| Phellinus mori Y.C. Dai&B.K. Cui was described from northern China in2008. It belongs to the Phellinus laevigatus complex and inhabits on Morus exclusively. In addition, more extracellular polysaccharide was produced by liquid culture mycelia. Like other medicinal fungi in Phellinus, there is a great potential that Phellinus mori is considered as a new medicinal mushroom. However, no studies on its biological properties, metabolic substances, and pharmacological effects were done previously, Therefore, the culture conditions, structure and pharmacological activity of extracellular polysaccharide were studied.The solid culture conditions of Phellinus mori were studied. The results showed that starch gave the maximum growth rate with less biomass, and glucose and maltose did the opposite. Yeast extract powder was the optimum nitrogen source. The variation of pH value between5.5-8.0did not affect the mycelial growth significantly, and the optimum temperature for mycelial growth was from28℃to33℃. The optimal culture conditions were found for the production of mycelial biomass and exopolysaccharides (EPSs) in Phellinus mori by submerged culture. According to the orthogonal array design, the relative optimum medium compositions for biomass and EPSs production were maltose30g/L, yeast extract powder and peptone (2:1)15g/L, KH2PO4and CaCl2(1:1)5.5g/L, initial pH6. The single factor experiment showed that the optimal liquid medium volume was120mL/250mL and the optimal inoculum volume was10%. Variations of four extracellular enzymes from Phellinus mori in liquid culture were studied. The results showed that Phellinus mori had rich extracellular enzymes. The results also indicated Phellinus mori preferred starch to pectin, cellulose and lignin. In addition, the protein concentration had two peaks on day8and11, respectively. The reducing sugar concentration decreased gradually with the incubation time, and the pH value decreased on days2-7but increased after day8.The exopolysaccharides (PM-EPS1, PM-EPS3) produced by mycelia submerged culture of Phellinus mori were isolated by a gel-filtration chromatography and their chemical characterization were characterized by high performance anion exchange chromatography (HPAEC), gel permeation chromatography (GPC), fourier transform-infrared (FT-IR) spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. Subsequently, their biological activities, especially preliminary antioxidant activities in vitro, were evaluated. The results showed that both PM-EPS1and PM-EPS3were heteropolysaccharides consisting of mannose, glucose, galactose, and rhamnose and the weight-average molecular mass of PM-EPS1and PM-EPS3were4,990g/mol and27,890g/mol, respectively. FT-IR spectral analysis of PM-EPS1and PM-ESP3revealed prominent characteristic groups corresponding to carbohydrates.1H and13C NMR spectroscopy analysis indicated that PM-EPS3had a(1→4)-linked mannopyranosyl backbone, with branches of (1→4)-linked glucosyl residues and (1→3,4)-linked galactopyranosyl residues. Preliminary activity tests in vitro revealed that PM-EPS3had antioxidant activity.The in vitro antioxidant activities of the methanol extract (ME), chloroform extract (CE), ethyl acetate extract (EAE), butanol extract (BE) and hot water extract (WE) from Phellinus mori, Phellinus baumii and Phellinus vaninii were investigated. The results indicated that EAE had the highest1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity compared with the other fractional extracts. The hot water extracts (WE) all displayed higher hydroxyl radical (-OH) scavenging activity. Overall, the different extracts from Phellinus vaninii had the most capacity for antioxidant activities, then was Phellinus baumii, and Phellinus mori had the weakest capacity for antioxidant activities. |
PDF Full Text Request