硫酸化修饰对红枣多糖结构及抗氧化活性的影响

Effect of sulfate modificate on the structure and antioxidant activity of jujube polysaccharide

目的:探究纯化红枣多糖ZJP-1和硫酸化红枣多糖S-ZJP-1的结构和抗氧化活性之间的关系。方法:以残次红枣为原料,经热水浸提、DEAE-52离子交换色谱及Sephadex-200葡聚糖凝胶柱层析纯化得到纯化红枣多糖(ZJP-1),通过氯磺酸—吡啶法硫酸化修饰获得红枣多糖硫酸化衍生物(S-ZJP-1)。结果:ZJP-1和S-ZJP-1均由葡萄糖、阿拉伯糖、半乳糖3种单糖组成,但是比例有所不同。两种多糖具有多糖特征吸收峰,S-ZJP-1具有硫酸基的特征吸收峰,表示硫酸化修饰成功。ZJP-1和S-ZJP-1不具有三股螺旋结构,表观呈片状结构。活性试验结果证实多糖ZJP-1和S-ZJP-1对DPPH自由基具有显著的清除活性,并具有一定的还原力,当多糖质量浓度达到0.5 mg/mL时,DPPH自由基清除活性分别为40.4%和47.6%,还原力分别为0.419和0.531。结论:硫酸化修饰的红枣多糖抗氧化活性更高,是一种良好的天然抗氧化剂。

Objective:This study aimed to explore the relationship between the structure and antioxidant activity of purified red date polysaccharide ZJP-1 and sulfated red date polysaccharide S-ZJP-1.Methods:Using remnant jujube as raw material,jujube polysaccharide(ZJP-1)was purified by hot water extraction,and then separated by DEAE-52 ion exchange chromatography and Sephadex-200 dextran gel column chromatography.Thereafter,red jujube polysaccharide sulfated derivative(S-ZJP-1)was obtain through chlorosulfonic acid-pyridine sulfated modification.Results:Both ZJP-1 and S-ZJP-1 are composed of three monosaccharides:glucose,arabinose,and galactose,but the ratios are different.The two polysaccharides had characteristic absorption peaks of polysaccharides,and S-ZJP-1 had characteristic absorption peaks of sulfate groups,indicating that the sulfation modification was successful.No triple helical structure was found in ZJP-1 or S-ZJP-1,while a sheet-like structure was detected.The results of the activity test confirmed that the polysaccharides ZJP-1 and S-ZJP-1 had significant scavenging activity on DPPH free radicals with reducing ability.When the mass concentration of the two kinds of polysaccharide was 0.5 mg/mL,the DPPH free radical scavenging activities were 40.4%and 47.6%,and the reducing ability is 0.419 and 0.531,respectively.Conclusion:The sulfate-modification jujube polysaccharide has higher antioxidant activity and is a good natural antioxidant.