Chemical analysis of a new (1→3)-, (1→6)-branched glucan from an edible mushroom, Pleurotus florida

Structural elucidation of a biologically active heteroglycan isolated from a hybrid mushroom of Pleurotus florida and Lentinula edodes

A water soluble heteroglycan isolated from hot aqueous extract of fruit bodies of an edible hybrid mushroom Pfle1r of Pleurotus florida and Lentinula edodes consists of d-glucose, d-mannose, and d-galactose residues in a molar ratio of nearly 1:1:1. This polysaccharide showed macrophage, splenocyte, and thymocyte activation. On the basis of sugar hydrolysis, methylation, periodate oxidation study, and NMR studies (1H, 13C, DEPT-135, TOCSY, DQF-COSY, NOESY, ROESY, HSQC, and HMBC), the structure of the repeating unit of the polysaccharide was established as: -->6)-α-D-Galp-(1-->6)-α-D-Glcp-(1-->2<--1β-D-Manp.

Beta glucan: a valuable functional ingredient in foods

β-Glucan is a valuable functional ingredient and various extraction techniques are available for its extraction. Choice of an appropriate extraction technique is important as it may affect the quality, structure, rheological properties, molecular weight, and other functional properties of the extracted β-glucan. These properties lead to the use of β-glucan into various food systems and have important implications in human health. This review focuses on the extraction, synthesis, structure, molecular weight, and rheology of β-glucan. Furthermore, health implications and utilization of β-glucan in food products is also discussed.

Chemical characterization, antiproliferative and antiadhesive properties of polysaccharides extracted from Pleurotus pulmonarius mycelium and fruiting bodies

Mushroom polysaccharides are potent substances that exhibit antitumor and immunomodulatory properties. Studies comparing the chemical composition and antitumor-related activities of polysaccharides released by fungal strains under different growth conditions are not available. Thus, the present study compared polysaccharides extracts produced by Pleurotus pulmonarius from mycelium grown in liquid culture (ME) or fruiting bodies (FBE). Polysaccharides of both ME and FBE had a relatively high molecular mass. NMR spectroscopy indicated that ME glucan is an alpha-glucan whereas FBE glucan is a mixture of both alpha- and beta-glucans. Glucose and galactose where the most prominent monosaccharide in both glucans. Treatment of several colon cancer cell lines expressing varying amounts of galectin-3 with the two fungal glucans inhibited their viability and significantly reduced their ability to adhere to the key component of the extracellular matrix, fibronectin, and to a human umbilical vein endothelial cell monolayer, in a time- and dose-dependent manner mainly in those cell lines expressing high amounts of galectin-3. We conclude that ME and FBE glucans may exert a direct antiproliferative effect on cancer cells expressing high galectin-3 concentrations and concomitantly downregulate tumor cell adherence, the latter being directly related to cancer progression and metastasis.

Orally administered glucans from the edible mushroom Pleurotus pulmonarius reduce acute inflammation in dextran sulfate sodium-induced experimental colitis

Polysaccharides are one of the most potent mushroom-derived substances exhibiting anti-inflammatory and immunomodulatory properties. The aims of the present study were to determine whether orally administered glucans from the edible mushroom Pleurotus pulmonarius could attenuate or prevent the development of experimental colitis in mice. Colonic inflammation was induced in mice by treatment with 3.5 % dextran sulfate sodium (DSS) for 18 d. Before or after DSS administration, mice were given hot water solubles (HWS) or mycelium extract (ME) (2 or 20 mg per mouse) daily in their food. Colonic damage was macroscopically and histologically evaluated. Inflammation was assessed by changes in colon length, TNF-alpha levels released by colonic samples in organ culture and myeloperoxidase (MPO) activity. mRNA levels of pro-inflammatory (IL-1beta) and anti-inflammatory (IL-10) cytokines in colonic samples were determined by quantitative real-time RT-PCR. P. pulmonarius glucans attenuated and prevented the development of symptoms associated with DSS-induced colitis. High doses of HWS and ME blocked colon shortening, suppressed MPO activity and improved macroscopic score in all treatment groups. In addition, histological damage from colitis was reduced by HWS and ME at all doses. The tissue levels of TNF-alpha protein were significantly decreased and correlated with degree of inflammation and macroscopic score. All treatments significantly attenuated the increased DSS-mediated expression levels of IL-1beta. We conclude that the different glucan preparations (HWS or ME) harvested from P. pulmonarius when orally administered to DSS-treated mice attenuate the development of colonic inflammation, suggesting putative clinical utility for these extracts in the treatment of colitis.

Structural Characterization of Dietary Fiber of Green Chalcumra (Benincasa Hispida) Fruit by NMR Spectroscopic Analysis

A water-soluble dietary fiber was isolated from the hot aqueous extract of Chalcumra ( Benincasa hispida) fruit. The polysaccharide was found to contain D-galactose and D-methyl galacturonate in a molar ratio of 2:1. On the basis of acid hydrolysis, methylation analysis, periodate oxidation, and NMR spectroscopic studies (1H, 13C, TOCSY, DQF-COSY, NOESY, ROESY, HMQC, and HMBC), the repeating unit of the polysaccharide was established as →4)-β-D-Gal p-(1→4)-β-D-Gal p-(1→2)-α-D-Gal pA6Me-(1→.

Antimicrobial and antineoplasic activity of Pleurotus ostreatus

The objectives of this work were to evaluate the antimicrobial and antineoplasic activity of Pleurotus ostreatus DSM 1833. To study the antimicrobial activity, the following extracts were prepared: water infusion of the fresh fruiting bodies (B1), dehydrated fruiting bodies (B2), fresh mycelium (M1), and dehydrated mycelium (M2). Polysaccharides from the fresh mycelium were also obtained by water infusion followed by ethanol treatment (EP). The extracts were tested against Candida albicans, Escherichia coli, and Bacillus subtilis. To investigate the antineoplasic effect of P. ostreatus, the culture broth in natura, the extract from the culture broth (ECB), and the extract from the fruiting bodies were tested in female Swiss albino mice inoculated with the Ehrlich ascitic tumor (EAT). B1, B2, and M1 showed more than 50.0% inhibition against C. albicans. M2 presented a high degree of inhibition against E. coli (87.5%) and B. subtilis (57.5%), while EP was not effective. All the tested substances inhibited the development of EAT at levels near 70% when injected intraperitoneally in mice. The highest tumor inhibition (76%) was achieved for the treatment with ECB. The intragastric treatment did not promote any reduction in tumor cell development, independent of the test substance.