Isolation, characterization and antioxidant of polysaccharides from Stropharia rugosoannulata

In this study, polysaccharides from Stropharia rugosoannulata were isolated and purified by macroporous adsorption resin and ion exchange chromatography to produce SRP-1 and SRP-2. Preliminary structural characteristics of SRP-1 and SRP-2 were also investigated. Our results showed that SRP-1 was neutral, while SRP-2 was acidic polysaccharides. The molar ratios of monosaccharides in SRP-1 and SRP-2 were different, but glucose was the main monosaccharide. Both α-type and β-type glycosidic linkages were detected in SRP-1, whereas β-constitution was dominant in SRP-2. Both SRP-1 and SRP-2 had a (1 → 6)-α-D-glucan backbone. Furthermore, the antioxidant activities of polysaccharides against ABTS+, DPPH and OH– radicals were determined in vitro. The results indicated that SRP-2 had a stronger antioxidant capacity than that of SRP-1. Our results may be valuable with regard to the utilization of polysaccharides from S. rugosoannulata as potential pharmaceuticals.