剑麻花提取物的抗氧化活性研究

Study on Antioxidant Activities of Different Fractions of Ethanol Extract and Polysaccharides of Sisal Flower

本实验分别就剑麻花乙醇提取物石油醚相、乙酸乙酯相和正丁醇相以及剑麻花多糖对DPPH·、·OH和O-2·三种自由基的清除率进行了测定,并与合成抗氧化剂TBHQ、BHT进行对比。结果表明,剑麻花提取物各相对DPPH·、·OH和O-2·三种自由基均有一定的清除效果。且清除率与浓度存在剂量依赖关系。其中以乙酸乙酯相对DPPH·的清除效率最高,而正丁醇相对O-2·清除率最高;在浓度为64μg/ml下剑麻花提取物石油醚相对·OH的清除率最高,而乙酸乙酯相和正丁醇相对·OH的清除率与合成抗氧化剂TBHQ和BHT相近。提示剑麻花提取物石油醚相是一种潜在的羟自由基清除剂。另外,在相同浓度下,剑麻花多糖对·OH和O-2·的清除率均低于剑麻花乙醇提取物各相。

In this study, petroleum ether-phase, ethyl acetate-phase and n-butanol-phase fractions of ethanol extract of sisal flower and polysaccharides extracted from the ethanol extraction residue were prepared and then their antioxidant activities were evaluated by measuring the scavenging rates to DPPH radical （DPPH·）, hydroxyl radical （·OH） and superoxide anion radical （O2^-·） respectively. The results showed that the three fractions of ethanol extract all have certain activity to scavenge DPPH·, ·OH and O^2-· with dose-dependent manner. Furthermore, compared to the other two, the ethyl acetate-phase fraction of ethanol extract at the concentration of more than 600 μg/ml presents the highest scavenging rate to DPPH·, which is much lower than that of TBHQ and BHT At the concentration of not less than 64μ g/ml, the ethyl acetate-phase fraction exhibits the highest ·OH scavenging rate, followed by the other two fractions having similar ·OH scavenging rate to TBHQ and BHT, and the polysaccharides in turn. At the concentration of 600 μ g/ml, the n-butanol-phase fraction exhibits the highest O2^-· scavenging rate, which is much lower than that of TBHQ and BHT, while the O2^-· scavenging rate of the polysaccharides is significantly lower than that of the three fractions of ethanol extract.