RESUMO
Obejctive:To study the extraction, separation, physical and chemical properties and antioxidant activity of the crude polysaccharide from Alhagi sparsifolia Shap.stem-branch.Methods: The crude polysaccharide from Alhagi sparsifolia Shap.stem-branch was extracted by ethanol subsiding method .The total sugar content was determined by phenol-sulfuric acid method and the pro-tein content was determined by coomassie brilliant blue method .The content of uronic acid was determined by carbazole sulfuric acid method and the monosaccharide composition and the relative molar ratio were determined by GC .The antioxidant activities in vitro were evaluated by determining the reducing power of polysaccharide from Alhagi sparsifolia Shap stem-branch and its removal ability to 1,1-diphenyl-2-trinitrophenylhydrazine ( DPPH) radicals and hydroxyl radicals .Results: The total sugar content of crude polysaccharide from Alhagi sparsifolia Shap.stem-branch was 73.2％, and uronic acid accounted for 27.2％of the total sugar content of crude poly-saccharide.The content of protein was 17.6％.The crude polysaccharide from Alhagi sparsifolia Shap .stem-branch was composed of Rha, Ara, Xyl, Man, Glc, Gal, GlcA and GalA, and the relative molar ratio was 1.05:1.00:1.25:0.52:3.05:1.31:0.47:4.78. The reducing power of the polysaccharide from Alhagi sparsifolia shap.stem-branch and the clearance rate on DPPH radicals and hy-droxyl radicals increased with the increase of polysaccharide concentration .Conclusion:The crude polysaccharide from Alhagi sparsi-folia Shap.stem-branch was extracted , and the physical and chemical properties and antioxidant activity in vitro were studied, which provide foundation for the further investigation and comprehensive utilization of Alhagis parsifolia Shap.stem-branch.