铁苋菜多糖体外抗氧化研究

目的:研究不同醇沉浓度下铁苋菜多糖的体外抗氧化活性.方法:用质量浓度为30％,45％,60％,75％,80％的无水乙醇分级沉淀的方法得到不同组分的铁苋菜多糖,分别采用高铁还原法、对二苯代苦味酰基(DPPH·)体系、光照核黄素法、硫代巴比妥酸法比较它们的总还原力(T-AOC)、对二苯代苦味酰基自由基(DPPH·)、超氧阴离子自由基(O2-·)、羟基自由基(·OH)的清除作用及对卵黄脂蛋白脂质过氧化物(LPO)的抑制效果.结果:醇沉浓度为75％时对DPPH·的清除率达到了73.85％,其余各组分多糖都有良好的抗氧化效果,其中对O2-·和·OH的清除作用最为明显,清除率分别达到了92.47％和95.89％,几乎与抗坏血酸的清除作用相当,75％醇沉条件下的多糖对LPO也有较强的抑制作用.结论:铁苋菜各组分多糖都有较强的抗氧化作用.

Antioxidant Activities in vitro of Polysaccharides from Acalypha australis

Objective: To assess the antioxidant activities of polysaccharide from Acalypha australis L. by different ethanol concentration in vitro. Method: The different part of polysaccharide were precipitated by 30%, 45%, 60%, 75%, 80% ethanol. The scavenging rate of the precipitated polysaccharides on (DPPH·)free radical, superoxide anion radical(O₂^-·), hydroxyl radicals(·OH) was investigated by ferric reducing method,DPPH·radical assay,O₂^-·radical assay and thiobarbituric acid method respectively. The total antioxidantive capacity (T-AOC) and the inhibition on lipid peroxide (LPO) of the precipitated polysaccharides were also been determined. Result: The scavenging activities on the DPPH·reached 73.85%. The results showed that T-AOC was enhanced with the increase of polysaccharide concentration. The antioxidantive especially the scavenging activities on the O₂^-·and·OH reached 92.47%, 95.89% respectively at 5 g·L^-1.Furthermore the scavenging effects were as much as that of vitamin C(VC). The inhibition of LPO with the polysaccharide precipitated by 75% ethanol was significantly higher than that of any by other ethanol concentrations. Conclusion: the precipitated polysaccharides from A. australis showed strong antioxidant activities.