Effect of Carbon Source on Properties and Bioactivities of Exopolysaccharide Produced by Trametes ochracea (Agaricomycetes).

The effects of carbon source on properties and bioactivities of exopolysaccharide (EPS) produced by Trametes ochracea were investigated in this study. The results indicated that EPS production varied with five different carbon sources. After a fermentation period of 8 days, sucrose was the most suitable carbon source for biomass and EPS production. The predominant carbohydrate compositions in EPSs identified were glucose and mannose. The EPS fermented by sucrose has the highest glucose content. Then, FT-IR spectral analysis revealed prominent characteristic groups in EPSs. Each particular EPS possessed the specific bands at 808-809 cm-1 and 914-922 cm-1, indicating both α- and ß-configurations of the sugar units. Furthermore, thermogravimetric analysis (TGA) indicated the EPS with sucrose and glucose as carbon source showed different degradation behavior compared with the other three EPSs. The variation also affects antioxidant and antihyperlipemia activities investigated using hydroxyl and DPPH radical scavenging assay, and in hyperlipemia mice. Sucrose was the best carbon source from the viewpoint of OH and DPPH radical scavenging activities, and antihyperlipemia activity, probably due to the relatively high glucose content in EPS.

Production, structural characterization, and antiproliferative activity of exopolysaccharide produced by Scleroderma areolatum Ehrenb with different carbon source.

The effects of different three carbon sources, that is, glucose, fructose, and sucrose, on production, molecular properties and antiproliferative activity of exopolysaccharide (EPS), were evaluated in the submerged culture of Scleroderma areolatum Ehrenb. Among carbon sources examined, the addition of sucrose maximizes the mycelia production, while fructose could maximize the EPS yield. Although the predominant carbohydrate compositions identified were gluconic acid and mannose, the monosaccharide composition of EPSs was also different significantly. FT-IR spectral analysis revealed there was no significant difference among the prominent characteristic groups in three EPSs. The molecular weight of EPSs was also affected by carbon source, being generally lower compared with that with glucose. However, all EPSs molecule existed as nearly globular shape form in aqueous solution. The variation of carbon sources also affected antiproliferative activity examined in vitro using cell proliferation assay. Fructose was optimal carbon source giving higher antiproliferative activity probably due to the relatively high contents of xylose in the EPS with low molecular weight.

Molecular Characterization of Two Polysaccharides from Phellinus vaninii Ljup and their Cytotoxicity to Cancer Cell Lines.

BACKGROUND: Phellinus vaninii, a medicinal basidiomycete fungus, is often confused with Phellinus igniarius and Phellinus linteus. Polysaccharides extract from P. igniarius and P. linteus are reported to stimulate humoral immunity and inhibit tumor growth However, available literature reviewed no information on the relationship between bioactivities and structures of polysaccharides from the fruit body of P. vaninii. METHODS: Two water-soluble polysaccharides (PV-W, PV-B) were isolated and purified from fruiting bodies of P. vaninii by hot water and sodium hydroxide solution, respectively. The chemical structures of PV-W, PV-B were analyzed by FT-IR, GC-MS analysis and 13C NMR spectra. And, their molecular conformations were analyzed by viscosity method and SEC-MALLS-RI. Finally, their inhibition of cancer cells was investigated using MTT assay. RESULTS: The results illustrated that PV-W was a heteropolysaccharide, mainly composed of mannose, glucose, arabinose and galactose. PV-B was a ß-1, 3-D-glucan branched with ß-1, 6-D-glucose. The results of viscometry proved that PV-W and PV-B could be molecularly dispersed in water without aggregation. The results of SECMALLS- RI indicated that the two polysaccharides had the similar Mw but different molecular conformation. That is, PV-W existed as a stable globular shape, while PV-B presented a more expanded flexible random coils conformation. MTT assay indicated that PV-B showed higher inhibition effect on HepG2 and HeLa cells than PV-W in vitro. CONCLUSION: This work provided the important information of active components from P. vaninii and its potential applications in the food and medicine industry.

Effect of carbon source on production, characterization and bioactivity of exopolysaccharide produced by Phellinus vaninii Ljup

ABSTRACT The effect on different three carbon source (i.e. glucose, fructose and sucrose) on production, chemical characterization and antioxidant activity of exopolysaccharide (EPS) produced by Phellinus vaninii Ljup was investigated in this study. Amongst carbon sources examined, glucose and sucrose were favorable for the mycelia growth, while the maximum EPS yield was achieved when sucrose was employed. The predominant carbohydrate compositions in EPSs identified were gluconic acid, glucose, mannose and galactose acid. Then, FT-IR spectral analysis revealed prominent characteristic groups in EPSs. EPSs molecule exist as nearly globular shape form in aqueous solution. The variation also affects antioxidant activities by investigated by using hydroxyl and DPPH radical scavenging assay. Sucrose was best carbon source from the viewpoint of antioxidant activity due to the relatively high contents of galactose in the EPS with moderate molecular weight and polydispersity.

Construction of selenium nanoparticles/ß-glucan composites for enhancement of the antitumor activity.

We report on a green procedure for the stabilization of selenium nanoparticles (SeNPs) by a naturally occurring ß-glucan with triple helical conformation known as Lentinan (t-LNT) in water after denaturing into single chains (s-LNT) at 140 °C. The results demonstrated that the s-LNT can interact with SeNPs through Se-O-H interaction. Transmission electron microscopy (TEM), energy dispersive X-ray (EDX) spectra, UV/vis, X-ray diffraction (XRD) and dynamic light scattering (DLS) showed that s-LNT coated SeNPs to form a stable nano-composite Se/s-LNT, leading to good dispersion of SeNPs. Especially, the as-prepared Se/s-LNT composite in the solution could remain homogeneous and translucent for 30 days without any precipitates. Different size distribution of SeNPs was prepared by simply controlling the concentrations of selenite sodium and the corresponding reducing agent ascorbic acid. The size effect of SeNPs on anti-tumor activity was revealed that the SeNPs with more evenly particle size distribution show the higher anticancer activity.

Optimization, Purification, Characterization, and Antioxidant Activity of Exopolysaccharide Produced by the Northern Tooth Mushroom, Climacodon septentrionalis (Basidiomycota).

The optimization, purification, and characterization of exopolysaccharide (EPS) from Climacodon septentrionalis were investigated. The results showed that the optimal incubation time was 8 days for EPS production by C. septentrionalis; maltose and soy extract were the best carbon and nitrogen sources, respectively. One kind of EPS fraction was purified; it had a molecular weight of about 3.4 × 10(5) Da and mainly comprised glucose (98%). The main structure of EPS is α-glucopyranose. In addition, the EPS showed good antioxidant properties in vitro. The thermal stability of EPS also was investigated, and the results suggest that to maintain its bioactivity the processing temperature of EPS should not be more than 200°C. The structural characteristics of EPS, such as molecular weight, functional groups, monosaccharide constituents, and configuration of the glycosidic bond give EPS great potential for application as a natural antioxidant material in health, food, and therapeutics.

Effects of calcium carbonate polymorph on the structure and properties of soy protein-based nanocomposites.

Novel protein-based nanocomposites were well prepared by in vivo synthesis and co-precipitation of soy protein isolate (SPI) with calcium carbonate (CaCO3) in an aqueous solution. The resultant CaCO3 in the nanocomposites was identified as calcite- and aragonite-type, respectively. The morphology and structure of the CaCO3/SPI composites were investigated by means of wide-angle X-ray diffraction, Fourier transform infrared spectra, scanning electron microscopy, and high-resolution transmission electron microscopy. The results revealed that the polymorph and the size of CaCO3 in the nanocomposites were dependent on its content, pH, and the conformation of soy protein. At the content of more than 5%, CaCO3 was changed into calcite crystal with the preference of growing along (104) plane. However, at lower content of less than 5%, CaCO3 preferred to form aragonite in the composite as a result of the modulation by soy protein. The aragonite nanocrystals were arrayed in the direction of (111) plane and self-assembled along beta-sheet planes of soy protein polypeptides. The mechanical properties, thermal stability, and water resistance of the CaCO3/SPI nanocomposites were significantly improved as a result of the nanosized effects. Interestingly, the aragonite/SPI nanocomposite exhibited higher tensile strength (about 50 MPa) than that of calcite/SPI, owing to a good compatibility and strong interaction between aragonite and soy protein polypeptides. This work provided a simple pathway to develop the soy protein-based bio-hybrid materials with high mechanical strength and valuable information on their structure-properties relationship.