Objective: To isolate and purify polysaccharides in Glehniae Radix (GRP) and investigate the structural characterization and in vitro immunological activity of each purified fraction (GRP-1

GRP-2 and GRP-3). Method: GRP was obtained by water extraction and ethanol precipitation method

and then GRP was subjected to protein removal by Sevage method

and then underwent further purification by DEAE cellulose DE-52 column chromatography and Sephadex G-75 column chromatography.The content of GRP and its monosaccharide composition were determined by ultraviolet spectrophotometry (UV) and high performance liquid chromatography combined with derivatization of 1-phenyl-3-methyl-5-pyrazolone (HPLC-PMP)

molecular weight and structural characterization of GRP-1 were carried out by infrared spectrometer (IR) and multi-angle laser light scattering instrument

respectively.The viability of mouse spleen lymphocytes treated with the three fractions was determined by methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay. Result: Three fractions of GRP-1

GRP-2 and GRP-3 were obtained after separation and purification

GRP-1 with a relative molecular weight of 23.01 kDa was a homogeneous polysaccharide

while GRP-2 and GRP-3 were two hetero polysaccharides.The contents of polysaccharides in the three fractions were 96.16%

48.64% and 89.73%

respectively.GRP-1 was composed of mannose

glucuronic acid

rhamnose

glucose

galactose and arabinose in a molar ratio of 81.86∶0.12∶0.17∶1 259.7∶0.54∶0.33.Structure of GRP-1 might have α-glycosidic bond.In the end

in vitro immunological activity results showed that the three polysaccharide components exhibited good immune activity. Conclusion: GRP-1 is a homogeneous polysaccharide with strong immunological activity in vitro.