微波辅助盐酸/过氧化氢降解浒苔多糖及其抗氧化活性

Degradation of polysaccharide from Enteromorpha prolifera with hydrochloric acid and hydrogen peroxide assisted by microwave and its antioxidant activity

以自制的浒苔多糖为原料,采用微波辅助盐酸/过氧化氢降解浒苔多糖。以对·OH清除率为指标,利用单因素试验和正交试验进行降解工艺优化。最佳工艺条件为:在1 mol/L的盐酸溶液中,反应10 min、温度50℃、微波功率900 W、30%过氧化氢加入量5%。降解浒苔多糖得率77.88%,对·OH清除率61.51%。降解前后,浒苔多糖对·OH清除率的IC_(50)分别为1.059 mg/m L和0.348 mg/m L,降解浒苔多糖的抗氧化活性明显高于未降解浒苔多糖。利用凝胶色谱测得浒苔多糖的平均分子质量84.02 ku,降解浒苔多糖的平均分子质量53.59 ku。IR和NMR结构分析显示降解前后多糖的单糖组成均为α-D-葡萄吡喃糖,且降解后多糖的基本结构和活性基团没有被破坏。

Taking the scavenging capability to ·OH as indicator,polysaccharide from Enteromorpha prolifer was degraded by HCl and assisted by microwave.By single factor and orthogonal experiments,the optimal degradation conditions were 900 W at 50 ℃ for 10 min with 5% H2O2 in 1 mol/L hydrochloric acid solution.Under these conditions,the yield of degradation product was 77.88%,and its hydroxyl radical scavenging rate was 61.51%.Compared to the intact polysaccharide,the degradation product had significantly higher antioxidant activity with an IC50 of 0.348 mg/m L compared to 1.059 mg/m L for the intact polysaccharide.Moreover,using HPGPC,their average molecular weights were 84.02 ku and 53.59 ku,respectively.From the results of IR and NMR spectroscopy,their constitutional units were made up of α-D-glucopyranose,and the active groups had not been damaged.