广东虫草多糖的醇沉及凝胶渗透色谱法表征其分子量分布的研究

Study on ethanol precipitation of Cordyceps guangdongensis polysaccharide and its molecular weight distribution by GPC

采用浓度为30%、50%、70%、90%的乙醇对广东虫草多糖(CGP)进行分级醇沉(GEP)和分步醇沉(SEP)处理。并利用凝胶渗透色谱法(GPC)测定各醇沉组分的保留时间tR、重均分子量Mw、多分散性PD以及各组分的相对含量,以表征不同醇沉方法所得多糖组分的分子量分布。结果表明:不同乙醇浓度醇沉得到的多糖组分的分子量大小有很大差异,且不同分子量范围的多糖在不同醇浓度下的含量也不一致;要获取更多的大分子量虫草多糖,宜采用分步醇沉法,乙醇浓度应从30%逐渐增大到70%;若采用分级醇沉法,则乙醇的浓度应选择在50%～70%。

Ethanol with concentration of 30% ,50% ,70% and 90% were used to treat Cordyceps guangdongensis polysaccharide（CGP） by graded ethanol precipitation（GEP） and stepwise ethanol precipitation（ SEP）.In order to characterize the molecular weight distribution of CGP fractions, retention time （tR）, weight average molecular weight（Mw） polydispersity （PD）and relative content of CGP fractions were obtained by gel permeation chromatography（GPC）.The results showed that the molecular weight of CGP fractions as well as the content of polysaccharide with different molecular weight acquired by ethanol precipitation, varied greatly in different concentrations of ethanol, for the sake of obtaining more CGP with high molecular weight, it was suggested to adopt SEP,with the concentrations of ethanol rising from 30% to 70%, or using GEP with the concentrations of ethanol ranging from 50% to 70%.