ISOLATION AND CHEMICAL CHARACTERIZATION OF POLYSACCHARIDES FROM IWATAKE, GYROPHARA-ESCULENTA MIYOSHI

A heteropolysaccharide and a beta-D-glucan were isolated from a lichen , Gyrophora esculenta Miyoshi (Iwatake), by cold water and alkali extr actions, respectively. The chemical properties of purified polysacchar ides were examined by acid hydrolysis, methylation, and GC-MS, The het eropolysaccharide is a highly branched galactomannan-type polysacchari de, containing an alpha-(1-->6)-linked D-mannan backbone, and the gluc an is a linear (1-->6)-beta-D-glucan. With regard to the antitumor act ivity, both the galactomannan and (1-->6)-beta-D-glucan had moderate i nhibition activities on Sarcoma 180, but lower than those of branched (1-->3)-beta-D-glucans.