Isolation, purification, and structure of components from acidic polysaccharides of pleurotus ostreatus (Fr.) Quél.

Abstract

Isolation of an antitumor component from polysaccharide fraction A 5 of some Basidiomyces was achieved by column chromatography on Sephadex G-200. A detection method based on the specific rotatory characteristics of the polysaccharide was applied to estimate components in effluent fractions from the chromatography, and it was confirmed that a series of eluates having similar specific rotation was made up of homogeneous polysaccharide. Three components (H 51, H 52, and H 53) were isolated, in chromatographically pure state, from fraction A 5. Component H 51 consisted of a skeleton of β-(1→3)-linked glucose residues, probably having branches of galactose and mannose residues, and also containing acidic sugars. Component H 53 had a main structure similarly consisting of β-(1→3)-linked glucose residues and a larger proportion of acidic sugar than H 51. Component H 52 was a heteropolysaccharide made up of α-linked galactose and mannose residues. Components H 51 and H 53 had a higher and a lower molecular weight, respectively, than H 52. The only antitumor-active component was H 51.