Antioxidative activities and chemical characterization of polysaccharides extracted from the basidiomycete Schizophyllum commune

Antioxidant properties properties of hot water extract (HWE), hot water extracted polysaccharides (HWP) and hot alkali extracted polysaccharides (HWAE) were obtained from fruiting bodies of the wild basidiomycete Schizophyllum commune. All extracts contained both alpha- and beta-glucans as determined by Megazyme beta-glucan assay kit. Glucose was found by TLC and NMR to be the prevalent monosaccharide in all extracts. Total phenol contents were in descending order of HWP approximate to HWE > HWAE. Median effective concentrations (EC50 values) of antioxidant activities were 8.3 +/- 0.1, 6.9 +/- 0.0 and 8.9 +/- 0.1 mg/mL, and of the DPPH scavenging activity 0.8 +/- 0.0, 0.6 +/- 0.0 and 1.8 +/- 0.0 mg/mL, for HWE, HWP and HWAE, respectively. EC50 values of reducing power were 7.6 +/- 0.1, 7.9 +/- 0.0 and 12.5 +/- 0.1 mg/mL, whereas those of the chelating abilities on ferrous ions were 3.1 +/- 0.0, 4.6 +/- 0.1 and 4.9 +/- 0.1 mg/mL The EC50 values of the antioxidant activity, of the DPPH scavenging, and of the reducing power were correlated with total polysaccharide as well as with total phenol content. The antioxidant activities of all the extracts may be caused by both polysaccharides and polyphenols or by a complex of both. (C) 2011 Elsevier Ltd. All rights reserved.