Synthesis, characterization and antioxidant activity of selenium modified polysaccharides from Hohenbuehelia serotina

In order to search the optimal pathway to supplement organic selenium and solve the water-solubility of polysaccharides, selenylation was preformed to modify the polysaccharides isolated from Hohenbuehelia serotina (Se-HSP). The physicochemical properties and morphology of Se-HSP were investigated by UV-visible spectrometry, Fourier transform infrared spectrometry (FT-IR), X-ray diffraction spectroscopy (XRD), Circular dichroism spectroscopy (CD), scanning electron microscope (SEM) and atomic force microscope (AFM), respectively. The results suggested that selenium was successfully bound to HSP by esterification reaction. Se-HSP was a non-crystalline substance with the lump structure and smooth and dense surface. The height of Se-HSP was distributed in the range of 35-106 nm. In vitro antioxidant determinations found that Se-HSP possessed the similar/more significant scavenging capacities on ABTS, hydroxyl and superoxide anion radicals as/than the ability of HSP. The present data indicated that selenylation modification could not change the antioxidant activities of HSP in vitro, which also suggested that Se-HSP could serve as a potential antioxidant agent to be used as selenium-complementary nutraceutical.