Structural elucidation and antioxidant activity of a water-soluble polysaccharide from the fruit bodies of Bulgaria inquinans (Fries)

► Polysaccharide from non-lichenized ascomycete contained β-Galf and α-(1 → 6)-mannan core. ► The above polysaccharide (BIWS-4b) was tested to have antioxidant activity. ► OH-scavenging and Fe2+-chelating abilities of BIWS-4b are better than similar polysaccharides.