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

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。

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

Objective: To determine such molecular characteristic parameters as absolute molecular weight, molecular weight distribution, root-mean-square turning radius(R_g) and polydispersity index(Mw/Mn) of four components contained in Hedysari Radix polysaccharide 3(HPS-3) and map weight-average molecular weight(Mw) with root-mean-square turning radius(R_g), 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^-1NaNO₃ contained 0.02% NaN₃ as the mobilephase, Ultrahydrogel^TM1000 connected in series with Ultrahydrogel^TM500. Result: Among the four components of HPS-3, HPS-3-C showed the highest weight average molecular weight of 1.986×10⁵ g·mol^-1, followed by HPS-3-B 1.113×10⁵ g·mol^-1 and HPS-3-D 8.457×10⁴ g·mol^-1, HPS-3-A showed the lowest weight average molecular weight of 1.223×10⁴ g·mol^-1 but 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 components contained in HPS-3 and their relationship with bioactivity.