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.

Wang L ，Li X ，Wang B 《-》

Effect of extraction method on structure and antioxidant activity of Hohenbuehelia serotina polysaccharides.

The impacts of four extraction methods (hot water, enzyme assistance, ultrasonic assistance and ultrasonic-enzyme assistance) on the extraction yields, preliminary structure and antioxidant activities of the Hohenbuehelia serotina polysaccharides (HW-HSP, EA-HSP, UA-HSP and UEA-HSP) were systematically investigated. The yield of the polysaccharides (20.70±0.17%) obtained by ultrasonic-enzyme assistance was higher than the polysaccharides by other methods'. Four kinds of polysaccharides possessed the different preliminary structural characteristics including molecular weight distributions, monosaccharide compositions, crystallization and spiral structures, while different surface morphology. Through the measurements of antioxidant activities in vitro, UEA-HSP exhibited the most significant scavenging capacities on non-physiological ABTS free radicals and physiological hydroxyl radicals. These data showed that ultrasonic-enzyme assistance was more beneficial to enhance the extraction yields of the polysaccharides, and obtain higher bioactive polysaccharides. The results also suggested that H. serotina polysaccharides possessed potential healthcare application in food field due to their antioxidant activities.

Li X ，Wang L 《-》

Synthesis of selenium-containing polysaccharides and evaluation of antioxidant activity in vitro.

Selenium (Se) is an essential trace element for human beings and many other forms of life. Organic Se from natural foods has higher bioavailability and is safer than inorganic Se species. In the present study, selenium-containing derivatives of Artemisia sphaerocephala polysaccharide with the highest Se content of 1703 μg/g were synthesized using H(2)SeO(3)/HNO(3) and BaCl(2) as a catalyst. The effects of the ratio of HNO(3) concentration and reaction temperature were investigated. Results of Raman and (13)C NMR spectroscopy indicated that C-6 substitution was predominant in selenized polysaccharide. A sharp decrease in M(w) was observed in the selenized reaction due to the acid environment. The in vitro antioxidant results suggest that selenium-containing polysaccharide should be applied as a novel selenium source in dietary supplements, with potent antioxidant properties.

Wang J ，Zhao B ，Wang X ，Yao J ，Zhang J ... -  《-》

Preparation, physicochemical property and in vitro antioxidant activity of zinc-Hohenbuehelia serotina polysaccharides complex.

Zinc deficiency in human body gradually becomes a critical challenge to public health in modern society. Therefore, the purpose of the study was to prepare zinc-Hohenbuehelia serotina polysaccharides (HSP) complex, analyze the physicochemical properties and investigate in vitro antioxidant activity of zinc-HSP complex. The results of atomic absorption spectrometric (AAS) and energy dispersive spectrum (EDS) analyses confirmed that zinc was successfully bound to HSP. The prepared zinc-HSP complex was a semi-crystalline substance, with compact and smooth morphology and triple-helix spatial structure. It possessed well swelling property and low moisture content. Antioxidant results suggested zinc-HSP complex possessed the significant inhibitory effects against hydroxyl, ABTS and superoxide anion radicals in vitro as HSP did, which further indicated that conjunction of zinc did not change the biological activity of HSP. The present study provides a theoretical basis for application of organozinc complex in functional food field.

Wang L ，Li X 《-》

Characterization, antioxidant, antineoplastic and immune activities of selenium modified Sagittaria sagittifolia L. polysaccharides.

This study proposed an optimal way to supplement organic selenium, boost polysaccharides solubility, antioxidant, anticancer, immune responses. A purified polysaccharide fraction of Sagittaria sagittifolia L. (PSSP) was successfully modified with selenium (Se-PSSP), and its characteristics, antioxidant, antineoplastic and immune activities were studied. The structure and the monosaccharide composition were determined by means of UV-visible spectrometry, FT-IR spectra, NMR spectra, X-ray diffraction spectroscopy (XRD), scanning electron microscope (SEM) and atomic force microscope (AFM). The results showed that both PSSP and Se-PSSP contained a pyranoid polysaccharide linked by α-glycosidic bonds in the main chain. In addition, PSSP and Se-PSSP were amorphous morphology without three-helix conformation. PSSP (47.12 kDa) was mainly composed of glucose, mannose and xylose with molar percentages of 55.82%, 14.86% and 14.35%, respectively. Se-PSSP (16.82 kDa) is mainly composed of glucose, xylose and galactose with molar percentages of 26.49%, 18.76% and 18.14%, respectively. Compared with PSSP, Se-PSSP showed stronger water-solubility, antioxidant activity, cytotoxicity and immunomodulatory activity than that of PSSP. These results suggested that Se-PSSP is a promising novel Se-supplement and may be served as an excellent potential antioxidant, antineoplastic, and immunomodulatory agents in the field of functional foods and medicine industry.

Feng Y ，Qiu Y ，Duan Y ，He Y ，Xiang H ，Sun W ，Zhang H ，Ma H ... -  《-》