Optimization, characterization, rheological study and immune activities of polysaccharide from Sagittaria sagittifolia L

Physicochemical Characterization of an Exopolysaccharide Produced by Lipomyces sp. and Investigation of Rheological and Interfacial Behavior

The present study aimed to evaluate the rheological and interfacial behaviors of a novel microbial exopolysaccharide fermented by L. starkeyi (LSEP). The structure of LSEP was measured by LC-MS, ¹H and ¹³C NMR spectra, and FT-IR. Results showed that the monosaccharide composition of LSEP was D-mannose (8.53%), D-glucose (79.25%), D-galactose (7.15%), and L-arabinose (5.07%); there existed the anomeric proton of α-configuration and the anomeric carbon of α- and β-configuration; there appeared the characteristic absorption peak of the phosphate ester bond. The molecular weight of LSEP was 401.8 kDa. The water holding capacity (WHC, 2.10 g/g) and oil holding capacity (OHC, 12.89 g/g) were also evaluated. The results of rheological properties showed that the aqueous solution of LSEP was a non-Newtonian fluid, exhibiting the shear-thinning characteristics. The adsorption of LSEP can reduce the interfacial tension (11.64 mN/m) well and form an elastic interface layer at the MCT–water interface. Such functional properties make LSEP a good candidate for use as thickener, gelling agent, and emulsifier to form long-term emulsions for food, pharmaceutical, and cosmetic products.

A neutral polysaccharide with a triple helix structure from ginger: Characterization and immunomodulatory activity

A neutral ginger polysaccharide fraction (NGP) was isolated from ginger, and its primary structures and immunomodulatory activity were investigated. The results showed that NGP had a low molecular weight of 6305 Da. NGP principally consisted of glucose (93.88%) together with minor levels of galactose (3.27%) and arabinose (1.67%). Besides, results of methylation analysis and 1D/2D NMR spectroscopy demonstrated that NGP was α-glucan which had the main chain of 1,4-linked α-d-Glcp and α-d-Glcp residues branched at C-6 position which was different from the common triple helical β-glucans. NGP also displayed a remarkable immunological activity on the RAW264.7 cells in vitro. It could significantly enhance the proliferation of macrophages without cytotoxicity and increase the production of immune substances (NO, TNF-α, IL-1β and IL-6). The secretion at the concentration of 200 μg/mL was 29.41 μM, 1496.71, 44.30 and 1889.83 pg/mL for each substance, respectively. The results indicated that NGP could be a potential immune agent and might provide meaningful information for further chain conformation and immune mechanism research.

Characterization of a polysaccharide from the medicinal lichen, Usnea longissima, and its immunostimulating effect in vivo

A polysaccharide, CSL-0.1, was isolated from the medicinal lichen, Usnea longissima. CSL-0.1 was a neutral rhamnose-containing glucogalactomannan with a molecular weight of 7.86 × 104 Da. The polysaccharide had a core mannan structure with (1 → 6)-α-d-Manp units as the main chain and was substituted at the O-2 positions with side chains containing (1 → 2)-α-d-Manp residue, [3)-α-Glcp(1 → 4)-α-Glcp(1→] and 6-O-substituted β-d-Galf units. 2-O- and 2,3-di-O-substituted Rhap units. The effects of CSL-0.1 on intestinal immunity and antioxidant activity were evaluated. CSL-0.1 increased the spleen and thymus indices in a dose-dependent manner and conferred immunomodulation on reversing the Th1/Th2-related cytokine imbalance in cyclophosphamide (CP)-induced immunosuppressed mice. CSL-0.1 could also enhance the levels of secretory immunoglobulin A in CP-injected mice. Additionally, the antioxidant levels in the liver and intestine of the mice were increased 20%-50% after intragastric injection by CSL-0.1.

ARTP Mutagenesis to Improve Mycelial Polysaccharide Production of Grifola frondosa Using a Mixture of Wheat Bran and Rice Bran as Substrate

Mycelial polysaccharides from Grifola frondosa have shown potential for the prevention of chronic diseases. Atmospheric and room temperature plasma (ARTP) technology was used to enhance the ability of G. frondosa to efficiently utilize a mixture of rice bran and wheat bran in the production of mycelial polysaccharides. The ARTP-mutant G. frondosa GFA2 had an improved growth rate of 6.0 mm/d and polysaccharide yield of 2.65 g/L and showed stable genetic characteristics. Uniform design experiments showed that polysaccharide yield could be increased to 5.90 g/L using the optimized conditions of 10.0 g/L rice bran and 110.0 g/L wheat bran while omitting KH2PO4 and MgSO4·7H2O. Gas chromatography demonstrated that GFA2 polysaccharides were composed of the monosaccharides rhamnose, arabinose, fucose, xylose, mannose, glucose, and galactose. This study provides an effective strategy for improving polysaccharide production in edible fungi while proposing the added-value utilization of rice and wheat brans.

A polysaccharide of PFP-1 from Pleurotus geesteranus attenuates alcoholic liver diseases via Nrf2 and NF-κB signaling pathways

A polysaccharide named PFP-1 was isolated from the Pleurotus geesteranus fruiting body, and potential investigations on ameliorating oxidative stress and liver injury against alcoholic liver disease (ALD) were performed in mice. The animal studies demonstrated that PFP-1 had hepatoprotective effects by improving hepatocellular histopathology, modulating alcohol metabolisms and restoring the serum lipid levels. Besides, PFP-1 could attenuate oxidative stress and inflammatory responses by activating the Nrf2-mediated signal pathways and regulating the TLR4-mediated NF-κB signal pathways. The characterization indicated that PFP-1 was a typical pyranose-polysaccharide in a triple-helical conformation, which was linked by t-β-Glcp, 1,6-α-Glcp and 1,2,6-α-Galp. And the characteristic properties of higher water solubility and appropriate molecular weights contributed to the superior bioactivities. The results demonstrated that PFP-1 could be used as a supplement for alleviating alcohol-induced liver damage.