Chemical analysis of Astragalus mongholicus polysaccharides and antioxidant activity of the polysaccharides

Polysaccharide from Astragalus membranaceus was investigated for its antioxidant potential. Major functional groups of the polysaccharide were analyzed by Fourier transmission-infrared spectroscopy (FT-IR) and gas chromatography (GC). Analysis of the polysaccharide from A. membranaceus revealed four sugars: glucose, galactose, mannose, arabinose. Mannose was the major components, followed by glucose, mannose and arabinose. The presence of aromatic CC bands in the infrared (1600 cm−1) suggested the presence of polyphenols. The intense bands in the infrared O–H and CO regions were attributed mainly to the presence of furan ring. Pharmaceutical experiments showed that administration of Astragalus mongholicus polysaccharides could significantly increase serum and liver antioxidant enzyme activities in mice and decrease peroxidative lipid levels. In conclusion, A. mongholicus polysaccharides may offer good protection against oxidative stress.