Glucan of a somatic hybrid mushroom, pfls1h: structural characterization and study of immunological activities

Gastroprotective activity of polysaccharide from the fruiting body of Hericium erinaceus against acetic acid-induced gastric ulcer in rats and structure of one bioactive fraction

This study aimed at investigating gastroprotective activity of Hericium erinaceus polysaccharide (HEP) and characterizing one of its bioactive fractions. Acetic acid-induced gastric ulcer (GU) rat model was used to evaluate the gastroprotective activity of HEP, while H₂O₂-induced injury GES-1 cell model was conducted to screen the bioactive fractions from HEP. Moreover, one of the bioactive fractions was characterized using methylation and 1D/2D NMR analysis. Results indicated HEP treatment could ameliorate acetic acid-induced GU in rats. HEP supplement decreased levels of interleukin-6, tumor necrosis factor-α and malondialdehyde and myeloperoxidase activity, and increased releases of nitric oxide, prostaglandin E2, epidermal growth factor, vascular endothelial growth factor and basic fibroblast growth factor and superoxide dismutase activity in gastric tissues of ulcerated rats. Five purified polysaccharides from HEP were screened to be bioactive fractions with cytoprotection on H₂O₂-induced injury in GES-1 cells. Among them, RP-S was characterized to be a (1 → 6)-β-D-glucan, whose backbone was composed of →6)-β-D-Glcp-(1 → residue and branched with T-β-D-Glcp-(1 → residue at O-3 position. In conclusion, HEP possessed gastroprotection against acetic acid-induced GU in rats and one of its bioactive fractions was a β-D-glucan. This study supports the utilization of HEP in anti-GU and provides evidences for the structure of gastroprotective HEP.

Interspecific hybridization between Ganoderma lingzhi and G. applanatum through protoplast fusion

Interspecific hybridization between Ganoderma lingzhi and G. applanatum was attempted through polyethylene glycol (PEG) induced fusion technique. The protoplast isolation procedure was simplified, and we obtained a significant number of protoplasts from both Ganoderma species. The number of protoplasts obtained was 5.27 ± 0.31 × 10⁷/mL in G. lingzhi and 5.57 ± 0.49 × 10⁶/mL in G. applanatum. Osmotic stabilizer NaCl (0.4 M) at pH 5.8 and enzymolysis time 3.5 h have supported high frequency of protoplast regeneration. G. lingzhi and G. applanatum regeneration frequency was 1.73 ± 0.04% and 0.23 ± 0.02%, respectively. 40% of PEG induced high number of protoplast fusion the regeneration frequency was 0.09% on a minimal medium. Two hundred fifty-two fusant colonies were isolated from the following four individual experiments. Among them, ten fusants showed the mycelial morphological difference compared to their parents and other fusant isolates. The fruiting body could be generated on oak sawdust and wheat bran substrate, and a few of them showed recombined morphology of the parental strains. The highest yield and biological efficacy (BE) were recorded in GF248, while least in GF244. The hybridity of the fusant was established based on mycelia, fruiting morphology, and PCR fingerprinting. ISSR and RAPD profile analysis of ten fusants and parents depicted that fusants contained polymorphic bands, which specified the rearrangement and deletion of DNA in the fusants. A Dendrogram was constructed based on the RAPD profile, and the clustering data exhibited two major clusters: cluster I included the G. lingzhi and Cluster II, including the G. applanatum and fusant lines. Total polysaccharide (α, β and total glucan) content was compared with fusants and parental strains. The present study highlighted the efficient methods for protoplast isolation from Ganoderma species. PEG-induced fusants showed high polymorphic frequency index, while the phenotypic characters showed high similarity to G. applanatum. A significant difference was observed in the mushroom yield and its total polysaccharide between the fusants and parental strains.

Biologically active polysaccharide from edible mushrooms: A review

Mushrooms are renewable natural gift for humankind, furnished with unique taste, flavor and medicinal properties. For the last few decades study of mushroom polysaccharides has become a matter of great interest to the researchers for their immunomodulating, antimicrobial, antioxidant, anticancer, and antitumor properties. Molecular mass, branching configuration, conformation of polysaccharides and chemical modification are the major factors influencing their biological activities. The mechanism of action of mushroom polysaccharides is to stimulate T-cells, B-cells, natural killer cells, and macrophage dependent immune responses via binding to receptors like the toll-like receptor-2, dectin-1. The present review offers summarized and significant information about the structural and biological properties of mushroom polysaccharides, and their potential for development of therapeutic materials.

Structural studies of a water insoluble β-glucan from Pleurotus djamor and its cytotoxic effect against PA1, ovarian carcinoma cells

A water insoluble β-glucan (PS), with molecular mass ∼9.16 × 10⁴ Da was isolated from the 4% alkaline extract of an edible mushroom, Pleurotus djamor and found to consist of (1→3)-β-d-glucopyranosyl moiety. The structure of the PS was elucidated on the basis of total hydrolysis, methylation analysis, periodate oxidation, and NMR experiments (¹H, ¹³C, DQF-COSY, DEPT-135, and HSQC). The structure of the repeating unit of the polysaccharide was established as: →3)-β-d-Glcp-(1→. The water insoluble β-glucan showed cytotoxic effect against PA1 cells, where˜50% population was destroyed at 100 μg/mL concentration, and almost all cells at 250 μg/mL concentration. The wound healing assay showed significant anticarcinogenic effect against ovarian carcinoma PA1 cells after 48 h of treatment.

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)-β-d-glucopyranosyl residues, one (1→4)-α-d-mannopyranosyl residue, and two (1→3)-β-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.

Isolation and characterization of extracellular polysaccharide Thelebolan produced by a newly isolated psychrophilic Antarctic fungus Thelebolus

The present investigation is on a newly isolated psychrophilic Antarctic filamentous Ascomycetous fungus that has been identified as Thelebolus sp. and given the designation of Thelebolus sp. IITKGP-BT12. The culture was primarily identified through morphological studies, and was further confirmed by 18S rRNA sequencing (GenBank Accession No. KC191572), which revealed its close relatedness with Thelebolus microsporus. The exopolysaccharide (EPS) produced (1.94 g L(-1)) by the fungus was isolated, purified and characterized as glucan having an average molecular mass of 5×10(5)Da. The structure of EPS was determined by gas chromatography with tandem mass spectrometry (GC-MS/MS), Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR) studies ((1)H, (13)C and HSQC). NMR analysis indicated the presence of (1→3)-linked β-d-glucan backbone with (1→6)-linked branches of β-d-glucopyranosyl units. Antiproliferative activity of EPS was demonstrated in B16-F0 cells, with IC50 of 275.42 μg m L(-1). Flow cytometry analysis and DNA fragmentation studies revealed that the cytotoxic action of the EPS mediated apoptosis in cancer cells. This is the first ever report on bioactive EPS thelebolan from Thelebolus sp.

The physicochemical properties of a new class of anticancer fungal polysaccharides: a comparative study

The structural and physicochemical properties of polysaccharides isolated from fungi with anticancer properties were investigated. The majority of the polysaccharides considered, have the β-d-Glcp component mostly connected by 1→3 and 1→6 linkages in the backbones and the short branches, respectively. The established parameters of lead-like, drug-like and of known dug space (KDS) were used and the repeating units of the polysaccharides exhibit some overlap with these. It was found that a unique region of chemical space is occupied by the polysaccharides, with MW: 1.0 x 10(5) to 2.5 x 10(5) g mol(-1); LogP: -3.0 x 10(3) to -1.0 x 10(3); HD: 1.0 x 10(3) to 5.0 x 10(3); HA: 5.0 x 10(3) to 1.0 x 10(4); PSA: 5.0 x 10(4) to 1.0 x 10(5) and RB: 5.0 x 10(3) to 1.0 x 10(4). These findings can be exploited in antitumor drug discovery projects.