Paper Title
STRUCTURE OF SELENIUM-CONTAINING EXOPOLYSACCHARIDIES ISOLATED FROM THE CULTURE MEDIUM OF MEDICINAL MUSHROOM LENTINULA EDODES

Abstract
Mushroom-derived polysaccharides are compounds of various structure, variable functionality and diverse biological activity. They are active as antioxidants and have antitumor, immune modulating, antibacterial, antimicrobial, antiviral, anti-obesity, hypolipidemic, antidiabetic, and hepato-protective properties, among other activities Polysaccharides obtained from higher fungi affect different types of immune responses and are therefore collectively referred to as Biological Response Modifiers (BRM). In effect, several fungal polysaccharides are used as immunological adjuvants or as a non-invasive form of chemotherapy. In Japan, in the top ten most frequently used drugs with anticancer remains is leninan - - licensed antitumor drug [1]. Lentinan is a highly purity fraction polysaccharides, isolated from fruiting bodies of Lentinula edodes, demonstrating a high level of immune modulatory activity. Antitumor activity has also selenium. The mechanism by which selenium exerts anticancer and immunomodulatory activity differs from Lentinula edodes polysaccharide fractions (β –glukans), but a similar pharmacological effects suggests a possible synergism of these two agents. Selenium added to the medium may enhance the immunomodulatory effect of polysaccharides from the medium culture.The aim of the research was to check the influence of selenium incorporation on the biosynthesis and structure of polysaccharides of fungal origin. Se -containing exopolysaccharide fraction composed mainly of a highly branched 1 -6-α-mannoprotein of molecular weight 4.5 × 106 Da, with 15% protein component was isolated from a post culture medium enriched with selenium of medicinal mushroom Lentinula edodes. The structure of this fraction resembled mannoproteins isolated from yeast and other mushroom cultures, but it was characterized by a significantly higher molecular weight. X-ray absorption fine structure spectral analysis in the near edge region (XANES) suggested that selenium in the Se-exopolysaccharide structure was present mainly at the IV oxidation state. The simulation analysis in the EXAFS region suggested the presence of two oxygen atoms in the region surrounding the selenium [2]. The obtained results will contribute to research on the design of new compounds with immunosuppressive activity.