凝胶渗透色谱-多角度激光散射联用技术研究红芪多糖中4个组分分子特征

Study on molecular characteristics of four components contained in Hedysari Radix polysaccharide by gel permeation chromatography-multi angle laser light scatting technology(GPC-MALLS)

目的:测定红芪多糖3(HPS-3)中4个组分的绝对分子量,相对分子质量分布,均方根旋转半径(Rg),多分散系数(Mw/Mn)等分子特征参数,以均方根旋转半径(Rg)对重均分子量(Mw)作图,计算4个组分在溶液状态的构象。方法:采用凝胶渗透色谱-多角度激光散射(GPC-MALLS)联用技术,流动相为含0.02%NaN3的0.1 mol.L-1NaNO3溶液,Ultrahydro-gelTM1000,500色谱柱串联。结果:HPS-3的4个组分中,HPS-3-C的Mw最大(1.986×105g.mol-1);其次为HPS-3-B(1.113×105 g.mol-1)和HPS-3-D(8.457×104 g.mol-1);HPS-3-A的Mw最小(1.223×104 g.mol-1),而Rg最大(55.5 nm)。HPS-3-D相对分子质量分布范围最广,Mw/Mn 2.543。在流动相中,HPS-3-A为球型构象,HPS-3-C为无规则线团构象,HPS-3-B和HPS-3-D则均为高枝化度结构。结论:为进一步研究HPS-3中4个组分分子特征与其生物活性的关系提供必要依据。

Objective： To determine such molecular characteristic parameters as absolute molecular weight, molecular weight distribution, root-mean-square turning radius （Rs ） and polydispersity index （Mw/Mn） of four components contained in Hedysari Ra- dix polysaccharide 3 （ HPS-3 ） and map weight-average molecular weight （Mw） with root-mean-square turning radius （ Rs ） , in order to calculate conformations of the four components at solution state. Method： The gel permeation chromatography-multi angle laser light scatting （GPC-MALLS） was adopted, with 0. 1 mol · L^-1 NaNO3 contained 0.02% NaN3 as the mobilephase, UltrahydrogelTM 1000 connected in series with UltrahydrogelTM500. Result： Among the four components of HPS-3, HPS-3-C showed the highest weight aver- age molecular weight of 1. 986 ×10^5g·mol^-1 , followed by HPS-3-B 1. 113×10^5g·mol^-1 and HPS-3-D 8.457 ×10^5g·mol^-1HPS-3-A showed the lowest weight average molecular weight of 1. 223 ×10^5g·mol^-1but the highest square radius of gyration, that is 55.5 nm. HPS-3-D had the widest range of molecular weight distribution in four components, with the polydispersity index （Mw/Mn） of 2. 543. In the mobile phase, HPS-3-A was globular structure, HPS-3-C was random coil , HPS-3-B and HPS-3-D were both highly branched structure. Conclusion： The results provided necessary basis for further studies on molecular characteristics of the four compo- nents contained in HPS-3 and their relationship with bioactivity.