超滤对当归多糖组分总糖含量和蛋白含量的影响

目的探讨超滤分离当归多糖组分的可行性及其对各组分总糖含量和蛋白含量的影响。方法新鲜岷县当归经80%无水乙醇回流除去脂溶性成分,水提醇沉提取当归粗多糖。将当归粗多糖用蒸馏水溶解,反复冻融除蛋白后,超滤分离出不同分子量的当归多糖组分,并测定各组分的总糖含量及蛋白含量。结果超滤得到分子量分别为10~30 kD,30~300 kD和>300 kD的3个组分,其颜色分别为棕褐色、淡黄色、类白色;总糖含量分别为40.15%,62.12%和80.33%;蛋白含量分别为2.88%,0.98%和0.74%;当归多糖中以分子量>300 kD的当归多糖组分为主,占当归干重的5.48%。结论超滤分离当归多糖,可得到总糖含量较高而蛋白含量较低的主要组分,且操作简单,适于规模化生产。

Effect of Ultrafiltration on Total Sugar Content and Protein Content of Angelica Sinensis Polysaccharide Fractions

Objective To explore the feasibility of isolating Angelica sinensis polysaccharide fractions by ultrafiltration and the effect of ultrafiltration on total sugar content and protein content of these fractions.Methods The fresh plant DangGui from Min-xian county was circumfluenced in 80% ethanol to remove the lipophilic fraction.Rude polysaccharide was obtained by adding ethanol to its concentrated solution extracted in distilled water.The rude polysaccharide was dissolved in distilled water and was deproteinized by repeated freeze thawing,then the different polysaccharide fractions were isolated by ultrafiltration.The contents of the total sugar and the protein of these fractions were determined.Results Three fractions with different molecular weight of 10 ~30 kD,30 ~300 kD and >300 kD were obtained.The colors of these fractions were dark brown,light yellow and off-white color,respectively.The total sugar content was 40.15%,62.12% and 80.33%,respectively.The protein content was 2.88%,0.98% and 0.74%,respectively.The main component of Angelica sinensis polysaccharide was the fraction with large molecular weight(>300KD),which accounted for 5.48% of dry DangGui.Conclusion The main fraction of Angelica sinensis polysaccharide obtained by ultrafiltration has higher total sugar content and lower protein content and the isolation by ultrafiltration is easy to operate,hence,it is suitable to isolate Angelica sinensis polysaccharide fractions in large scale.