乙醇分级法分离南酸枣多糖及其理化性质和抗氧化性研究

李景恩; 赵颖; 陈卓

doi:10.13386/j.issn1002-0306.2017.02.016

乙醇分级法分离南酸枣多糖及其理化性质和抗氧化性研究

Physicochemical properties and antioxidant activities of polysaccharides isolated from Choerospondias axillaris by ethanol fractional precipitation method

摘要

摘要: 本文依次采用60%（v/v）和80%（v/v）的乙醇溶液对南酸枣粗多糖进行分级沉淀,分别获得两个组分CAP-60和CAP-80,上清液部分冷冻干燥后标记为CAP-S。采用分析化学法测得三个组分的中性糖、糖醛酸及蛋白质含量,并应用红外光谱仪分别检测各组分的光谱学特征。最后通过DPPH自由基和羟基自由基清除及还原力实验,检测南酸枣多糖各组分的抗氧化活性。结果表明CAP-60、CAP-80和CAP-S的总糖含量分别为94.95%±2.51%、71.50%±2.02%、35.18%±2.06%,且三个组分中均含有糖醛酸,与红外光谱图中1700¹600 cm-1附近的吸收峰一致。在上述三种抗氧化体系中,CAP-S均表现出最强的抗氧化能力,但在最高浓度下仍略次于抗坏血酸。

Abstract: Two new polysaccharides( CAP-60 and CAP-80) were fractionated from the crude polysaccharides of Choerospondias axillaris by 60%( v / v) and 80%( v / v) ethanol,successively. A third fraction CAP- S was obtained from the supernatant by freeze drying. Neutral sugar,uronic acid and protein contents were determined by analytical chemistry methods,and their spectral characteristics were determined by FTIR spectrometer.DPPH free radical and hydroxyl radical scavenging test,as well as reducing power were applied to evaluate the antioxidant activities of these three fractions.The results indicated that the total sugar of CAP-60,CAP-80 and CAP- S were 94.95% ± 2.51%,71.50% ± 2.02% and 35.18% ± 2.06%,respectively. They all contained uronic acids in their structures,which were consistent with the absorption peaks of 1700 ~1600 cm- 1in the infrared spectrum.What's more,CAP- S possessed the strongest antioxidant activities among these three antioxidant systems above,but was still inferior to ascorbic acid even under the highest concentration.