(594a) Ultrasonic Depolymerization of Schizophyllan

Juan Zeng  Huina Li  Bisheng Zheng*

College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, China 510640

Abstract.

Schizophyllan (SPG), a polysaccharide extracted from Schizophyllum commune Fr., has antitumor and immune activities. However, its physical properties, such as large molecular weight, high viscosity and little solubility in water, make Schizophyllannot be absorbed easily by human body, and not easy to process. In this research, ultrasonic method was applied to depolymerize the Schizophyllan.

Schizophyllan was depolymerized by ultrasonication, and changes in molecular weight and its distribution were observed by gel permeation chromatograghy (GPC). The influences of sonication time, power, temperature, initial SPG concentration were investigated systematically. As the ultrasonication time prolonged, the average molecular weight of ultradonified Schizophyllan (us-SPG) decreased. (Fig. 1). Moreover, when the ultrasonication time was less than 200 minutes, the molecular weight of Schizophyllan decreased fastly, but when the ultrasonication time was more than 200 minutes, the molecular weight of Schizophyllan decreased much more slowly (Fig 3). After SPG was ultrasonic treated for 200 minutes, the molecular was decreased from about 6×10⁶ to 1.5×10⁵Da. The polydispersity of ultrasonified Schizophyllan were between 1.5 and 2.5. The polydispersity randomly changes when the ultrasonication time was less than 200 minutes, but when the ultrasonication time was more than 200 minutes, the polydispersity almost remains 1.7(Fig.3).

*   corresponding author