Isolation and Antioxidant Activity of Water-soluble Acidic Polysaccharide from Prunella vulgaris Linn

An acidic polysaccharide with antioxidant activity was obtained from Prunella vulgaris Linn through sequential steps of water extraction and alcohol precipitation,then decolorization and deproteinization by HZ-820-type unpolar resin adsorption,and finally purification.3-Hydroxydiphenyl-sulfuric acid and barium chloride-gelatin turbidimetric methods were used to determine contents of galacturonic acid and sulfate in the polysaccharide,and the results were(58.85 ± 0.46)% and(7 ± 0.52)%,respectively.Ultraviolet and infrared(IR) spectral analyses indicated that the monosaccharide composition of the polysaccharide consisted of galacturonic acid,xylose,glucose,rhamnose,and galactose and it belonged to the nonglycoprotein family.Moreover,this polysaccharide revealed strong scavenging activities against hydroxyl free radicals and DPPH free radicals.