High-Level Production of Exopolysaccharides by a Cosmic Radiation-Induced Mutant M270 of the Maitake Medicinal Mushroom, Grifola frondosa (Agaricomycetes).

A new Grifola frondosa mutant, M270, was successfully isolated for high production of exopolysaccharides (EPSs) using cosmic radiation-induced mutagenesis. We found that the mutant M270 had a clearer and thicker EPS layer (~10 µm) adhering to mycelia than those of its parent strain 265 after Congo red staining. In the 20-L batch fermentation for M270, 10.3 g/L of EPS and 17.9 g/L of dry mycelia biomass were obtained after 204 hours of fermentation. Furthermore, a main water-soluble fraction (EP1) in the EPS was purified from M270 and then confirmed to be heteroglycan-protein complex with 91% (w/w) total carbohydrates and 9% (w/w) total proteins. Four kinds of monosaccharide-D-mannose, D-glucosamine, D-glucose, and D-xylose-were detected in EP1 with a molar ratio of 17.6:1.8:100:2.5. The molecular mass of the main component in EP1 was 8.9 kDa. The EPS from M270 significantly inhibited the growth of sarcoma 180 solid tumors in mice. This G. frondosa M270 mutant could serve as a better candidate strain for polysaccharide production.

Optimization of Liquid Fermentation Medium for Production of Inonotus sanghuang (Higher Basidiomycetes) Mycelia and Evaluation of their Mycochemical Contents and Antioxidant Activities.

Inonotus sanghuang, an authentic "Sanghuang" mushroom used in traditional Chinese medicine, is known to possess important pharmacological activities. In this study, we aimed to optimize the liquid fermentation medium for I. sanghuang mycelial production and to determine the effects of two-stage cultivation (shake and static) on the yield of total flavonoids, total phenolics, and polysaccharides, as well as the antioxidant activities of I. sanghuang mycelial extracts (ISME). Under an optimized medium composition (38.96 g/L of corn flour, 4.15 g/L of yeast extract, 20.55 g/L of bran and pH 6.39), the predicted and experimental optimal mycelial biomasses were 17.60 g/L and 18.33±0.86 g/L, respectively. The results of two-stage cultivation showed that contents of total flavonoids and total phenolics in mycelia increased by 37.92% and 77.27%, respectively. However, irregular polysaccharide contents were noted throughout the experimental period. Antioxidant assays showed that ISME possessed good free-radical scavenging activity, which is mainly contributed by polyphenolic-type metabolites.

Immunomodulatory effect of polysaccharides extracted from the medicinal mushroom Antrodia camphorata (higher Basidiomycetes) in specific pathogen-free chickens.

The immunomodulatory effect of polysaccharides extracted from mycelia of the medicinal mushroom Antrodia camphorata in submerged culture was studied in 100 specific pathogen-free (SPF) chickens. The chickens were randomly divided into 2 groups (50 per group). For the treated group, each kilogram of SPF chickens was fed 5 mg of A. camphorata extract (ACE) for 35 consecutive days. Chickens were killed on days 7, 14, 21, 28, and 35, and lymphocytes were separated from the blood, spleen, thymus, bursa, kidney, and pancreas of the chickens. The results showed that, compared to the control group, the immune organ indices (except for the thymus) were higher after 14 days (P < 0.05), and the contents of globulin in blood were significantly increased on the 21st day (P < 0.05). The most of biochemical indices did not significantly changed within 35 days of treatment. Moreover, the response of proliferation and the rates of positive T lymphocytes in blood were higher than in the control group (P < 0.05).The results presented herein indicate that ACE could enhance the immune functions of the organs in SPF chickens and could be an attractive application of nutraceuticals and pharmaceuticals.

Discovery of a new sesquiterpenoid from Phellinus ignarius with antiviral activity against influenza virus.

Seven natural products, including one new sesquiterpenoid (eudesm-1ß, 6α, 11-triol, compound 1), one ergosta -4, 6, 8(14), 22-tetraen-3-one (compound 2), four polyphenols (compounds 3, 4, 5, 6), and one pyrone (3-hydroxy-2-methyl-4-pyrone, compound 7) were isolated from cultures of Phellinus ignarius by column chromatography. The detailed structure of compound 1 was determined using a combination of one- and two-dimensional nuclear magnetic resonance, mass spectrometry and infrared spectroscopy. The antiviral activity of these compounds against H5N1 influenza A virus was investigated using an MTT colorimetric assay system in Madin-Darby canine kidney cells. The results indicate that compound 1 possesses significant ability to inhibit influenza virus. The 50 % effective concentration was 0.14 ± 0.04 µM. Molecular modeling further suggested that the anti-influenza virus activity of this compound was partially attributed to the interactions of hydroxyl groups with an amino acid residue (Asn 170) of neuraminidase (NA) at the binding site. Moreover, the results of enzyme inhibition assays indicated that 50 % inhibition of NA was achieved by compound 1 at a concentration of 0.657 ± 0.325 mg/mL, which suggested that compound 1 is likely to interact with the NA enzyme.