Higher Basidiomycota as a Source of Antitumor and Immunostimulating Polysaccharides (Review)

Abstract
Higher Basidiomycota mushrooms arc unlimited sources of anticancer and immunostimulating polysaccharides. Many if not all Basidiomycota mushrooms contain biologically active polysaccharides. The data about mushrooms containing such polysaccharides are summarized. Six hundred and fifty-one species and 7 intraspecific taxa from 182 genera of higher Hetero- and Homobasidiomycetes contain pharmacologically active polysaccharides. Fruiting bodies, culture mycelium, and culture broth are sources of antitumor polysaccharides. The present review includes the data on the chemical structure of primary types of biologically active polysaccharides found in mushrooms. From 10 to 30 fractions of polysaccharides can be extracted from mushroom material, and most of them demonstrated antitumor activity. Special attention is turned to comparative analysis of polysaccharide fraction composition in fruiting bodies and culture mycelia of the same species. It is shown in examples of Agaricus blazei, Ganoderma tsugae, and Grifola frondosa that antitumor polysaccharides obtained from fruiting bodies, culture mycelia. or produced in a culture medium have a different chemical structure, and some polysaccharides developed in pure culture conditions were never found in fruiting bodies. Fractionation procedures for polysaccharide extraction and methods of their activation by chemical modification arc reviewed.