Extraction, antioxidant and antimicrobial activities of Epimedium acuminatum Franch. polysaccharide

Polysaccharides from Epimedium acuminatum were extracted by hot water and optimized with response surface methodology. The optimal conditions of the extraction were determined to be the ratio of water to raw material of 29.61, extraction temperature of 85.67 °C and extraction time of 3.57 h. Under these optimal conditions, the yield of polysaccharide was 8.21%, which was well matched with the predictive yield (8.23%). Moreover, three purified fractions (EAP40-1, EAP60-1 and EAP80-2) were obtained for further chemical analysis, antioxidant activity analysis and antimicrobial activity analysis. EAP40-1 with molecular weight of 138,884 Da showed the best radical scavenging activity. Meanwhile, EAP60-1 with molecular weight of 114,667 Da was found to exhibit significant antihemolytic activity and antimicrobial activity.