Structural characterization of a heteroglycan from an edible mushroom Termitomyces heimii.

A water soluble heteroglycan (THPS) of an average molecular weight ~1.98 × 105 Da was isolated from the aqueous extract of the fruit bodies of an edible mushroom Termitomyces heimii. Structural characterization of THPS was carried out using acid hydrolysis, methylation analysis, periodate oxidation, Smith degradation and 1D/2D NMR studies. Sugar analysis indicated the presence of glucose, mannose, galactose, and fucose in a molar ratio of nearly 6:2:2:1. The repeating unit of the THPS had a backbone consisting of four (1 â†’ 3)-ß-d-glucopyranosyl, one (1 â†’ 6)-ß-d-glucopyranosyl, two (1 â†’ 3)-α-D-manopyranosyl, and two (1 â†’ 6)-α-D-galactopyranosyl residues, out of which one (1 â†’ 3)-ß-d-glucopyranosyl residue was branched at O-6 position with terminal ß-d-glucopyranosyl residue and one (1 â†’ 6)-α-D-galactopyranosyl residue was branched at O-2 position with terminal α-L-fucopyranosyl residue.

Studies on structure and antioxidant properties of a heteroglycan isolated from wild edible mushroom Lentinus sajor-caju.

A water-soluble heteroglycan (PS-I) isolated from the aqueous extract of a wild edible mushroom Lentinus sajor-caju showed average molecular weight ∼1.79×105Da. The structure of the polysaccharide was determined using chemical and 1D/2D NMR experiments. Acid hydrolysis indicated the presence of d-glucose, d-galactose, d-mannose, and l-fucose in a molar ratio of nearly 4:4:1:1 respectively. The presence of terminal Fucp, terminal Galp, (1→3)-Glcp, (1→6)-Galp, (1→6)-Glcp, (1→4,6)-Galp, and (1→2,4)-Manp moieties were established from methylation analysis. The chemical and NMR analyses indicated that the PS-I was a heteroglycan composed of a repeating unit with backbone chain of three (1→6)-α-d-galactopyranosyl residues, two (1→6)-ß-d-glucopyranosyl residues, one (1→4)-α-d-mannopyranosyl residue, and two (1→3)-ß-d-glucopyranosyl residues where one (1→6)-α-d-galactopyranosyl residue was branched at O-4 position with terminal α-l-fucopyranosyl residue and (1→4)-α-d-mannopyranosyl residue was branched at O-2 position with terminal α-d-galactopyranosyl residue and the structure was proposed as; The PS-I is a moderate antioxidant compound which showed DPPH radical scavenging activity, hydroxyl radical scavenging activity, ABTS radical scavenging property, reducing power, and ferrous ion chelating ability.

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)-ß-d-glucopyranosyl, two (1→6)-ß-d-glucopyranosyl, two (1→6)-α-d-glucopyranosyl, and one (1→4)-α-d-glucopyranosyl residues, out of which one (1→3)-ß-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 ß-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).

Structural elucidation and immunostimulating property of a novel polysaccharide extracted from an edible mushroom Lentinus fusipes.

A water soluble heteroglycan (PS-II) with an average molecular weight∼60kDa was isolated from the hot aqueous extract of an edible mushroom Lentinus fusipes. The structural characterization of PS-II was carried out using total acid hydrolysis, methylation analyses, periodate oxidation, Smith degradation and 1D/2D NMR experiments. Total acid hydrolysis indicated the presence of D-galactose and D-glucose in a molar ratio of approximately 1:1. The chemical and NMR analyses revealed that the proposed repeating unit of the PS-II had a backbone chain consisting of three (1→6)-linked α-d-galactopyranosyl residue and two (1→6)-linked ß-d-glucopyranosyl residues, one of the ß-d-glucopyranosyl residue was branched at O-3 position with a terminal ß-d-glucopyranosyl. The PS-II exhibited significant in vitro splenocyte and macrophage activations with optimum dose of 20µg/ml and 80µg/ml respectively. Flow cytometry study revealed the protective role of the PS-II against nicotine stimulated lymphocytes. Moreover, the ROS scavenging property of PS-II was also established using DPPH radical scavenging assay.

Polysaccharide of an edible truffle Tuber rufum: Structural studies and effects on human lymphocytes.

A water-soluble heteroglycan (PS-II) with average molecular weight ∼7.27×104Da, was isolated from the fruiting bodies of an edible truffle mushroom Tuber rufum (Pico) var. by hot water extraction. The structural investigation of PS-II has been carried out using acid hydrolysis, methylation analysis, periodate oxidation, and 1D/2D NMR experiments. It was composed of d-glucose, d-galactose, l-fucose in a molar ratio of nearly 4:3:1 respectively. On the basis of these experiments, the repeating unit of the PS-II was found to contain a backbone of two (1→6)-α-d-galactopyranosyl, one (1→4)-α-d-glucopyranosyl, two (1→6)-ß-d-glucopyranosyl, and one (1→4)-ß-d-glucopyranosyl residues, out of which (1→4)-α-d-glucopyranosyl residue was branched at O-2 position with terminal α-l-fucopyranosyl residue and at O-6 position with terminal α-d-galactopyranosyl residue. Ameliorative activities of the PS-II was observed at different concentrations (25, 50, 100, 200, 400µg/ml) and it maintained the redox balance as well as reduced the lipid peroxidation to protect the cell damage.

Heteroglycan of an edible mushroom Pleurotus cystidiosus: Structural characterization and study of biological activities.

A water soluble heteroglycan (PCPS) was isolated from the aqueous extract of an edible mushroom Pleurotus cystidiosus. Structural characterization of the heteroglycan was carried out using total hydrolysis, methylation analysis, periodate oxidation, Smith degradation, and 1D/2D NMR experiments. Sugar analysis indicated the presence of glucose, galactose, and mannose in a molar ratio of nearly 6:2:1 respectively. The chemical and NMR analysis of the PCPS indicated the presence of a repeating unit with a backbone consisting of one unit of (1→6)-ß-d-glucopyranosyl, two (1→3)-ß-d-glucopyranosyl, one (1→3)-α-d-glucopyranosyl, one (1→6)-α-d-glucopyranosyl, and two (1→6)-α-d-galactopyranosyl moieties respectively, out of which one (1→3)-ß-d-glucopyranosyl residue was branched at O-6 with terminal ß-d-glucopyranosyl and another (1→6)-α-d-galactopyranosyl residue was branched at O-2 with terminal ß-d-mannopyranosyl moiety. The polysaccharide was found to exhibit cellular activities at different concentrations (10, 25, 50, 100, 200, 400µg/mL) and maintained the redox balance as well as reduced lipid per oxidation which protect the cell destruction.

A water soluble ß-glucan of an edible mushroom Termitomyces heimii: Structural and biological investigation.

A water soluble ß-glucan (PS-I) with an average molecular weight ∼ 1.48 × 10(5)Da was isolated from the alkaline extract of an edible mushroom Termitomyces heimii. PS-I contained (1 → 3)-, (1 → 6)-, (1 → 3, 6)-linked and terminal ß-d-glucopyranosyl moieties in a ratio of nearly 2:1:1:1. Based on the total hydrolysis, methylation analysis, periodate oxidation, Smith degradation, partial hydrolysis and 1D/2D NMR experiments the structure of the PS-I was elucidated. On the basis of these experiments, the repeating unit of the polysaccharide was found to consist of a backbone chain of two (1 → 6)-ß-D-glucopyranosyl residues, one of which was branched at O-3 position with the side chain consisting of two (1 → 3)-ß-D-glucopyranosyl and a terminal ß-D-glucopyranosyl residue. Cytotoxic effect of PS-I on human blood lymphocytes at varied concentrations was studied. Moreover, it also exhibited potent antioxidant activities by diminishing the ROS and NO in the nicotine stimulated lymphocytes up to 200 µg/ml.

Antibacterial and DNA degradation potential of silver nanoparticles synthesized via green route.

Silver nanoparticles (AgNPs) were synthesized using a hetero polysaccharide (PS) isolated from Lentinus squarrosulus (Mont.) Singer. The polysaccharide fraction (consisting of glucose, fucose and galactose) serves the role of both reducing as well as stabilizing agent. UV-vis spectroscopy showed maximum absorbance at 407 nm due to surface plasmon resonance. High resolution transmission electron microscopy (HRTEM) exhibited that the average diameter of the nanoparticles was 2.78±1.47 nm. The XRD analysis revealed face-centered cubic (fcc) geometry of silver nanoparticles. Antibacterial activity of the AgNPs-PS conjugate was tested against multiple antibiotics resistant (MAR) Escherichia coli strain MREC33 and found that the killing was due to generation of reactive oxygen species (ROS). Internalization of AgNPs-PS conjugate along with its DNA degradation capability was demonstrated using flow cytometry. AgNPs-PS conjugates showed negligible toxicity to human RBCs. This LD50 dosage of AgNPs-PS conjugates in combination with each of the four antibiotics (ampicillin, azithromycin, kanamycin and netilmicin) to which E. coli MREC33 was resistant, showed synergistic effect to inhibit complete bacterial growth.

Heteroglycan of an edible mushroom Termitomyces clypeatus: structure elucidation and antioxidant properties.

A water-soluble heteroglycan (PS) of an average molecular weight ∼1.98 ×10(5) Da was isolated from the aqueous extract of an edible mushroom Termitomyces clypeatus (R. Heim). The structure of the polysaccharide (PS) was established using total hydrolysis, methylation analysis, Smith degradation, and 1D/2D NMR experiments. Total hydrolysis indicated the presence of d-glucose, d-galactose, d-mannose, and l-fucose in a molar ratio of 4.10:1.95:1.0:0.95, respectively. The chemical and NMR analysis indicated the presence of a repeating unit with a backbone consisting of one each of the residues (1→3)-α-d-galactopyranosyl, (1→3)-α-d-mannopyranosyl, (1→3)-α-d-glucopyranosyl, (1→3)-ß-d-glucopyranosyl, (1→6)-ß-d-glucopyranosyl, and (1→6)-α-d-galactopyranosyl, respectively. The (1→3)-α-d-mannopyranosyl residue was found branched at O-2 with terminal α-l-fucopyranosyl moiety and (1→3)-ß-d-glucopyranosyl residue was branched at O-6 with terminal α-d-glucopyranosyl residue. The PS exhibited antioxidant properties.