Soumitra Paloi

Structure elucidation and antioxidant properties of a soluble β-d-glucan from mushroom Entoloma lividoalbum

A water soluble branched β-D-glucan (PS-I) with an average molecular weight ~2.1×10(5) Da was isolated from alkaline extract of the fruit bodies of the edible mushroom Entoloma lividoalbum (Kühner & Romagn) Kubička which consists of terminal β-D-glucopyranosyl, (1→3)-β-D-glucopyranosyl, (1→6)-β-D-glucopyranosyl, and (1→3,6)-β-D-glucopyranosyl moieties in a molar ratio of nearly 1:3:2:1. The structure of PS-I was elucidated using acid hydrolysis, methylation analysis, periodate oxidation study, partial hydrolysis, and 1D/2D NMR experiments. The repeating unit of the polysaccharide (PS-I) contains a backbone chain of three (1→6)-β-D-glucopyranosyl residues, one of which was branched at O-3 position with the side chain consisting of three (1→3)-β-D-glucopyranosyl and a terminal β-D-glucopyranosyl residues. Total antioxidant capacity of 1mg PS-I was measured and found equivalent to 70±15 μg of ascorbic acid. The PS-I was found to possess hydroxyl and superoxide radical-scavenging activities with EC50 values of 480 and 150 μg/mL, respectively. The reducing power of PS-I was determined 0.5 at 480 μg/mL.

Selective inhibition of Leishmania donovani by active extracts of wild mushrooms used by the tribal population of India: An in vitro exploration for new leads against parasitic protozoans

The study was intended at evaluating the anti-proliferating effect of mushrooms used in traditional folklore of Santal tribal population in India against Leishmania donovani (MHOM/IN/83/AG83). A total of eighteen extracts, three estracts from each mushroom [(80% ethanol extracted; Fa), (water-soluble polysaccharide fraction; Fb), (polyphenolic fraction; Fc)], from six wild mushrooms were obtained. These extracts were tested against the promastigotes and amastigotes for their antileishmanial capacity. Fa fractions (250 μg/mL) of Astraeus hygrometricus and Tricholoma giganteum significantly inhibited the growth of L. donovani promastigotes and interfered in lipid biosynthesis. Moreover, both fractions induced apoptosis in promastigotes. Water soluble Fb fractions of A. hygrometricus, Russula laurocerasi, Russula albonigra, Termitomyces eurhizus, Russula delica and polyphenolic Fc fraction of R. laurocerasi were found to inhibit the replication of intracellular amastigotes in macrophages dose dependently. Significantly, 50% inhibitory concentration of the active extracts against intracellular amastigotes induced release of nitric oxide and IL-12 in murine macrophages and dendritic cells assay and also found considerably non-toxic on murine splenocytes. Results of this study can be used as a basis for further phytochemical and pharmacological investigations in the effort for search of novel anti-leishmanial leads.

Structural, immunological, and antioxidant studies of β-glucan from edible mushroom Entoloma lividoalbum

A water soluble β-glucan having molecular weight ∼2×10(5)Da was isolated from hot water extract of the fruit bodies of an edible mushroom Entoloma lividoalbum (Kühner & Romagn) Kubička. This polysaccharide (ELPS) contains (1→3,6)-β-D-Glcp, (1→3)-β-D-Glcp, (1→6)-β-D-Glcp, and terminal β-D-Glcp moieties in a molar ratio of nearly 1:1:3:1. Chemical and spectroscopic analysis showed that the backbone of glucan consists of three (1→6)-β-D-glucopyranosyl and two (1→3)-β-D-glucopyranosyl residues, out of which one (1→3)-β-D-glucopyranosyl moiety was branched at O-6 with a terminal β-D-glucopyranosyl residue. This β-glucan exhibited macrophage, splenocyte, and thymocyte stimulations. It possesses promising antioxidant activities as evidenced from its hydroxyl and superoxide radical scavenging activities and reducing properties.

Structural characterization and antioxidant activity of a glucan from Meripilus giganteus

A new water soluble glucan (MGPS), with a molecular weight ∼1.48×105Da, was isolated from the fruit bodies of Meripilus giganteus by hot water extraction followed by purification through dialysis tubing cellulose membrane and sepharose 6B column chromatography. Its structural characteristics were investigated by acid hydrolysis, methylation analysis, Smith degradation and 1D/2D NMR experiments. The monosaccharide composition analysis showed that MGPS contain only glucose. The backbone of MGPS was composed of two (1→3)-β-d-glucopyranosyl, two (1→6)-β-d-glucopyranosyl, two (1→6)-α-d-glucopyranosyl, and one (1→4)-α-d-glucopyranosyl residues, out of which one (1→3)-β-d-glucopyranosyl residue was branched at O-6 position with terminal α-d-glucopyranosyl residue and one (1→4)-α-d-glucopyranosyl residue branched at O-6 position with terminal β-d-glucopyranosyl residue. In vitro antioxidant studies showed that the MGPS exhibited hydroxide radical scavenging activity (IC50=390μg/mL), superoxide radical scavenging activity (IC50=70μg/mL), and ferrous ion chelating activity (IC50=290μg/mL).

Contribution to the Macromycetes of West Bengal, India: 8–12

Five members of Agaricales (Agrocybe pediades, Calocybella swetha, Cantharocybe virosa, Lepiota echinacea, and Oudemansiella canarii) were collected from different parts of West Bengal, India and are reported herein with detailed morphological characters. Literature survey revealed that all of the collected taxa represent their first distributional record from the state.

Introducing a novel mushroom from mycophagy community with emphasis on biomedical potency

Mushrooms have been prized by humankind as medicine and culinary wonder since antiquity. Though several species are ethnically valued; many prospective species are still being discovered. One such wild macrofungus has recently been discovered during subsequent field surveys in West Bengal, India which in turn exposed as a traditionally consumed popular myco-food. The collected taxon was found to be unique with regard to its morphological as well as genetical features. After detailed characterizations, the fungus was identified as a novel taxon belonging to the genus Russula (Russulaceae, Basidiomycota). Besides, the investigation was further extended in search of new functional ingredients and in this context, a water soluble crude polysaccharide rich extract (Rusalan) was isolated from dried basidiocarps. Accumulating evidences from GC-MS, HPTLC, FT-IR along with several spectrophotometric methods postulated that the fraction consisted mainly of carbohydrate in triple helical conformation, where glucose was the major monosaccharide mostly with β-type glycosidic linkage. Conversely, Rusalan showed pronounced antioxidant activity in six in vitro assay systems with EC50 value ranging from 190–1328 μg/ml concentration. The crude polysaccharide was also evaluated against six bacterial strains using microdilution method and the growth of Staphylococcus aureus and Bacillus subtilis were found to be inhibited effectively. In addition, immune-stimulatory assays demonstrated that Rusalan could evidently promote proliferation, induce phagocytosis, release NO, produce intracellular ROS and upregulate mRNA expression of iNOS, TNF-α, COX-2, as well as IL-6 genes in in mouse macrophage cells. Therefore, aim of the present study was not only to describe a new taxon to the world mycoflora but also to introduce a potent therapeutic agent that could be explored for food and pharmaceutical purposes. However, isolation of active component and in vivo studies need to be designed further.

Contribution to the Macromycetes of West Bengal, India: 23–27

For Focus, Scope, Aims, Policies and Guidelines visit http://threatenedtaxa.org/index.php/JoTT/about/editorialPolicies#custom-0 For Article Submission Guidelines visit http://threatenedtaxa.org/index.php/JoTT/about/submissions#onlineSubmissions For Policies against Scientific Misconduct visit http://threatenedtaxa.org/index.php/JoTT/about/editorialPolicies#custom-2 For reprints contact <info@threatenedtaxa.org> Short Communication Contribution to the Macromycetes of West Bengal, India: 23–27

Selective in vitro inhibition of Leishmania donovani by a semi-purified fraction of wild mushroom Grifola frondosa

The current study was designed to assess the anti-leishmanial effect of a semi-purified fraction of wild mushroom Grifola frondosa against Leishmania donovani, in vitro. A total of five extracts from three wild mushrooms [Grifola frondosa (family, Meripilaceae) Laetiporus sulphurous (family, Polyporaceae) and Meripilus giganteus (family, Meripilaceae) were explored for novel anti-leishmanial leads against promastigotes. The ethanol extract of G. frondosa was selected as the most efficient against L. donovani promastigotes (IC50: 93.9 μg/mL). A semi-purified fraction was obtained from an active ethanol extract of G. frondosa and found to inhibit the survival of promastigotes of L. donovani (MHOM/IN/83/AG83) significantly (IC50: 20.37 μg/mL) and it also had some effect against L. major LV39 (MRHO/Sv/59/P strain) and L. tropica WR683 (MHOM/SU/58/OD) strains at higher concentrations (IC50: 46.08 μg/mL and 53.79 μg/mL respectively). The semi-purified fraction also interfered in lipid biosynthesis, altered parasite morphology and induced apoptosis in L. donovani promastigotes. The semi-purified fraction was also effective against intracellular amastigotes in infected macrophages and enhanced the release of nitric oxide and pro-inflammatory cytokines, in vitro. Interestingly, the 50% inhibitory concentration of the semi-purified fraction against the intracellular amastigotes (IC50: 2.48 μg/mL) was much lower in comparison to promastigotes (IC50: 20.37 μg/mL). The semi-purified fraction was found to inhibit the intracellular amastigotes slightly more efficiently in comparison to conventional anti-leishmanial drugs; sodium antimony gluconate, amphotericin B, miltefosine and paromomycin and noticeably non-toxic towards host splenocytes. The findings of the present study established that G. frondosa might be a natural resource for development of a new anti-leishmanial lead.

Gymnopilus purpureosquamulosus Høil. (Agaricales, Basidiomycota): a new distributional record from India

Gymnopilus purpureosquamulosus Hoil ( Strophariaceae ) is reported for first time from India. A comprehensive description, a photograph, and comparisons with morphologically similar and phylogenetically related species are provided.