Fermentation-mediated variations in structure and biological activity of polysaccharides from Tetrastigma hemsleyanum Diels et Gilg

Variations in the structure and activities of polysaccharides from Tetrastigma hemsleyanum Diels et Gilg fermented by Sanghuangporus sanghuang fungi were investigated. Compare with the unfermented polysaccharide (THDP2), the major monosaccharide composition and molecular weight of polysaccharide after fermentation (F-THDP2) altered dramatically, which caused galactose-induced conversion from glucose and one-third of molecular weight. F-THDP2 had a molecular weight of 1.23 × 104 Da. Moreover, the glycosidic linkage of F-THDP2 varied significantly, a 1, 2-linked α-d-Galp and 1, 2-linked α-d-Manp backbone was established in F-THDP2, which differed from that of 1, 4-linked α-d-Glcp and 1, 4-linked β-d-Galp in THDP2. In addition, F-THDP2 showed a more flexible chain conformation than that of THDP2 in aqueous solution. Strikingly, F-THDP2 exhibited superior inhibitory effects on HeLa cells via Fas/FasL-mediated Caspase-3 signaling pathways than that of the original polysaccharide. These variations in both structure and biological activities indicated that fermentation-mediated modification by Sanghuangporus sanghuang might a promising novel method for the effective conversion of starch and other polysaccharides from Tetrastigma hemsleyanum Diels et Gilg into highly bioactive biomacromolecules, which could be developed as a potential technology for use in the food industry.