ANTI-TUMOR ACTIVITY OF CARBOXYMETHYLGLUCANS OBTAINED BY CARBOXYMETHYLATION OF (1-]3)-BETA-D-GLUCAN FROM ALCALIGENES-FAECALIS VAR MYXOGENES IFO-13140

Soluble carboxymethylglucans were obtained by carboxymethylation of insoluble (1→3)-β-d-glucan from Alcaligenes faecalis var. myxogenes IFO 13140. Carboxymethylglucan with DS 0.47 (DS, number-average degree of carboxymethyl groups substituted per anhydroglucose unit) strongly inhibited growth of sarcoma 180 solid-type tumor when injected daily i.p. (3-40 mg/kg) or i.v. (5 mg/kg) for 10 days. It also strongly inhibited growth of Sarcoma 180 when injected i.p. in a single dose of 20-200 mg/kg 7 days after tumor transplantation. The DS of carboxymethylglucans was found to be closely correlated with their antitumor activity, compounds with a DS of about 1.0 per glucose residue having less activity. This chemically modified glucan seemed to have a host-mediated action, because it had no cytotoxic effect in vitro and because it was effective when injected before tumor transplantation. © 1979.