Preparation and Immunological Activity Evaluation of Water-soluble β-Glucan from Saccharomyces cerevisiae

The wasted beer yeast ( Saccharomyces cerevisiae) was used as raw material to obtain insoluble p-glucan( SCBG) through acid and alkaline treatment. The water-soluble p-glucan( SCBGs) was prepared by oxidative degradation in the NaOH/urea aqueous solution at low temperature. Four purified components ( SC B Gs -0- 1, SC BGs -1 -1, SC BGs -1 -2 and SC BGs -1 -3) were further obtained by column chromatography. The monosaccharide compositions, molecular weights and chemical structures of four purified components were analyzed by high performance liquid chromatography ( HPLC), high performance gel permeation chromatography -multiple angle laser light scattering( HPGPC-MALLS), nuclear magnetic resonance spectroscopy( NMR) and Congo -red test. Their immunological activities, including the effects of phagocytosis and the release of NO and TNF-a, were studied on macrophage RAW 264. 7. The results showed that all purified component mainly consisted of glucose. They were kinds of 0-1,3/1,6-glucans composed of 0-1,3-glucan as backbone with branches at the site of C6 hydroxyl groups. The molecular weights were determined to be 198000, 960000, 270000 and 18700, respectively. All the components still retained their original supercoil structure except SCBGs-1-3. Four purified components could significantly promote the immunological activity of RAW 264. 7.