甘薯茎叶中异槲皮苷及咖啡酰基奎宁酸类衍生物的抗氧化活性  

Antioxidant Activity of Isoquercitrin and Caffeoylquinic Acid Derivatives from Sweet Potato Stems and Leaves

作　　者：李佳银[1,2] 于欢[2] 石伯阳[1,2] 李觅路[2] 陆英[1,2] 

机构地区：[1]湖南农业大学国家植物功能成分利用工程技术研究中心,湖南长沙410128 [2]湖南农业大学园艺园林学院,湖南长沙410128

出　　处：《食品科学》2013年第7期111-114,共4页Food Science

基　　金：湖南省科技厅科技计划项目(2009NK3099);湖南省教育厅科学研究项目(10C0799;2012NK3088)

摘　　要：通过测定还原能力、活性氧自由基的清除作用以及脂质过氧化抑制活性,对甘薯茎叶中含量较高的异槲皮苷(Q-Glu)和异绿原酸A,B,C(3,5-diCQA、3,4-diCQA、4,5-diCQA)4种多酚类化合物的抗氧化活性进行评估。结果显示:4种甘薯茎叶中的多酚类化合物均表现出较高的抗氧化能力,且抗氧化性与化合物浓度呈一定相关性:Q-Glu、3,5-diCQA、3,4-diCQA、4,5-diCQA对DPPH自由基的半清除浓度(IC50)分别为47.27、41.61、43.55、46.02μmol/L;对.OH的IC50值分别为190.99、151.20、151.24、217.31μmol/L;Q-Glu、3,5-diCQA、3,4-diCQA对O2-.的IC50值分别为0.81、0.46、0.71mmol/L;3,5-diCQA、3,4-diCQA、4,5-diCQA对脂质过氧化物的IC50值为3.13、2.53、4.44mmol/L,4,5-diCQA和Q-Glu在实验浓度范围内分别对O2-.清除率和对脂质过氧化物的抑制率低于50%。其中3,5-diCQA的还原能力和清除DPPH自由基、.OH、O2-.等活性氧和自由基的能力最强,3,4-diCQA对脂质过氧化反应的抑制作用最强。4种甘薯茎叶中的多酚类化合物均具有显著抗氧化能力。The antioxidant activity of four major polyphenolic compounds, namely quercetin-3-O-β-D-glucoside （Q-Glu）, 4,5-di-O-caffeoylquinic acid （4,5-diCQA）, 3,4-di-O-caffeoylquinic acid （3,4-diCQA） and 3,5-di-O-caffeoylquinic acid （3,5-diCQA） derived from sweet potato stems and leaves were evaluated based on reducing power, DPPH, hydroxyl and superoxide anion free radical scavenging, and anti-lipidperoxidation assays and compared with that of VC. These four polyphenolic compounds demonstrated strong antioxidant activity in a concentration-dependent manner. The IC50 values of Q-Glu, 3,5-diCQA, 3,4-diCQA, 4,5-diCQA against DPPH and hydroxyl free radicals were 47.27, 41.61, 43.55, 46.02 μmol/L, and 190.99, 151.20, 151.24, 217.31 μmol/L, respectively, whereas the IC50 values of Q-Glu3, 5-diCQA, and 3, 4-diCQA against superoxide anion free radical were 0.81, 0.46, 0.71 mmol/L, respectively. In anti-lipidperoxidation assay the IC50 values of 3,5-diCQA, 3,4-diCQA, and 4,5-diCQA were 4.44, 2.53, 3.13 mmol/L, respectively. Within the studied concentration range, however, 4,5-diCQA and Q-Glu did not reach 50% superoxide anion free radical scavenging and lipidperoxidation. Among these compounds, 3,5-diCQA showed the strongest reducing power and radical scavenging activity, and the antilipidperoxidation activity of 3,4-diCQA was the highest. These results show that these four polyphenolic compounds from sweet potatoes stems and leaves have significant antioxidant effects and are promising natural antioxidants.

关 键 词：甘薯茎叶 多酚类 抗氧化 活性氧自由基 

分 类 号：R151.3[医药卫生—营养与食品卫生学]