Supercritical CO2 extraction, structural analysis and bioactivity of polysaccharide from Grifola frondosa

Polysaccharide was extracted from Grifola frondosa with supercritical CO2 technology. The optimum extraction conditions for the highest yield were determined by Box-Behnken design: the pressure was 34.5Mpa, the extraction temperature was 36.7 ℃, the extraction time was 116.3 min and the ratio of entrainer to raw material was 2.86 mL/g, to give a polysaccharide yield of 4.61 %. The polysaccharide from G. frondosa was purified with ionic liquid. The polysaccharide was characterised as a predominantly heteropolysaccharide composed of different monosaccharides with a β - type structure. The anti-tumour and antibacterial experiments on the polysaccharide in vitro showed that the polysaccharide had marked anticancer and antibacterial effects.