蓮子心提取物的抗氧化活性研究

生物工程論文編號:SW192  論文字數:12128,頁數:32

目  錄
中文摘要...................................................................Ⅰ
英文摘要...................................................................Ⅱ
目錄.......................................................................Ⅲ
1. 緒論.....................................................................1
 1.1  自由基方面的研究概況.................................................1
 1.2  自由基的檢測方法.....................................................3
 1.2.1  檢測清除O2·-作用的方法...........................................3
 1.2.2  檢測清除·OH作用的方法...........................................4
 1.3  蓮子心的研究概況.....................................................4
 1.3.1  蓮子心的成分.....................................................4
 1.3.2  蓮子心的藥理作用.................................................5
 1.3.3  蓮子心的開發前景.................................................6
2. 實驗部分.................................................................7
 2.1  主要儀器.............................................................7
 2.2  主要試劑.............................................................7
 2.3  溶液配制.............................................................8
 2.4  基本原理.............................................................8
 2.4.1  羥基自由基·OH實驗原理...........................................8
 2.4.2  超氧陰離子自由基O2·-實驗原理.....................................9
 2.4.3  DPPH自由基實驗原理.............................................9
 2.5  實驗方法.............................................................9
 2.5.1  檢測羥基自由基·OH清除率的實驗方法...............................9
 2.5.2  檢測超氧陰離子自由基O2·-清除率的實驗方法........................10
 2.5.3  檢測DPPH自由基清除率的實驗方法................................10
3. 實驗結果和分析..........................................................12
 3.1  羥基自由基·OH清除率測定實驗........................................12
 3.1.1  羥基自由基·OH清除率測定條件的選擇..............................12
 3.1.2  羥基自由基·OH的清除率的測定....................................15
 3.2  超氧陰離子自由基O2·-清除率測定實驗..................................18
 3.2.1  超氧陰離子自由基O2·-清除率測定條件的選擇........................18
 3.2.2  超氧陰離子自由基O2·-清除率的測定................................20
 3.3  DPPH自由基清除率測定實驗..........................................23
4. 總結與展望..............................................................24
致謝.......................................................................25
參考文獻...................................................................26

摘 要：本文對蓮子心進行了研究，并優化了抗氧化模型。首先建立了檢測Fenton反應產生羥基自由的方法。在pH=3.5條件下，羥自由基與甲基紫作用后使甲基紫褪色，在580nm處測定其吸光度值的變化，可間接測定羥自由基的產生量，從而評價藥物的抗羥基自由基的活性大小。在最佳實驗條件下，當蓮子心粗多糖的濃度為20mg/mL時，清除率為48.83%。在蓮子心的乙醇與丙酮提取物的實驗中，清除率分別為91.36%，78.06%。并建立了鄰苯三酚自氧化模型。鄰苯三酚在pH=8.2條件下自氧化，釋放出O2·-，生成有色中間產物，當清除劑存在時，可清除O2·-，阻止中間產物的積累，溶液在320nm處吸收減弱。當蓮子心粗多糖的濃度為25mg/mL時，清除率為22.98%。在蓮子心的乙醇與丙酮提取物的實驗中，清除率分別為22.80%，44.86%。在DPPH模型中，當蓮子心提取物濃度為10mg/mL時，清除率為30.00%。通過本實驗可知，蓮子心提取物具有一定的抗氧化能力，從而為天然抗氧化試劑的篩選，提供了一定的研究基礎。

關鍵詞：蓮子心提取物；抗氧化；Fenton反應；鄰苯三酚；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