Influence of different bond types and polymerization degrees of glucose polymers on the fermentation of Inonotus obliquus for the production of hypoglycemic activity polysaccharides.

From the paper

Abstract

This research aimed to investigate the impact of different glycosidic polymers, such as maltose, cellobiose, starch, and β-glucan, on the production of bioactive polysaccharides via deep liquid fermentation using Inonotus obliquus (I. obliquus). The focus was on their potential role as α-glucosidase inhibitors in diabetes treatment. The polysaccharides were assessed based on the induction of sugar components and the resulting α-glucosidase inhibitory rate (AGIR). The findings indicated that β-glucan was the most effective in enhancing polysaccharide production, followed by starch, maltose, and cellobiose. β-Glucan resulted in the highest AGIR increase (52.7 %), a 2.01-fold improvement compared to the control. After isolation and purification from the β-glucan fermentation products, the polysaccharide DPG-2 was identified as β-glucan, with a molecular weight of 17.02 kDa and an IC50 value of 91.71 μg/mL, surpassing that of acarbose. Structural analysis revealed that the enhanced AGIR of DPG-2 was primarily attributed to a greater proportion of β(1 →3) and β(1 → 6) glycosidic bonds compared to the control, which were crucial for its elevated AGIR. Under neutral to slightly alkaline conditions, DPG-2 formed a structured triple helix and exhibited protein binding. These results highlight the potential of β-glucan polysaccharides from I. obliquus as promising candidates for diabetes therapy.