧化还原电位E（E⁰）′（GSSG／2GSH）=-250mV（NHE）显著转化为正电位，使GSSG具有高氧化性，并与零价硒发生氧化还原反应。这些可以通过另外的m／z 418的不稳定中间阴离子[GSS-Se]^-。的化学组成证明。这些反应机理可通过动态ESI-MS，¹H-NMR和UV-vis分光光度法测定。 此外，我们还探讨了利用天然高分子壳聚糖为软模板水相制备纳米硒的方法。研究了诸多反应因素，如反应时间、反应物浓度、超声等实验条件对产物粒度大小、形貌的影响。结果表明，当n（GSH）：n（Na₂ SeO₃）=8：1、壳聚糖质量分数为0.4‰、25℃下反应3h后，可获得均匀稳定的球形纳米硒颗粒，平均粒径约50nm，且在一定条件下得到了棒状纳米硒。本文通过紫外分光光度法、X射线衍射、透射电镜、扫描电镜等对产物进行了结构分析和形貌观察。更多还原

【Abstract】 Selenite has been found to be an active catalyst for the oxidation of sulfhydryl compound, such as GSH. Considering the biological importance of GSH oxidation and the implication of sulfhydryl compounds in selenium poisoning and other biological activities, more information on selenite oxidation of GSH in enzyme-free conditions is desirable. Herein, we describes glutathione and sodium selenite simply mixed in aqueous solutions, the interaction products and transient intermediate were identified and characterized by using dynamic ESI tandem mass spectrometry. The mixture solutions were also characterized by using dynamic UV-vis spectrometry and ~1H-NMR spectrometry. The experiment results indicated that dynamic redox reactions take place between GSH and selenite. In the first step, GSH is directly oxidated to form diglutathione and unstable selenodiglutathone(GS-Se-SG) intermediate. Then the unstable selenodiglutathione intermediate further reacted with lelt GSH to form diglutathione and elemental selenium Se~0. As the amount of GSSG significantly increased or acidity of the solution increased , the redox potential of GSH(E~0’(GSSG/2GSH) = -250mV(NHE)) significantly shifted to the positive direction, which makes the GSSG have more oxidant properties and leads to the redox reactions between GSSG and Se, which can be demonstrated by another unstable intermediate anions(m/z 418 [GSS-Se]~-). The reaction mechanism between GSH and sodium selenite is proposed through the dynamic ESI-MS, 1H-NMR and UV-vis spectrometric measurements.Furthermore, we also synthesize Selenium nanoparticles in aqueous solution by using chitosan (CTS) as a soft template. In this part experiment, we study many factors which can affect the size and form of the product. The factors include reaction time, concentration of reactants and ultrasonic irradiation. After 3h reaction of the mixture更多还原