Structure elucidation and antioxidant activity of a novel alpha-(1-->3),(1-->4)-D-glucan from Aconitum kusnezoffii Reichb.

Aconitum kusnezoffii Reichb. has been used as traditional Chinese medicine over the last 2500 years, but its polysaccharides have been paid little attention by now. In the present study, a hot alkali extracted polysaccharide (AKP) from A. kusnezoffii Reichb. was characterized to be an alpha-(1-->3),(1-->4)-D-glucan with Mw 1.4 x 10(5) Da, of which (1-->3)-linked and (1-->4)-linked alpha-Glcp residues were in a ratio of 1:7. In vitro antioxidant testing indicated that AKP had significant ferrous ion-chelating ability, reducing power and scavenging effects on DPPH radical, hydroxyl radical, superoxide anion, H2O2 and self-oxidation of 1,2,3-phentriol, suggesting that it should be explored as a novel natural antioxidant.