Abstract: [Objective]To characterize the degradation process of polysaccharides isolated from the sclerotium of Inonotus obliquus in artificial gastric juice and artificial intestinal juice. [Method]The artificial gastric juice and artificial intestinal juice was used to degrade the polysaccharides extracted from the sclerotium of Inonotus obliquus with hot water by using semi-bionic method. The sugar content and the reducing sugar content of the sclerotium polysaccharides during and after the degradation process were determined by the phenol-sulfuric acid method and DNS method, respectively. The molecular weight of the degradation products was assessed by high-performance liquid chromatography (HPLC). [Result]The sugar content of the polysaccharides extracted from the sclerotium of Inonotus obliquus was decreased continuously with the prolonged degradation time in artificial gastric juice and intestinal juice, and the change of reducing sugar content was not significant. The retention time of the degraded sclerotium polysaccharides in HPLC was not significantly different from that of the undegraded sclerotium polysaccharides, which indicated that the molecular weight of polysaccharides had no significant change before and after the degradation. [Conclusion]The polysaccharides isolated from the sclerotium of Inonotus obliquus in artificial gastric juice and artificial intestinal juice degraded neither by breaking the glycosidic bond at the end of the sugar chain nor by breaking that at the branch chain one by one, but by fracturing the sugar chain of the polysaccharides into short chains.

Key words: Inonotus obliquus, polysaccharides from sclerotium, semi-biomimetic degradation