2015最新范文白藜芦醇与紫檀芪抗氧化活性差异的 电化学研究.pdf

78 2012, Vol. 33, No. 05 食品科学※基础研究
白藜芦醇与紫檀芪抗氧化活性差异的
电化学研究
余沐洋,张萌,高凌峰,何建波*
(合肥工业大学化工学院,农产品生物化工教育部工程研究中心,安徽合肥 230009)
摘要:为揭示白藜芦醇(反式)与其衍生物紫檀芪的抗氧化活性差异的内在原因,对两种物质的氧化机理进行研究。
采用循环伏安法考察 pH 值、富集时间对氧化过程的影响,采用薄层长光程紫外- 可见光谱电化学方法原位监测氧
化产物的形成。结果表明:紫檀芪在油性碳糊电极表面上的吸附富集作用远强于白藜芦醇;两者的初始氧化都发
生在对位羟基上,通过一电子一质子传递步骤生成苯氧自由基中间体;紫檀芪自由基中间体易于耦合迅速转化为二
聚体产物,而白藜芦醇自由基在碱性介质中需经历较难进行的中间双键断裂途径,转化为可溶性小分子产物。紫
檀芪较强的亲脂性引起的富集作用以及氧化中间体的快速二聚化,是其具有较强抗氧化活性的重要原因。
关键词:抗氧化活性;白藜芦醇;紫檀芪;循环伏安法;原位光谱电化学
An Electrochemical Study of the Difference in Antioxidant Activity between Resveratrol and Pterostilbene
YU Mu-yang,ZHANG Meng,GAO Ling-feng,HE Jian-bo*
(Engineering Research Centre of Bio-process, Ministry of Education, School of Chemical Engineering,
Hefei University of Technology, Hefei 230009, China)
Abstract: The oxidation mechanisms of trans-resveratrol and its derivative pterostilbene were studied to better understand the
difference in antioxidant activity between the pounds. The effects of pH and accumulation time were examined by
cyclic voltammetry, and the formation of oxidation products was in situ by thin layer UV-Vis spectroelectrochemistry. It was
observed that adsorptive accumulation of pterostilbene on the oleaginous surface of the carbon paste working electrode was
much stronger than that of resveratrol. The initial oxidation of both the stilbenes occurred at the p-hydroxyl gro