甘薯抗氧化物的分离提取及其生物活性研究

目的:研究甘薯中抗氧化物质的含量,化学成分,分离提取及其生物活性。方法:采用乙醇提取,AB-8大孔树脂吸附纯化方法分离提取甘薯抗氧化物质;通过测定清除超氧阴离子自由基_?O2及·OH的能力及小鼠体内SOD活性等分析其抗氧化能力。结果:甘薯的块根、蔓和叶中均含有抗氧化物质,其含量在组织和品种间有明显差异,最高的品种含量可达0.324%,并且主要分布在甘薯块根中,占总含量的70%以上,提取率达85%以上;初步确定甘薯抗氧化物的主要成分是酚酸类物质,其中包括绿原酸、异绿原酸、新绿原酸和4-O-咖啡酰奎尼酸;当甘薯抗氧化物浓度为90mg/ml时,对_?O2和·OH的清除率分别为88.02%和82.21%;能抑制由·OH引发的脂质过氧化及由H2O2诱导的红细胞氧化溶血;能提高小鼠血清及皮肤细胞中SOD的活性。结论:甘薯中含有较多的酚酸类抗氧化物质,并具有体内外抗氧化活性。

STUDY ON EXTRACTION AND BIOLOGICAL ACTIVITY OF ANTIOXIDANT SUBSTANCE OF SWEET POTATOES

Objective: The chemical composition, extraction and biological activity of antioxidant substance of sweet potatoes were studied. Method: The antioxidant substance was extracted with alcohol and purified with AB-8 big-hole resin and its elimination rate of _?O 2 and OH and SOD activity were determined.Results: The content of antioxidant substance stockpiled respectively in the root tubers, stems and leaves of sweet potatoes and was different in varieties. The highest content in the root tuber was 0.324%, which accounted 70% of total content in sweet potatoes. Its extraction ratio was 85%. The major composition of the antioxidant substance was phenol acid, including chlorogenic acid,isochlorogenic acid,neochlorogenic acid and 4-0-caffeonyl quinic butyl ester. They had intense antioxidant function and their elimination rate to _?O 2 and·OH at concentration 90 mg/ml was 88.02% and 82.21% respectively. The antioxidantsubstance restrained oxidation of lipid and hemolysis of red cell induced by H2O2,and increased SOD activity in serum and skin of mice. Conclusion: Several kinds of phenol acid as antioxidant substance stockpiled in sweet potatoes were proved to have strong antioxidant activity.