Abstract
An antitumor active aqueous extract was obtained from P. ostreatus (Fr.) QUEL. The fractionation by ethanol precipitation, ultrafiltration with molecular sieve membrane and adsorption on DEAE-Sephadex were effective to purify an antitumor active fraction A5 as one spot on a electrophoresis, and to isolate another active fraction A3 and an inactive fraction A6. The active fraction A5 and A3 were constituted of macromolecular polysaccharide, but molecular size of the inactive fraction A6 was smaller than those of the active fractions. The main component sugar was glucose in the fraction A5 and A3, but it was galactose in the fraction A6. The fraction A5 differed from the fraction A3 in a point of including acidic sugar.
