Effect of ultrasonic-assisted extraction on antioxidant activity and molecular weight distribution of polysaccharides from Schisandra Chinensis (Turcz.) baill

The molecular weight distribution and antioxidant activity of polysaccharides from Schisandra chinensis (SCP) extracted by hot-water and ultrasonic pretreatment assisted were investigated, including scavenging activities against hydroxyl radical, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide anion. Obvious differences in molecular weight distribution and antioxidant activity between the hot-water extracts and ultrasonic pretreatment assisted extracts were observed. The SCP with ultrasonic pretreatment was degraded causing an increase of fractions. Both of SCP showed a noticeable scavenging activity against hydroxyl radical and DPPH, and the antioxidant activity of SCP, with ultrasonic pretreatment, was higher. However, superoxide anion scavenging activity of SCP was hardly observed.