Velutipes Polysaccharides Research Articles

Bioactivity of the crude polysaccharides from fermented soybean curd residue by Flammulina velutipes

The solid-state fermentation, reusing soybean curd residue (SCR) as a solid substrate, was conducted for producing polysaccharides by Flammulina velutipes (F. velutipes). The optimal fermentation conditions were 74.5% of moisture content, 9.69 of inoculum size and 30.27 of C/N ratio by response surface methodology. 59.15mg/g of polysaccharides were obtained. F. velutipes polysaccharides were subsequently extracted from fermented SCR by ultrasonic assisted extraction. The optimal extract conditions were 30min, 80°C, 150W and 20 of water to solid ratio and 106.74mg/g of polysaccharides were obtained. Furthermore, the antioxidant and the immunomodulatory activities of polysaccharides were assessed. The results showed that polysaccharides exhibited a strong DPPH radical scavenging activity, SOD-like activity, stimulatory the proliferation of the macrophage, the production of nitric oxide, phagocytosis and the protection on Doxorubicin damage. These could lay the foundation for changing SCR into a nutritious functional food or a food additive.

Optimization of ultrasonic extraction of Flammulina velutipes polysaccharides and evaluation of its acetylcholinesterase inhibitory activity

Polysaccharide was testified to be the main component of Flammulina velutipes for inhibiting AChE activity in our preliminary study. Therefore, response surface methodology, based on Box–Behnken design, was used to optimize the ultrasonic extraction conditions of F. velutipes polysaccharides (FVP). Four independent variables (ratio of water to raw material, ultrasonic power, ultrasonic time, and ultrasonic temperature) were taken into consideration. A quadratic model, adequate for reasonably predicting the yield of FVP, was constructed between ultrasonic conditions and yield of FVP. A yield of FVP of 8.33% was obtained under a modified condition (ratio of water to material of 25ml/g, ultrasonic power of 620W, ultrasonic time of 20min, and ultrasonic temperature of 45°C). Subsequently, acetylcholinesterase (AChE) inhibitory activity and 1,1-diphenyl-2-picryl hydrazine (DPPH) scavenging activity of FVP were determined. AChE inhibitory rate of 18.51% and DPPH scavenging rate of 61.24% were obtained at 0.6mg/ml of FVP, indicating a good potential of FVP to enhance learning and cognitive ability.

Purification, Characterization and Immuno-Modulating Properties of Polysaccharides Isolated fromFlammulina velutipesMycelium

To investigate the immuno-modulating activity of Flammulina velutipes mycelium, three different Flammulina velutipes polysaccharides (FVPs) were isolated by fractionation using gel filtration and were identified as the immunomodulators of murine peritoneal macrophages. Based on the results of fourier transform infrared spectroscopy (FTIR), high performance liquid chromatography (HPLC), NMR spectroscopy, methylation analysis and gas chromatography-mass spectrogram (GC-MS), FVP2C was identified as glucose, galactose, mannose and fucose in molar ratio of 100: 14: 7: 4. FVP2C, molecular weight of 27.3 x 10(3) Da, was characterized as alpha-D-(1-->4)-glucan which was highly branched with alpha-D-(1-->6)-glucosyl residues, a single galactose or small amounts of mannoses and fucose at the C-6 position every twelve residues, on average, along the main chain. In the present study, it was found that three FVPs induced a significant increase in cellular nitric oxide formation, interleukin-1 production and tumor necrosis factor-alpha secretion in macrophages in vitro. The immuno-modulating activity of FVP2A, FVP2B and FVP2C was dose-dependent.