摘要：槲皮素属黄酮类化合物，具有抗炎、抗菌、抗氧化、抗病毒、抗癌及抗血小板聚集等多种生物活性，已广泛应用于医药食品行业。本文设计了四种体外纯化学体系，以研究槲皮素对DPPH·、O2-·和·OH三种自由基的清除能力及总抗氧化活性，并以芦丁作阳性对照。实验结果表明：在一定浓度范围内，槲皮素清除自由基的能力及总抗氧化活性与其浓度呈正相关性；与阳性对照芦丁相比，槲皮素的总抗氧化活性及对O2-·、DPPH·的清除作用较强，但对·OH的清除作用较弱；超过一定浓度范围后，槲皮素对超氧阴离子的清除能力随其浓度的增加反而降低。我们的研究工作可为槲皮素的进一步开发利用提供数据支持。94615

毕业论文关键词：黄酮类化合物﹑槲皮素﹑抗氧化活性

Abstract: Quercetin is a flavonoid compound, and have a variety of biological activities, such as anti-inflammatory, anti-bacterial, anti-oxidation, anti-virus, anti-cancer and anti-platelet aggregation, which has been widely used in the pharmaceutical food industry。 In order to evaluate its antioxidant properties, four pure chemical systems in vitro were designed to study the scavenging ability of quercetin on DPPH·, O2-·and·OH radicals and the total antioxidant。 Rutin was used as a positive control。 The results showed that quercetin had certern antioxidant ability, its scavenging ability of free radicals and total antioxidant activity were positively correlated with its concentration in a certain concentration range。 Compared with the positive control rutin,the total antioxidant activity of quercetin and the removal of O2- and DPPH were stronger than that of rutin, but the scavenging effect of·OH was weaker。 After a certain concentration range, the removal ability of quercetin to superoxide anion decreases with the increase of its concentration。 Our research work can provide data support for the further development and utilization of quercetin。

Keywords: Flavonoids, Quercetin , Antioxidant activity 

目录

1 前言 6

1。1 槲皮素的生物学特性 6

1。2 槲皮素的抗氧化活性机理 7

2 材料与方法 7

2。1 材料与仪器 7

2。2 实验方法 8

2。2。1 稀释样品液 8

2。2。2 FRAP法 8

2。2。3 超氧阴离子自由基（O2-·）体系 9

2。2。4 羟基自由基（·OH）体系 10

2。2。5 DPPH·自由基体系 11

3 结果与分析 12

3。1 槲皮素总抗氧化活性评价 12

3。3 槲皮素的羟基自由基体系评价 13

3。4 槲皮素的DPPH·自由基体系评价 14

3。5 槲皮素对超氧阴离子和羟基自由基清除作用的比较 15

小结 16

参考文献: 17

致谢 19

1 前言

槲皮素(quercetin)是膳食中最常见的黄酮类化合物之一，广泛分布于蔬菜、水果、中草药和许多饮料（茶、咖啡、红酒和果汁）中。已知槲皮素对超氧阴离子[1]、羟基自由基[2]、脂质过氧化自由基[2]的清除作用与自身结构中富含的酚羟基有关。已有研究表明槲皮素具有抗氧化、抗炎、抗衰老、抗癌变、抗突变、抗动脉粥样硬化、预防高血压、抗肿瘤等多种生理功能，而其抗衰老、抗突变、抗动脉粥样硬化等生物学活性都与抗氧化有关[3]。据文献报道槲皮素在体外可通过直接清除活性氧自由基、螯合金属离子、抑制LDL及DNA氧化损伤发挥其抗氧化作用[4]。