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It was postulated that fractions enriched in selenium (Se) isolated from Lentinula edodes mycelium polysaccharide might possess higher biological activity than the non-enriched fractions currently used to treat cancer. In order to obtain Se-enriched mycelial preparations, L. edodes cultures were cultivated in media enriched with sodium selenite. In order to determine whether the concentration of Se in the culture medium affected the biosynthesis and composition of cell wall and cell membrane, concentrations of the exopolysaccharide (EPS), chitin, and sterol (ergosterol) were measured in harvested mycelia. In addition, the relationship between Se accumulation and content of polyphenols and vitamin D(2) in L. edodes mycelium was examined. The effects of Se levels on the mycelium cell composition were determined in culture media enriched with Se at concentrations ranging from 0 to 30 microg/ml. In each culture mycelial growth, total Se and Se distribution were determined between mycelial fractions of different polarity. The EPS, polyphenolics, and ergosterol content in harvested mycelia rose in proportion to Se concentration in the culture medium. The chitin content in mycelia increased with Se concentrations in the range 0-5 microg/ml, but at higher concentrations chitin levels decreased. Data showed that Se in culture medium exerted potent effects on the composition of the mushroom cell wall and semipermeable membrane, and on the content of polyphenolics that are involved in detoxification processes. Our findings indicate the optimal concentration of Se required in the culture medium for maximal yield of immunostimulatory-active selenated exopolysaccharides.

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The two-stages studies of structure–activity relationship for model ligands of 5HT1A, 5HT2A, and D2 receptors were performed. On the first stage, the pharmacophores of two potential ligands of known in vitro binding to 5HT1A, 5HT2A, D2 receptors and model pharmacophore of strongly interacting D2 receptor ligands were found and their parameters were related to affinity data. The analyzed parameters were hydrophobic, hydrophilic, aromatic, donor and acceptor of proton centers. The geometry of spatial distribution of these properties was also investigated in comparative analysis. The studied, model compounds were two 3β-acylamine derivatives of tropane. The second stage includes docking of studied compounds to D2 receptor model and the comparison of its quality with in vivo binding data. The obtained results are consistent with in vitro binding data and applied procedure accurate estimates the affinity of potential ligands to D2 receptors.