The purpose of our study is to reveal the influence rule of ultrasonic power on the structure and activity of ophiopogon japonicus polysaccharides. Five kinds of ultrasonic power are selected to extract polysaccharides from ophiopogon japonicus root. Precipitation by quaternary ammonium salt was applied to isolate the five kinds of polysaccharides extracted by ultrasound respectively. The polysaccharides of AP1 and AP3 were obtained. Then high performance liquid chromatography and gas chromatography was applied to detect molecular weight distribution and monosaccharide composition of five kinds of polysaccharide AP1 and AP3. Our results show that:as the ultrasonic power increasing larger molecular weight polysaccharides were obtained, however with the further increase of ultrasonic power a large number of high molecular weight polysaccharides are degraded into small molecular weight polysaccharide, and this phenomenon is mainly induced by large molecular weight polysaccharide molecular weight cutting in half. Gas chromatography studies show that: with small ultrosonic power it is a hard work to extract monosaccharide components which are steadily embedded in ophiopogon japonicus raw material. However with the increase of ultrosonic power rhamnose, arabinose and are extracted. Antioxidant activity shows that increasing the ultrasonic power, antioxidant activity of ophiopogon japonicus polysaccharide increased to the maximum and then decreased. The antioxidant activity was highest when the ultrasonic power was 400W. Therefore, ultrasonic power on the structure and activity of ophiopogon japonicus polysaccharide has significant influence.

ultrasonic power; ophiopogon japonicus polysaccharide; structure; antioxidant activity