莲子心提取物的抗氧化活性研究

生物工程论文编号:SW192  论文字数:12128,页数:32

目  录
中文摘要...................................................................Ⅰ
英文摘要...................................................................Ⅱ
目录.......................................................................Ⅲ
1. 绪论.....................................................................1
 1.1  自由基方面的研究概况.................................................1
 1.2  自由基的检测方法.....................................................3
 1.2.1  检测清除O2·-作用的方法...........................................3
 1.2.2  检测清除·OH作用的方法...........................................4
 1.3  莲子心的研究概况.....................................................4
 1.3.1  莲子心的成分.....................................................4
 1.3.2  莲子心的药理作用.................................................5
 1.3.3  莲子心的开发前景.................................................6
2. 实验部分.................................................................7
 2.1  主要仪器.............................................................7
 2.2  主要试剂.............................................................7
 2.3  溶液配制.............................................................8
 2.4  基本原理.............................................................8
 2.4.1  羟基自由基·OH实验原理...........................................8
 2.4.2  超氧阴离子自由基O2·-实验原理.....................................9
 2.4.3  DPPH自由基实验原理.............................................9
 2.5  实验方法.............................................................9
 2.5.1  检测羟基自由基·OH清除率的实验方法...............................9
 2.5.2  检测超氧阴离子自由基O2·-清除率的实验方法........................10
 2.5.3  检测DPPH自由基清除率的实验方法................................10
3. 实验结果和分析..........................................................12
 3.1  羟基自由基·OH清除率测定实验........................................12
 3.1.1  羟基自由基·OH清除率测定条件的选择..............................12
 3.1.2  羟基自由基·OH的清除率的测定....................................15
 3.2  超氧阴离子自由基O2·-清除率测定实验..................................18
 3.2.1  超氧阴离子自由基O2·-清除率测定条件的选择........................18
 3.2.2  超氧阴离子自由基O2·-清除率的测定................................20
 3.3  DPPH自由基清除率测定实验..........................................23
4. 总结与展望..............................................................24
致谢.......................................................................25
参考文献...................................................................26

摘 要：本文对莲子心进行了研究，并优化了抗氧化模型。首先建立了检测Fenton反应产生羟基自由的方法。在pH=3.5条件下，羟自由基与甲基紫作用后使甲基紫褪色，在580nm处测定其吸光度值的变化，可间接测定羟自由基的产生量，从而评价药物的抗羟基自由基的活性大小。在最佳实验条件下，当莲子心粗多糖的浓度为20mg/mL时，清除率为48.83%。在莲子心的乙醇与丙酮提取物的实验中，清除率分别为91.36%，78.06%。并建立了邻苯三酚自氧化模型。邻苯三酚在pH=8.2条件下自氧化，释放出O2·-，生成有色中间产物，当清除剂存在时，可清除O2·-，阻止中间产物的积累，溶液在320nm处吸收减弱。当莲子心粗多糖的浓度为25mg/mL时，清除率为22.98%。在莲子心的乙醇与丙酮提取物的实验中，清除率分别为22.80%，44.86%。在DPPH模型中，当莲子心提取物浓度为10mg/mL时，清除率为30.00%。通过本实验可知，莲子心提取物具有一定的抗氧化能力，从而为天然抗氧化试剂的筛选，提供了一定的研究基础。

关键词：莲子心提取物；抗氧化；Fenton反应；邻苯三酚；DPPH

Abstract:Several antioxidant models has been studied and optimized of the Nelumbo nucifera Gaertn in this article. First, a new spectrophotometric method for the determination of the hydro- xyl radical ·OH produced by Fenton reaction has been proposed. The hydroxyl radical ·OH and methyl violet react at pH=3.5. The change in absorbance, corresponding to color intensity chan- ge of methyl violet can be measured at λ=580nm, so the amount of ·OH can be determined indir- ectly. The activity of medicament will be appraised.In condition, when the concentration of the polysaccharides from embryo of the seeds of Nelumbo nucifera Gaertn is 20mg/mL, scavenging achieves 48.83%. In the experiment of athanol and acetone extracts, scavenging are 91.36%, 78.06%.A method of pyrogallic has been proposed.At pH=8.2 ,the pyrogallic is oxidated to rele- asing the O2·-,producing coloured substance. When the antioxidant existences, may eliminates the O2·-, prevents the substance accumulating. the absorption of the solution weakens at λ=320 nm. When the concentration of the polysaccharides from embryo of the seeds of Nelumbo nucife- ra Gaertn is 25mg/mL, scavenging is 22.98%. In the experiment of athanol and acetone extracts, scaveng- ing are 22.80%, 44.86%.In DPPH model,when the concentration is 25mg/mL, scaveng- ing is 30.00%. Through this experiment,we may know that the extracts of the seeds of Nelumbo nucifera Gaertn has the antioxidant ability. It will provide a certain method for producing the natrue antioxidant.
Key words：Extracts from embryo of the seeds of Nelumbo nucifera Gaertn; antioxidant activity; Fenton reaction; Pyrogallic; DPPH model