Glucan polysaccharides isolated from Lactarius hatsudake Tanaka mushroom: Structural characterization and in vitro bioactivities.

Commercially available mushroom polysaccharides have found widespread use as adjuvant tumor treatments. However, the bioactivity of polysaccharides in Lactarius hatsudake Tanaka (L. hatsudake), a mushroom with both edible and medicinal uses, remains relatively unexplored. To address this gap, five L. hatsudake polysaccharides with varying molecular weights were isolated, named LHP-1 (898 kDa), LHP-2 (677 kDa), LHP-3 (385 kDa), LHP-4 (20 kDa), and LHP-5 (4.9 kDa). Gas chromatography-mass spectrometry, nuclear magnetic resonance, and atomic force microscopy, etc., were employed to determine their structural characteristics. The results confirmed that spherical aggregates with amorphous flexible fiber chains dominated the conformation of the LHP. LHP-1 and LHP-2 were identified as glucans with α-(1,4)-Glcp as the main chain; LHP-3 and LHP-4 were classified as galactans with varying molecular weights but with α-(1,6)-Galp as the main chain; LHP-5 was a glucan with ß-(1,3)-Glcp as the main chain and ß-(1,6)-Glcp connecting to the side chains. Significant differences were observed in inhibiting tumor cell cytotoxicity and the antioxidant activity of the LHPs, with LHP-5 and LHP-4 identified as the principal bioactive components. These findings provide a theoretical foundation for the valuable use of L. hatsudake and emphasize the potential application of LHPs in therapeutic tumor treatments.

An antitumor fungal polysaccharide from Fomitopsis officinalis by activating immunity and inhibiting angiogenesis.

Macrofungi, a class of unique natural resources, are gaining popularity owing to their potential therapeutic benefits and edibility. From Fomitopsis officinalis, a medicinal macrofungus with anticancer activity, a homogeneous heteropolysaccharide (FOBP50-1) with a molecular weight of 2.21 × 104 g/mol has been extracted and purified. FOBP50-1 was found to be composed of 3-O-methylfucose, fucose, mannose, glucose, and galactose with a ratio of 1: 6.5: 4.4: 8.1: 18.2. The sugar fragments and structure of FOBP50-1 were investigated, which included →6)-α-d-Galp-(1→, →2,6)-α-d-Galp-(1→, →3)-α-l-Fucp-(1→, α-d-Glcp-(1→, →3)-ß-d-Manp-(1→, →6)-ß-d-Manp-(1→, 3-O-Me-α-l-Fucp-(1→, according to the UV, FT-IR, GC-MS, and NMR data. Besides the structure elucidation, FOBP50-1 showed promising antitumor activity in the zebrafish assays. The following mechanism examination discovered that FOBP50-1 interacted with TLR-4, PD-1, and VEGF to activate immunity and inhibit angiogenesis according to a series of cell, transgenic zebrafish, and surface plasmon resonance (SPR) experiments. The KD values indicating the association of FOBP50-1 with TLR-4, PD-1, and VEGF, were 4.69 × 10-5, 7.98 × 10-6, 3.04 × 10-6 M, respectively, in the SPR experiments. All investigations have demonstrated that the homogenous fungal polysaccharide FOBP50-1 has the potential to be turned into a tumor immunotherapy agent.

Identification and Quantification of Monosaccharides from Fungal Cell Walls and Exopolysaccharides by Gas Chromatography Coupled to Mass Spectrometry.

The fungal cell wall and secreted exopolysaccharides play an important role in the interactions between fungi and their environment. Despite their central role in fungal biology, ecology, and host-pathogen interactions, the composition of these polymers and their synthetic pathways are not well understood. The protocols presented in this article describe an approach to isolate fungal cell wall polysaccharides and to identify and quantify the monosaccharide composition of these polymers by gas chromatography-mass spectrometry (GC-MS). © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol: O-methyl trimethylsilyl monosaccharide derivatives composition analysis by GC-MS Support Protocol: Fungal cell wall extraction.

Characterization and immunomodulatory effect of an alkali-extracted galactomannan from Morchella esculenta.

In our continuous exploration for bioactive polysaccharides, a novel polysaccharide FMP-2 was isolated and purified from the fruiting bodies of Morchella esculenta by alkali-assisted extraction. FMP-2 had an average molecular weight of 1.09 × 106 Da and contained mannose, glucuronic acid, glucose, galactose, and arabinose in a molar ratio of 4.10:0.22:1.00:5.75:0.44. The backbone of FMP-2 mainly consisted of 1,2-α-D-Galp, 1,6-α-D-Galp, and 1,4-α-D-Manp, with branches of 1,4,6-α-D-Manp and 1,2,6-α-D-Galp. FMP-2 can stimulate phagocytosis and promote the secretion of NO, ROS, and cytokines like IL-6, IL-1ß, and TNF-α in RAW264.7 cells ranging from 25 to 400 µg/mL. FMP-2 had great repairing effect on the immune injury of zebrafish induced by chloramphenicol. The phagocytosis ability of zebrafish macrophages and the proliferation of neutrophils can be greatly enhanced by polysaccharide FMP-2 with concentrations from 50 to 200 µg/mL. These findings suggest that FMP-2 might be used as a potential immunomodulator in the food and pharmaceutical industries.

Selenium-Containing Exopolysaccharides Isolated from the Culture Medium of Lentinula edodes: Structure and Biological Activity.

In continuation of our research on the influence of selenium incorporation on the biosynthesis, structure, and immunomodulatory and antioxidant activities of polysaccharides of fungal origin, we have isolated from a post-culture medium of Lentinula edodes a selenium (Se)-containing exopolysaccharide fraction composed mainly of a highly branched 1-6-α-mannoprotein of molecular weight 4.5 × 106 Da, with 15% protein component. The structure of this fraction resembled mannoproteins isolated from yeast and other mushroom cultures, but it was characterized by a significantly higher molecular weight. X-ray absorption fine structure spectral analysis in the near edge region (XANES) suggested that selenium in the Se-exopolysaccharide structure was present mainly at the IV oxidation state. The simulation analysis in the EXAFS region suggested the presence of two oxygen atoms in the region surrounding the selenium. On the grounds of our previous studies, we hypothesized that selenium-enriched exopolysaccharides would possess higher biological activity than the non-Se-enriched reference fraction. To perform structure-activity studies, we conducted the same tests of biological activity as for previously obtained mycelial Se-polyglucans. The Se-enriched exopolysaccharide fraction significantly enhanced cell viability when incubated with normal (human umbilical vein endothelial cells (HUVEC)) cells (but this effect was absent for malignant human cervical HeLa cells) and this fraction also protected the cells from oxidative stress conditions. The results of tests on the proliferation of human peripheral blood mononuclear cells suggested a selective immunosuppressive activity, like previously tested Se-polyglucans isolated from L. edodes mycelium. The Se-exopolysaccharide fraction, in concentrations of 10-100 µg/mL, inhibited human T lymphocyte proliferation induced by mitogens, without significant effects on B lymphocytes. As with previously obtained Se-polyglucans, in the currently tested Se-polymannans, the selenium content increased the biological activity. However, the activity of selenium exopolysaccharides in all tests was significantly lower than that of previously tested mycelial isolates, most likely due to a different mode of selenium binding and its higher degree of oxidation.

The chemical structure and immunomodulatory activity of an exopolysaccharide produced by Morchella esculenta under submerged fermentation.

The extracellular polysaccharide of Morchella esculenta cultivated under submerged fermentation was extracted. A single polysaccharide was purified through DEAE-Cellulose 52 and Sephadex G 100, and named as MEP 2a. The molecular weight of MEP 2a was determined by HPGPC and it is about 1391.5 kDa. MEP 2a is composed of mannose and glucose as the monosaccharide unit with a molar ratio of 8.15 : 1.07. The main polysaccharide chemical structure was analyzed by 1D and 2D NMR. Methylation and NMR analysis revealed that the backbone of MEP 2a consists of 1,3,4-linked-Manp, 1,2-linked-Manp and 1,6-linked-Glcp. 1D and 2D NMR results indicated that the main chain is based on →1)-ß-D-Glcp-(6→, →1)-α-D-Manp-(3,4→, →1)-α-D-Manp-(2→) and the branch chain is composed of α-D-Manp-(1→, →1)-ß-D-Glcp-(6→ and α-D-Glcp-(1→). MEP 2a promoted the phagocytosis function and secretion of NO, IL-1ß, IL-6 and TNF-α of macrophages. In the present study, the chemical structure and immunomodulatory ability of an extracellular polysaccharide of Morchella esculenta was investigated which guarantees further research studies and promising applications.

Structural characteristics, anti-proliferative and immunomodulatory activities of a purified polysaccharide from Lactarius volemus Fr.

Lactarius volemus Fr. is an edible mushroom widely consumed in China. Polysaccharide is an important nutritional component of L. volemus. This research aimed to isolate the polysaccharide from L. volemus and study its structure and bioactivities. A purified polysaccharide was identified and named as LVF-I whose primary structure was proposed considering the comprehensive results of monosaccharide composition, periodate oxidation-smith degradation, methylation analysis, FT-IR and 1D/2D NMR spectroscopy. Then the immunomodulation of LVF-I and its inhibition effect on H1299 and MCF-7 cells were investigated. Results showed that LVF-I (12,894 Da) contained fucose, mannose, glucose and galactose. It had a backbone consisting of →4)-α-D-Glcp-(1→, →6)-ß-D-Manp-(1→, →6)-α-D-Galp-(1 â†’ and →4)-ß-D-Manp-(1→. And its side chains were branched at C2 of →4)-ß-D-Manp-(1 â†’ by →6)-α-D-Galp-(1→, α-D-Glcp-(1→, α-D-Galp-(1 â†’ and α-L-Fucp-(1→. LVF-I (250-1000 µg/mL) could inhibit the proliferation of H1299 and MCF-7 cells, while enhance the proliferative response of splenocyte and the phagocytic ability of RAW264.7. Furthermore, LVF-I (250-1000 µg/mL) significantly induced the secretion of nitric oxide, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) by up-regulating their mRNA expression in macrophages. These results suggested that LVF-I had the potential to be developed as antitumor or immunomodulatory agents by inhibiting the proliferation of tumor cells and stimulating macrophages-mediated immune responses.

Heteropolysaccharides from S. cerevisiae show anti-adhesive properties against E. coli associated with Crohn's disease.

The Saccharomyces cerevisiae CNCM I-3856 was previously reported to strongly inhibit adherent-invasive Escherichia coli (AIEC) adhesion to intestinal epithelial cells in vitro and to favor AIEC elimination from the gut in a murine model of Crohn's disease in vivo. In order to identify which cell wall components of yeast are responsible for AIEC elimination, constituent polysaccharides of yeast were isolated and their anti-adhesive ability against AIEC adhesion in vitro was screened. A fraction containing mannan, ß-glucan and α-glucan extracted from yeast cell-walls was shown to inhibit 95% of AIEC adhesion in vitro and was thus identified as the strongest anti-adhesive yeast cell wall component. Furthermore, this mannan-glucan-containing fraction was shown to accelerate AIEC decolonization from gut in vivo. This fraction could be proposed as a treatment to eliminate AIEC bacteria in patients with Crohn's disease, a microbial trigger of intestinal inflammation.

Submerged cultivation, characterization and in vitro antitumor activity of polysaccharides from Schizophyllum radiatum.

Production of polysaccharides by white-rot-fungi in submerged cultivation has several advantages due to process control. This work deals with the submerged cultivation, extraction and antitumor activity of polysaccharides from a wild strain of Schizophyllum radiatum isolated from a tropical forest of Colombia. The mushroom was cultivated in laboratory conditions, and classified by classical and molecular taxonomy. Submerged cultivation was performed in a bioreactor of 5 L using a ligninolytic residue as substrate. The fermentation conditions were 30 ± 1 °C, pH 4.5, 300 rpm and 1.5 vvm of air for 4 days. The yields were 16.8 g/L (w/v) of biomass, and after extraction, 0.6 g/L of water-soluble exopolysaccharide (SEPS) and 2.01 % (w/w) of water-soluble intrapolysaccharide (SIPS) were obtained. In each extract total carbohydrate, glucans and protein contents were determined. Also, nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), high performance liquid chromatography with refraction index detection (HPLC-RI), high performance gel permeation chromatography (HPGPC) and Nuclear Magnetic Resonance (NMR) analysis were performed. Results indicated that SEPS and SIPS are heteropolysaccharides with amorphous structure and high molecular weights. Antitumor and immunostimulant activity was evaluated in different cancer cell lines. The results suggest these polysaccharides have direct and indirect antitumor activity activating immune cells such as macrophages. These findings enhance our knowledge about new sources of fungal metabolites that serve as adjuvant, cheaper and less harmful alternatives to cancer treatment.

The lipid lowering and antioxidative stress potential of polysaccharide from Auricularia auricula prepared by enzymatic method.

An efficient extraction method of Auricularia auricula polysaccharides (AAPs) by neutral protease was developed and optimized by response surface methodology. AAPs were graded by stepwise ethanol precipitation, the fraction with high recovery rate and strong radical scavenging rate were obtained, then its antioxidant and lipid lowering effect were studied using Caenorhabditis elegans as model organism. The extract yield and ABTS+ scavenging rates of AAPs could reach 14.90% and 86.0% at 50 °C, 75 mL/g of liquid-to-material ratio and pH 9.0. AAP3 obtained by 15% ethanol was a heteropolysaccharide comprised of mannose, glucose, glucuronic acid, xylose, galactose and glucosamine. AAP3 could significantly prolong the lifespan of C. elegans and enhance the activity of antioxidant enzymes including superoxide dismutase (SOD), catalases (CAT) at 0.25 mg/mL (p < 0.05). The qRT-PCR results showed that AAP3 could up regulate mRNA expression levels of daf-16 and skn-1 (>1.6 fold) at 0.25 mg/mL. Besides, AAP3 could significantly reduce the level of body fat and triglyceride in C. elegans (p < 0.05). These studies demonstrated that A. auricula polysaccharides prepared by neutral protease had a prominent protective effect to the damage induced by the intracellular free radical generating agents.

Polysaccharides and extracts from Agaricus brasiliensis Murill - A comprehensive review.

Edible mushrooms have been increasingly introduced into the human diet, which has driven research into their functional properties. Thus, Agaricus brasiliensis Murill or Agaricus blazei Murill (ABM) is a species native to the Brazilian biome, whose fruiting body has been used not only for dietary purposes, but also in the development of functional foods or as source of molecules of pharmacological interest. The bioactivity of ABM has been related to the presence of polysaccharides, although the contribution of other metabolites cannot be discharged. This work describes the polysaccharides isolation methodology and preparation of the extracts of ABM and their biological activities. Furthermore, it presents a general outline of its characterizations regarding composition, chemical structure and properties in solution. The ABM and its chemical constituents exhibit several biological activities that support their potential use for prevention or treatment of diseases with inflammatory background, such as cancer, diabetes and atherosclerosis. The mechanism of action of the extracts and polysaccharides from ABM is mainly related to a modulation of immune system response or reduction of inflammatory response. This review shows that the ABM has great potential in the pharmaceutical, biotechnological and food sectors that deserves additional research using standardized products.

Recent advances in polysaccharides from Lentinus edodes (Berk.): Isolation, structures and bioactivities.

Lentinus edodes, an important edible mushroom cultivated in East Asia for thousands of years, has been widely used as food and medicinal ingredient worldwide. Modern phytochemistry studies have demonstrated that L. edodes is very rich in bioactive polysaccharides, especially the ß-glucans. Over the past two decades, the isolation, chemical properties, and bioactivities of polysaccharides from fruiting bodies, mycelium and fermentation broth of L. edodes have been drawing much attention from scholars around the world. It has been demonstrated that L. edodes polysaccharides possess various remarkable biological activities, including anti-oxidant, anti-tumor, anti-aging, anti-inflammation, immunomodulatory, antiviral, and hepatoprotection effects. This review summarizes the recent development of polysaccharides from L. edodes including the isolation methods, structural features, bioactivities and mechanisms, and their structure-activity relationship, which can provide useful research underpinnings and update information for their further application as therapeutic agents and functional foods.

Immunomodulatory effect of intracellular polysaccharide from mycelia of Agaricus bitorquis (QuéL.) Sacc. Chaidam by TLR4-mediated MyD88 dependent signaling pathway.

Agaricus bitorquis (QuéL.) Sacc. Chaidam is a valuable edible fungus in Qinghai-Tibet plateau and ABSP is a novel intracellular polysaccharide from its mycelia. GC and NMR analysis determined ABSP is galactoglucomannan-like polysaccharide that may have immunomodulatory effect. This study used RAW264.7 as model cell to determine immunomodulatory effect of ABSP. After ABSP treatment, viability and phagocytic ability promoted, and NO, ROS, TNF-α levels also raised which proved ABSP had immune regulation to RAW264.7. WB and qRT-PCR determined the key proteins and genes expression of TLR4, MyD88, TRAF-6 and NF-κB significantly increased while protein and gene expression of TRAM had no significant increase. Also, TNF-α level extremely decreased by adding inhibitors of TLR4 and MyD88 which confirmed ABSP could immunologically regulate RAW264.7 byTLR4-MyD88 dependent pathway. This study would provide theoretical basis for further study on ABSP and be helpful for development of beneficial functionally foods and exploitation of this resource.

Pink oyster mushroom Pleurotus flabellatus mycelium produced by an airlift bioreactor-the evidence of potent in vitro biological activities.

Four types of mycelial extracts were derived from the airlift liquid fermentation (ALF) of Pleurotus flabellatus, namely exopolysaccharide (EX), endopolysaccharide (EN), hot water (WE), and hot alkali (AE) extracts. Such extracts were screened for their active components and biological potential. EN proved to be most effective in inhibition of lipid peroxidation (EC50 = 1.71 ± 0.02 mg/mL) and in Cupric ion reducing antioxidant capacity (CUPRAC) assay (EC50 = 2.91 ± 0.01 mg TE/g). AE exhibited most pronounced ability to chelate ferrous ions (EC50 = 4.96 ± 0.08 mg/mL) and to scavenge ABTS radicals (EC50 = 3.36 ± 0.03 mg TE/g). ß-glucans and total phenols contributed most to the chelating ability and quenching of ABTS radicals. Inhibition of lipid peroxidation correlated best with total glucans, total proteins, and ß-glucans. Total proteins contributed most to CUPRAC antioxidant capacity. Antifungal effect was determined against Candida albicans ATCC 10231 (MIC: 0.019-0.625 mg/mL; MFC: 0.039-2.5 mg/mL), and towards C. albicans clinical isolate (MIC and MFC: 10.0-20.0 mg/mL). Comparison of cytotoxicity against colorectal carcinoma HCT 116 cells (IC50: 1.8 ± 0.3-24.6 ± 4.2 mg/mL) and normal lung MRC-5 fibroblasts (IC50: 17.0 ± 4.2-42.1 ± 6.1 mg/mL) showed that EN, and especially AE possess selective anticancer activity (SI values 3.41 and 9.44, respectively). Slight genotoxicity was observed only for AE and EX, indicating the low risk concerning this feature. Notable antioxidative and anticandidal activities, selective cytotoxicity against colorectal carcinoma cells, and absence/low genotoxicity pointed out that ALF-cultivated P. flabellatus mycelium could be considered as a valuable source of bioactive substances.

A novel acid polysaccharide from Boletus edulis: extraction, characteristics and antitumor activities in vitro.

A novel cold-water-soluble polysaccharide (BEP), with a molecular weight of 6.0 × 106 Da, was isolated from Boletus edulis. BEP consists of galactose, glucose, xylose, mannose, glucuronic, and galacturonic acid in a ratio of 0.34:0.28:0.28:2.57:1.00:0.44. The IR results showed that BEP was an acid polysaccharide, containing α-type and ß-type glucoside bonds. MTT assay showed BEP could inhibit cell proliferation significantly. Morphological observation demonstrated that BEP-treated MDA-MB-231 and Ca761 cells exhibited typical apoptotic morphological features. Flow cytometry analysis revealed that BEP caused mitochondrial membrane potential collapse. Annexin V-FITC/PI staining indicated that BEP induced apoptosis of MDA-MB-231 and Ca761 cells through cell block in S phase and G0/G1 phase, respectively. Western blot results showed that BEP could increase the Bax/Bcl-2 ratios, promote the release of cytochrome C, and activate the expression of caspase-3 and caspase-9 in MDA-MB-231 and Ca761 cells. In conclusion, our results demonstrated that BEP could inhibit the proliferation of breast cancer cells and induce apoptosis through mitochondrial pathways.

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.

Promising Anti-cancer Therapeutics From Mushrooms: Current Findings and Future Perceptions.

BACKGROUND: Nowadays, medicines derived from natural sources have drawn much attention as potential therapeutic agents in the suppression and treatment of cancer because of their low toxicity and fewer side effects. OBJECTIVE: The present review aims to assess the currently available knowledge on the ethnomedicinal uses and pharmacological activities of bioactive compounds obtained from medicinal mushrooms towards cancer treatment. METHODS: A literature search has been conducted for the collection of research papers from universally accepted scientific databases. These research papers and published book chapters were scrutinized to retrieve information on ethnomedicinal uses of mushrooms, different factors involved in cancer cell proliferation, clinical and in silico pharmaceutical studies made for possible treatments of cancer using mushroom derived compounds. Overall, 241 articles were retrieved and reviewed from the year 1970 to 2020, out of which 98 relevant articles were finally considered for the preparation of this review. RESULTS: This review presents an update on the natural bioactive substances derived from medicinal mushrooms and their role in inhibiting the factors responsible for cancer cell proliferation. Along with it, the present review also provides information on the ethnomedicinal uses, solvents used for extraction of anti-cancer metabolites, clinical trials, and in silico studies that were undertaken towards anticancer drug development from medicinal mushrooms. CONCLUSION: The present review provides extensive knowledge on various anti-cancer substances obtained from medicinal mushrooms, their biological actions, and in silico drug designing approaches, which could form a basis for the development of natural anti-cancer therapeutics.

Structural and immunological studies on the polysaccharide from spores of a medicinal entomogenous fungus Paecilomyces cicadae.

A neutral branched heteropolysaccharide (Pc0-1) was purified from the spores of Paecilomyces cicadae, which parasitized in the bamboo cicada (Platylomia pieli Kato). The structure of Pc0-1 was analyzed by HPLC, IR, methylation and NMR spectroscopy. The results reveal that Pc0-1, with an average molecular weight of 18 × 103 kDa, consists of glucose, galactose, mannose and arabinose in the molar ratio of 8:5:4:1. Some of the glucose residues have methyl modification at O-6 position. The Pc0-1 polysaccharide has a core structure containing 1,2-linked α-d-Manp residues as the backbone and branches at the O-3 and O-6 of the α-d-Manp residues. The inner part of the side-chains is comprised of 1,4-linked α-d-Glcp and 1,4-linked 6-O-Me-α-d-Glcp residues. 1,2-linked ß-Galf and minor 1,4-linked Arap and 1,3 or 4-linked Arap residues were occasionally linked at the outside of the side-chains. The side-chains have a single terminal residue of α-d-Glcp, α-Manp, ß-Galf or minor Arap (minor). Studies on the bioactivity of Pc0-1 on the macrophages show it exhibit moderate immunostimulating activity through increasing the production of nitric oxide (NO) and enhancing the secretion of major inflammatory cytokines by macrophages, such as TNF-α, IL-1ß, IL-6, in RAW 264.7 cells. We examined the effect of Pc0-1 on induced NO and cytokine production in macrophages using anti-PRR antibodies to investigate the membrane receptor for the polysaccharide. The results show that Pc0-1 mainly activates macrophages through their mannose receptor (MR). TLR4 and TLR2 also participated in the recognition of Pc0-1.

Characterization and chemical modification of PLN-1, an exopolysaccharide from Phomopsis liquidambari NJUSTb1.

Phomopsis liquidambari is a classical endophytic fungus with great application potential in ecology and agriculture; however, studies on its exopolysaccharides are lacking. Here, we aimed to evaluate the structure and bioactivity of PLN-1, an exopolysaccharide derived from the P. liquidambari NJUSTb1 strain. The structure was elucidated by chromatography/spectral methods and hydrolyzation. Immunomodulation, moisture absorption, and retention properties were investigated after sulfation and carboxymethylation modification. Results showed that PLN-1 contained a linear repeating unit of →[4)-α-d-Glcp-(1→6)-α-d-Glcp-(1→4)-α-d-Glcp-(1→4)-α-d-Glcp-(1→]n, with a molecular weight of 343 kDa. The degrees of substitution of sulfated polysaccharide (S-PLN-1) and carboxymethylated polysaccharide (C-PLN-1) were 1.228 and 0.903, respectively. S-PLN-1 showed stronger moisture absorption and retention properties than PLN (crude EPS), C-PLN1, and PLN-1. Furthermore, PLN, S-PLN-1, and C-PLN-1 stimulated the proliferation of RAW 264.7 cells with no cytotoxicity. The elucidation of PLN-1 in this study paves the way for future applications.

Polysaccharides from Pleurotus eryngii: Selective extraction methodologies and their modulatory effects on THP-1 macrophages.

Polysaccharides from P. eryngii mushroom were selectively extracted using low-cost technologies (water at different conditions of temperature and pressure). Mannogalactan was the main polysaccharide in cold-water extracted fraction (CWEF), while a linear (1→6)-ß-d-glucan was the main polymer in hot-water extracted fraction (HWEF). Autoclave-extracted fraction (AEF) contained a mixture of at least four different α- and ß-glucans. The report of linear (1→6)-ß-glucan and linear (1→3)-ß-glucan is a new finding for P. eryngii fruiting bodies. The immunostimulatory properties of the fractions on THP-1 macrophages were studied. All fractions at 50, 250 and 500 µg/mL were not cytotoxic and produced different stimulus on NO, IL-1ß and IL-10 secretion by the cells. Thus, our results showed that it is possible to concentrate different P. eryngii polysaccharides in selected fractions using a simple and low-cost procedure. Since biological effects depends on the polysaccharide structure, this technique allows the obtainment of fractions with distinct immunomodulatory activities.