Abstract:

In this study, the effect of ethanol concentration on the yield, purity, physicochemical properties and antioxidant
activity of intracellular polysaccharides (IPs) isolated from Phellinus igniarius was analyzed. Results indicated that with an
increase in ethanol concentration, the yield of crude polysaccharides increased, but polysaccharide content of the precipitated
crude polysaccharides changed irregularly. Each of the IPs precipitated by different concentrations of ethanol contained
xylose, mannose, galactose and glucose. Scanning electron microscopy (SEM) images showed that the IPs precipitated by
low concentration (65%、75%、85%) of ethanol presented a uniform spherical shape, whereas those precipitated by high
concentration (95%) of ethanol were clustered into large flakes. IPs of Phellinus igniarius had obvious antioxidant activity
in vitro in a dose-dependent manner and the IPs precipitated by 95% ethanol had the best scavenging activity against DPPH,
hydroxyl and ABTS+ free radicals and the strongest ferric reducing antioxidant power.

Key words: Phellinus igniarius, intracellular polysaccharides (IPs), physicochemical properties, antioxidant activity in vitro