Antioxidant activity of Phellinus igniarius fermentation mycelia contributions of different solvent extractions and their inhibitory effect on α-amylase

Phellinus spp. have historically been used as traditional medicines to treat various diseases owing to their antioxidant, antitumor, and antidiabetic activities. Polysaccharides exhibit antidiabetic activity. In the present study, the polysaccharide contents of four Phellinus strains were compared. Phellinus igniarius QB72 possessed higher polysaccharide production, stronger 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, and α-amylase inhibitory activity. The three polysaccharides were sequentially extracted and partially purified from the fermentation mycelia using hot water, 1 % (NH4)2C2O4, and 1.25 M NaOH. Hot water extract polysaccharides exhibited higher DPPH radical scavenging and strong inhibitory activity against α-amylase with an IC50 value of 6.84 ± 0.37 mg/mL. The carbohydrate content of A1 (approximately 17457 Da) was approximately 88.28 %. The α-amylase inhibitory activity IC50 was decreased (3.178 ± 0.187 mg/mL) after DEAE water elution. P. igniarius QB72 hot-water extracts of partially purified polysaccharides have great potential as α-amylase inhibitors in food and medication-assisted additives.