Anti-osteoporosis Activity And Structural Characterization Of A Polysaccharide From Lycium Ruthenicum Murr

In this paper, the polysaccharides of Lycium ruthenicum Murr were prepared after the optimization of extraction processes.The most potent anti-osteoporosis polysaccharide was acheived based on bioactive-guided isolation and its structure was characterized. The obtained results are as follows.(1) The optimization of polysaccharide extraction technology. Accroding to the univariate test and the orthogonal test of solid-liquid ratio, extraction temperature and time, the optimum condition was the solid-liquid ratio of 1:20, extraction time of 2 h and extraction temperature of 80℃. Under this condition, the yield of polysaccharids was 4.51%±0.21.(2) The saparation and purification of homogeneous polysaccharide with anti-osteoporosis activity. The crude polysaccharides of Lycium ruthenicum Murr (LRP) was fractioned by DEAE-Cellulose anion exchange column to give a water-soluble polysaccharide LRPW and three acidic polysaccharides LRP1, LRP2 and LRP3. Among these polysaccharide fractions, LRP2 showed the highest anti-osteoporosis activity. Further, Sephacryl S-500 filtration chromatography of LRP2 gave a homogeneous polysaccharide LRP2A, which remained the anti-osteoporosis activity of LRP2.(3) The physicochemical properties and srructure characterization analysis of LRP2A. Analysis of HPLC, IR., monosaccharide composition determination, methylation test and NMR indicated that LRP2A was a homogeneous acidic polysaccharide with a relative molecular weight of 2.6484×106 Da and uronic acid content of 41.8%, which was composed of Rha, Ara, Glc, Gal and GalA in the molar ratio of 1.00:2.07:0.57:2.59:4.33. LRP2A had a backbone consisting of α-(1→4)-D-GalpA,α-(1→4)-2-Oacetyl-D-GalAMe, α-(1→2,4)-L-Rhap and β-(1→4)-D-Glcp and its branch comprised of β-(1→3)-D-Galp, α-(1→4)-D-GalpA, α-(1→3,5)-L-Araf and α-1-L-Araf.