Optimum Isolation and Structural Analysis of Polysaccharide from the Fruiting Bodies of Coprinus comatus

Abstract:

Optimum technique of isolation and purification of Coprinus comatus polysaccharides was investigated by orthogonal tests. DEAE-Sepharose F. F. and gel-filtration chromatography were used to separate and purify the Coprinus comatus polysaccharides, and get the homogeneous polysaccharide CC30w-1.The structure of CC30w-1 was studied with chemical and spectral methods. The results showed that the optimum conditions for the isolation was as follows： times of extraction 3, time 1.5h, temperature 95℃, material to water ratio 1∶12.The optimum deproteinization condition is that crude polysaccharide solute in the mixed solvent of chloroform and n-butanol (3∶1) whose volume 3 times that of the former, the reaction time and times of purification were 20 minutes and 7 times, respectively. CC30w-1 molecular weight was estimated to be 1.94×10⁴ by HPLC. HPAEC showed CC30w-1 was composed of fucose and galactose in molar ratios of 1∶4.02. Methylation analysis and NMR data showed that it possess a pentasaccharide repeating unit have a backbone of (1→6)-linked galactose residues, and is substituted at 2-position by fucose residue.

Key words:Coprinus comatus, Orthogonal tests, Isolation and purification, Structural analysis