Abstract:
To investigate distribution and antioxygenic activity of different molecular weight polysaccharide in A. potaninii Korsh, the polysaccharides with different molecular weight were separated into 6 ratings, and the antioxygenic activity of the separated polysaccharides in scavenging free radical of 2,2-diphenyl-1-picrylhidrazyl (DPPH) were studied. By dialysis with a sack of dialysis (the size range of molecular weight, 8 000—15 000), the polysaccharids were divided into two parts (the higher and lower molecular weight polysaccharide). Using the DEAE-cellulose column chromatographic separation, the higher molecular weight polysaccharides were eluted by NaCl aqueous in different concentration, and 3 ratings (APK1, APK2 and APK3, 842 100, 425 800 and 22 400 in molecular weight) were obtained. By the precipitation separation with ethanol in different concentration, lower molecular weight polysaccharides were divided into another 3 ratings (APK4, APK5 and APK6, 12 500, 6 500 and 3 900 in molecular weight).The results indicated that the ratio of 6 ratings was APK1(842 100)∶APK2(425 800)∶APK3(22 400)∶APK4(12 500)∶ APK5(6 500)∶APK6(3 900)= 1∶14∶22∶92∶706∶233（w/w）, illustrating that APK5(6 500) in total polysaccharide is dominant. The results from antioxygenic activity of different molecular weight polysaccharide indicated that a lower molecular weight polysaccharide (APK5, 6 500 in molecular weight) possesses strong capacity in scavenging free radical of DPPH, IC50 is 0213 mg/ mL.
