Extraction, isolation, characterisation, antioxidant and anti‐fatigue activities of Pleurotus eryngii polysaccharides

Summary Pleurotus eryngii polysaccharide (PEP) was obtained using hot water extraction and ethanol precipitation. Three purified polysaccharide fractions (namely PEP1‐A, PEP2‐A and PEP3‐A) were obtained from PEP using DEAE‐cellulose‐52 chromatography and a gel permeation Sephadex G‐100 column. Firstly, this paper examined the characterisation of PEP1‐A, PEP2‐A and PEP3‐A. The corresponding molecular weights were 5.378 × 105, 9.506 × 106 and 4.975 × 105 Da, respectively. PEP1‐A, PEP2‐A and PEP3‐A had similar monosaccharide compositions. PEP1‐A was β‐configuration, and PEP2‐A and PEP3‐A were α‐configuration. PEP1‐A, PEP2‐A and PEP3‐A had pyran‐type rings, (1 → 3) glucose and (1 → 6) galactose linkages. Secondly, PEP, PEP1‐A, PEP2‐A and PEP3‐A possessed antioxidant activities, and PEP was best. Therefore, only PEP was used to study its anti‐fatigue activity in vivo. The result proved that PEP had anti‐fatigue activity. PEP could be used as a valuable natural food supplement for preventing anti‐fatigue or functional food.