Preparation of bioactive water-soluble pachyman hydrolyzed from sclerotial polysaccharides of Poria cocos by hydrolase

Water-soluble pachyman (WSP) was prepared by enzymic hydrolysis of pachyman extracted from Poria cocos sclerotium using a 0.5 mol l 1 NaOH solution at the optimized conditions of 55 1C, pH 4, 4% pachyman, 2 U ml 1 hydrolase, and a hydrolysis time of 6 h. Two WSP fractions, WSP-1 and WSP-2, were prepared using SephadexG-100 to separate WSP. Both fractions were of the b-(1-3)-D-dextran structure and were only composed of glucose with no nucleic acid and protein. The composition was analyzed by ultraviolet spectroscopy and infrared spectroscopy, Congo Red reaction analysis and monosaccharide composition analysis. The effects of WSP (Mw 1.75 105), WSP-1 (Mw 1.86 106) and WSP-2 (Mw 3.58 104) on the proliferation of S180 tumor cells in vivo and in vitro were studied. The inhibitory ratios of the three tested WSPs on the proliferation of S180 tumor cells at 0.5 lg ml 1 in vitro were found to be 4.0±0.6, 2.2±0.1 and 2.6±0.1%, respectively, and the inhibitory ratio of carboxymethyl pachyman (CMP), which was used as a control, was 0.3±0.4%. WSP, WSP-1 and WSP-2 also exhibited significant inhibition on S180 tumor cells in vivo at a dose level of 200 mg kg 1 day 1, with their inhibition ratios found to be 43.94, 41.57 and 39.81%, respectively. Furthermore, the three tested WSPs had no obvious effect on the weight of mice, whereas the administration of CMP resulted in a decrease in mice weight at the tested concentration. Polymer Journal (2010) 42, 256–260; doi:10.1038/pj.2009.329; published online 6 January 2010