[Study on molecular characteristics of four components contained in Hedysari Radix polysaccharide by gel permeation...

To determine such molecular characteristic parameters as absolute molecular weight, molecular weight distribution, root-mean-square turning radius (Rg) 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 (Rg), in order to calculate conformations of the four components at solution state.

The gel permeation chromatography-multi angle laser light scatting (GPC-MALLS) was adopted, with 0.1 mol x L(-1) NaNO3 contained 0.02% NaN3 as the mobilephase, Ultrahydrogel 1000 connected in series with Ultrahydrogel500.

Among the four components of HPS-3, HPS-3-C showed the highest weight average molecular weight of 1.986 x 10(5) g x mol(-1), followed by HPS-3-B 1.113 x 10(5) g x mol(-1) and HPS-3-D 8.457 x 10(4) g x mol(-1) HPS-3-A showed the lowest weight average molecular weight of 1. 223 x 10(4) g x 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.

The results provided necessary basis for further studies on molecular characteristics of the four components contained in HPS-3 and their relationship with bioactivity.