Structural characteristics and hypoglycemic activity of polysaccharides from Coprinus comatus

The effects of grinding process on the extraction of polysaccharide from Coprinus comatus were investigated. The extracts named as CCPF and CCPP were obtained from the fragments and the powder of the C. comatus fruiting bodies, respectively. The comparison on the chemical analysis of CCPF and CCPP showed that reducing particle size could dramatically improve the extract yield and content of polysaccharide fractions, which resulted from the increasing of high molecular weight (Mw) fractions. The high Mw fraction CCPP-1 was isolated using the ethanol precipitating method. Its molecular weight was estimated to be 2.44×107 g/mol by high-performance size exclusion chromatography-multi angle laser light scattering (HPSEC-MALLS). CCPP-1 took compact conformation in aqueous solution. Structural analysis showed that CCPP-1 was α-d-(1→4)-glucan with branches at C-6 consisting of non-reducing terminal approximately every fourteen residues. The hypoglycemic activity study revealed that CCPP-1 had no effect on reducing blood sugar. The crude polysaccharide extracts CCPF showed significant hypoglycemic activity.