Abstract
Deproteinization was comparatively employed for the purification of crude exopolysaccharide (CEP) of Ganoderma sinense mycelium. Results showed that ammonium sulfate (70% saturation) salting out could remove 95% proteins of CEP, whereas 20% trichloroacetic acid precipitation was best with a polysaccharide loss less than 20%. Protein-bound polysaccharides could be removed by both methods, and polysaccharides with high molecular weight dominated in the lost polysaccharides. Through anion-exchange chromatography, a highly branched α-(1→6)-D-mannan and a protein-bound heteropolysaccharide were prepared from CEP. Both fractions could inhibit the in vitro proliferation of tumor cells BEL-7402, and induce TNF-α secretion of murine splenocytes.