Enzymic preparation of water-soluble chitosan and their antitumor activity.

Water-soluble low-molecular-weight (LMW) chitosan was prepared from enzymatic hydrolysis with efficient hemicellulase. The hydrolysates were separated by ultrafiltration membranes. A separated fraction with Mw more than 5x10(3) and with a degree of deacetylation of 58% was water-soluble in the free amine form. The intraperitoneal injection of LMW chitosan and its N-acetyl product inhibited the growth of sacroma 180 (S180) tumor cells in the mice, and the maximum inhibitory rate reached 64.2%. The oral administration was also effective on decreasing weight of tumor, and the maximum inhibitory rate reached 33.7%. The Water-soluble chitosan with higher Mw than hexamer might have better antitumor activity.