Polysaccharides from Hericium erinaceus Fruiting Bodies: Structural Characterization, Immunomodulatory Activity and Mechanism.

Five fractions from crude Hericium erinaceus polysaccharides (HEPs), including HEP-1, HEP-2, HEP-3, HEP-4 and HEP-5, were obtained through column chromatography with a DEAE Cellulose-52 column and Sephadex G-100 column. The contents of total carbohydrates and uronic acid in HEPs were 53.36% and 32.56%, respectively. HEPs were mainly composed of Fuc, Gal and Glu in a molar ratio of 7.9:68.4:23.7. Its chemical structure was characterized by sugar and methylation analysis, along with 1H and 13C NMR spectroscopy. HEP-1 contains the backbone composed of (1→6)-linked-galactose with branches attached to O-2 of some glucose. The immunological activity assay indicated that HEP-1 significantly promoted the production of nitric oxide, interleukin-6, interleukin-10, interferon-γ and tumor necrosis factor-α and the phosphorylation of signaling molecules. Collectively, these results suggested that HEP-1 could improve immunity via NF-κB, MAPK and PI3K/Akt pathways. Hericium erinaceus polysaccharides might be explored as an immunomodulatory agent for use in dietary supplements.

Extraction, structural characterization, and physicochemical properties of polysaccharide from purple sweet potato.

The polysaccharide from purple sweet potato (PPSP) was extracted. The structure was characterized and partial physicochemical properties were described of PPSP via UV, IR, NMR, XRD, DSC-TGA, LDS, and Congo red assay. This study provided a theoretical basis for the in-depth structural analysis of PPSP and the study of its biological activity.

Value added immunoregulatory polysaccharides of Hericium erinaceus and their effect on the gut microbiota.

Hericium erinaceus polysaccharides (HEPs) were isolated from the fruiting bodies of H. erinaceus with 53.36 % total carbohydrates and 32.56 % uronic acid. To examine whether HEPs can alter the diversity and the abundance of gut microbiota, adult mice and middle-aged and old mice were fed with HEPs for 28 days. Based on the result of 16S sequencing of gut microbiota it was found that the relative abundances of Lachnospiraceae and Akkermansiaceae significantly increased, while the relative abundance of Rikenellaceae and Bacteroidaceae appeared to decrease. Bacterial solutions from different murine intestinal segments and feces were collected to ferment HEPs in vitro. It was found that HEPs remarkably promoted the production of NO, IL-6, IL-10, INF-γ and TNF-α. Moreover, HEPs significantly increased phosphorylation of signaling molecules, indicating that the immunomodulatory activity was completed via NF-кB, MAPK and PI3K/Akt pathways. Collectively, HEPs have potential to be developed as functional ingredients or foods to promote health.

Structural differences of polysaccharides from Astragalus before and after honey processing and their effects on colitis mice.

Honey-processed Astragalus is a dosage form of Radix Astragali processed with honey, which exhibits better efficacy of tonifying Qi than the raw product. Polysaccharides are its main water-soluble active components. This work was designed to study the structural differences of homogeneous honey-processed Astragalus polysaccharides (HAPS3a) and Astragalus polysaccharides (APS3a) and their effects on colitis mice. The results showed that HAPS3a (Mw = 2463.5 kDa) and APS3a (Mw = 3373.2 kDa) differed in molecular weight, monosaccharide compositions, glycosidic bonds and degree of branching (DB). Notably, the molar ratios of galactose and galacturonic acid in HAPS3a were 22.66% and 33.24%, while those in APS3a were 11.87% and 49.55%, respectively. The uronic acid residues 1,4-ß-GalpA and 1,6-α-GlcpA of the backbone in APS3a were converted into the corresponding neutral residues in HAPS3a after honey processing. The different DB of HAPS3a (15.35%) and APS3a (25.13%) suggested that the chain conformation became smoother. The anti-inflammatory effects on colitis mice revealed that HAPS3a exhibited better effects than APS3a by protecting intestinal mucosa, regulating the expression of cytokines and influencing microbiota diversity. Taken together, the differences in anti-inflammatory activity might be related to structural differences caused by honey processing. Our findings have laid a foundation for the processing mechanism of Astragalus.

Formation pathways and precursors of furfural during Zhenjiang aromatic vinegar production.

As a flavor and quality parameter, furfural has potential undesirable effects. This study aimed to elucidate furfural formation, including generation, pathways, and possible precursors during the production of Zhenjiang aromatic vinegar. A cereal vinegar model, rich in saccharides, amino acids, and organic acids, was used to explore the potential precursors. Furfural and 5-hydroxymethylfurfural (HMF) mainly generated during the decoction process, but the HMF also increased during the aging process. Three pathways were found to coexist for the formation of furfural: (i) the Maillard reaction induced by saccharides and nitrogenous compounds, (ii) the direct cleavage of pentose, and (iii) indirect conversion from pentosan, which only made a minor contribution. Furfural was not formed from HMF or l-ascorbic acid in vinegar. Instead, ribose, xylose, arabinose, galacturonic acid, glucuronic acid, and pentosan were the main precursors. These insights may be useful for the risk/benefit balance and improve the flavor quality and safety.

D-rhamnan and teichuronic acid from the cell wall of Rathayibacter caricis VKM Ac-1799T.

The cell wall of Rathayibacter caricis VKM Ac-1799T (family Microbacteriaceae, class Actinobacteria) was found to contain both neutral and acidic glycopolymers. The first one is D-rhamnopyranan with main chain →2)-α-D-Rhap-(1 â†’ 3)-α-D-Rhap-(1→, where a part of 2-substituted residues bears as a side-chain at position 3 α-D-Manp residues or disaccharides α-D-Araf-(1→2)-α-D-Manp-(1 â†’ . The second polymer is a teichuronic acid with a branched repeating units composed of seven monosaccharides →4)-α-[ß-D-Manp-(1 â†’ 3)]-D-Glcp-(1 â†’ 4)-ß-D-GlcpA-(1 â†’ 2)-ß-[4,6Pyr]-D-Manp-(1 â†’ 4)-ß-L-Rhap-(1 â†’ 4)-ß-D-Glcp-(1 â†’ 4)-ß-D-Glcp-(1 â†’ . The structures of the polymers were determined by chemical and NMR spectroscopic methods.

Increased antioxidant activity and improved structural characterization of sulfuric acid-treated stepwise degraded polysaccharides from Pholiota nameko PN-01.

The aim of this study was to investigate sulfuric acid degradation of the Pholiota nameko polysaccharide (AIPS-1). Three stepwise degraded polysaccharides (AIPS-2, AIPS-3, and AIPS-4) were obtained by sequentially increasing the strength of sulfuric acid treatment. Structural characterization showed that sulfuric acid treatment significantly decreased molecular weight, increased the content of uronic acid and changed the molar ratio of monosaccharide composition, while the major functional groups and the triple helical conformation of polysaccharides did not change significantly. In vitro experiments proved that the antioxidation ability of the stepwise degraded polysaccharides gradually increased (AIPS-1 < AIPS-2 < AIPS-3 < AIPS-4). An oxidative stress zebrafish model was established, which demonstrated that the ability of AIPS-3 and AIPS-4 to scavenge free radicals in zebrafish was significantly improved compared to AIPS-1. In conclusion, sulfuric acid treatment is an effective method for improving the antioxidant activity of polysaccharides, and increased antioxidant activity was closely related to the changes in their structural characteristics.

Production, physicochemical characteristics, and in vitro biological activities of polysaccharides obtained from fresh bitter gourd (Momordica charantia L.) via room temperature extraction techniques.

In this study, polysaccharides (BPSs) were obtained from fresh bitter gourd (Momordica charantia L.) by room temperature extraction techniques, including three-phase partitioning (TPP) and ultrasonic-assisted extraction (UAE) performed in different solvents. The results showed that the extraction methods had significant influence on the extraction yield, chemical composition, weight-average molecular weight (Mw), monosaccharide composition, preliminary structural characterization and microstructure of the BPSs. The BPS-W sample obtained from the bitter gourd residue via UAE in distilled water had a higher uronic acid content (24.22%) and possessed stronger antioxidant capacities and α-amylase and α-glycosidase inhibitory activities than BPS-C extracted with UAE in citric acid, BPS-A extracted with UAE in 1.25 mol/L NaOH/0.05% NaBH4, and BPS-J extracted from bitter gourd juice by TPP. Moreover, BPS-A, which had the lowest Mws, showed the best bile acid-binding capacity among the four BPSs. This study had great potentials for the preparation of bioactive polysaccharides from fresh vegetables.

Chemical characteristic and bioactivity of hemicellulose-based polysaccharides isolated from Salvia miltiorrhiza.

Salvia miltiorrhiza roots (SMRs), the main component of cell wall from the residual waste extraction, differ depending on the forming ways of monosaccharides. The extraction from 8% sodium hydroxide solution (H-8) was characterized by gel permeation chromatography (GPC), monosaccharide composition, Fourier transform infrared spectroscopy (FT-IR), and nuclear magnetic resonance (NMR) spectroscopy. The structure model of hemicellulose-based polysaccharides (HBPs) was derived by combining one-dimensional and two-dimensional NMR. Monosaccharides difference and correlation were performed by partial least square analysis (PLS). Seven H-8s exhibited optimal inhibitory activities, which varied based on different sources of Danshen. The backbone structure indicated that 4-ß-D-Xylp served as the main chain connected by 3-α-L-Araf or 5-α-L-Araf-1, 4-ß-D-Galp, and ß-D-Glcp branch, as well as α-L-Rhap, α-D-GalpA and α-D-GlcpA fragments. The variation of HBPs in terms of the structure and bioactivity of SMRs correlated with different cultivation sites can be a new approach to optimize and utilize the medical materials by chemical and biological aspects of natural macromolecules.

Ultrafiltration isolation, physicochemical characterization, and antidiabetic activities analysis of polysaccharides from green tea, oolong tea, and black tea.

Both fermentation degree and preparation method of polysaccharides could influence the bioactivity of tea polysaccharides. The aim of this study was to compare the physicochemical characterization and biological activities of the polysaccharides isolated by ultrafiltration method from three kinds of tea (green tea, oolong tea, and black tea). The bioactivities of tea polysaccharide fractions were compared from four aspects, including antioxidant activities, antiglycation activities, α-glucosidase inhibitory capability, and hypoglycemic effects on L6 myotubes. Results showed that six polysaccharides (GTPS1, GTPS2, OTPS1, OTPS2, BTPS1, and BTPS2) had different contents of neutral sugar and uronic acid, and they showed different morphologies. Six polysaccharides were composed of the seven monosaccharides with different molar ratios. BTPS1 exhibited the highest DPPH scavenging activity and hydroxyl radical scavenging activity (P < 0.05), and BTPS1 also showed the strongest antiglycation inhibitory effects (P < 0.05). BTPS1 and BTPS2 showed strong inhibitory capacity on α-glucosidase and hypoglycemic effects in L6 skeletal muscle cells. The result suggested that the degree of fermentation of tea could improve their bioactivities (BTPS > OTPS >GTPS), and TPS1 with smaller molecular weight distribution showed higher bioactivities than TPS2. This study can provide a scientific foundation for the application of tea polysaccharides and related functional products.

Structure feature and antidepressant-like activity of a novel exopolysaccharide isolated from Marasmius androsaceus fermentation broth.

The structure and antidepressant like activity of MEPS2 extracted from Marasmius androsaceus subjected to submerged fermentation was systematically studied. MEPS2 is a pyranoid polysaccharide composed of glucose and arabinose, which have a molar ratio of 0.56:0.08. The molecular weight was 85,944 Da. The NMR spectrum suggested the extracted MEPS2 contained uronic acid, and the glucosyl linkage was in α form, in accordance with the analysis of FT-IR spectrum. MEPS2 can considerably enhance the levels of noradrenalin (NE) and dopamine (DA) by ELISA. In addition, western blotting results indicated that MEPS2 can enhance the expression levels of TH, D2DR, and CAMKII. Furthermore, we found that AMPT, raclopride, and prazosin blocked the immobility and time-reducing effect of MEPS2. Overall, the antidepressant-like effect of MEPS2 may be involved in catecholamine synthesis and release, and TH, D2DR and CAMKII play an important role in this process.

The activation of NF-κB and MAPKs signaling pathways of RAW264.7 murine macrophages and natural killer cells by fucoidan from Nizamuddinia zanardinii.

Polysaccharides from Nizamuddinia zanardinii were extracted using water at elevated temperature and fractionated by a DEAE Sepharose FF column yielding four fractions (F1-F4). Crude and fractions were composed of neutral sugars (50.8-57.4%), proteins (10.8-18.1%), sulfates (7.5-17.3%) and uronic acids (3.5-7.7%). Various levels of galactose (13.4-44.4%), fucose (34.1-40.1%), mannose (14.1-33.2%) and xylose (7.4-15.2%) formed the building blocks of the polysaccharide structures. The weight average molecular weights (Mw) of polysaccharides varied between 40.3 and 1254.4 × 103 g/mol. F3 polysaccharide was the most active fraction stimulating RAW264.7 murine macrophage cells to secrete NO, TNF-α, IL-1ß and IL-6, and activating NK cells to release TNF-α, INF-γ, granzyme-B, perforin, NKG2D and FasL through NF-κB and MAPKs signaling pathways. Highly-branched F3 polysaccharide mainly consisted of (1 â†’ 2)-Fucp, (1 â†’ 2,3)-Manp, (1 â†’ 3)-Galp, (1 â†’ 2)-Manp, (1 â†’ 3)-Manp, (1 â†’ 2,3,4)-Manp and (1 â†’ 2,3,6)-Manp residues with great amount of (→1)-Fucp and (→1)-Xylp. Sulfates substituted at C-2 of fucose and galactose residues. Overall, fucoidan from N. zanardinii showed immense potency in boosting immune system through macrophages and NK cells activations and therefore suitable for further exploration in immune-mediated biomedical applications.

Structural features of an acidic polysaccharide with the potential of promoting osteoblast differentiation from Lycium ruthenicum Murr.

The enhanced osteoblast differentiation is beneficial to the prevention of osteoporosis. In this study, a homogeneous polysaccharide (LRP-S2A) with the potential of promoting osteoblast differentiation was obtained from the fruits of Lycium ruthenicum, a traditional herb for treatment of postmenopausal metabolic disorders. Structural identification indicated that LRP-S2A, with a relative molecular weight of 2.65 × 106 Da and an uronic acid content of 41.8%, contained Rha, Ara, Gal, Glc and GlcA in a molar ratio of 1.00 : 2.07 : 0.57 : 2.59 : 4.33 and was composed of a backbone consisting of 6-O-Me-α-(1→4)-D-GlcpA, 2-O-acetyl-α-(1→4)-D-Glcp, α-(1→2,4)-L-Rhap, ß-(1→3)-D-Galp andα-(1→3,5)-L-Araf, and some branches consisting of 6-O-Me-α-(1→4)-D-GlcpA and terminal α-L-Araf. These results suggested that LRP-S2A with the potential of promoting osteoblast differentiation was a new acidic polysaccharide.

Identification and Characterization of Citrus Peel Uronic Acid Oxidase.

Uronic acid-rich plant materials such as pectin are potential renewable feedstocks for the chemical industry. Uronic acid oxidase activity was first reported in extracts of citrus leaves, and was subsequently found to be widely distributed in plants, with the highest activity detected in extracts of the pectin-rich citrus peel. Herein we report the identification of the primary sequence of uronic acid oxidase from extracts of the peel of Citrus sinensis, by partial purification and protein mass spectrometry. Activity of the enzyme, a member of the berberine bridge family, was confirmed by recombinant expression in Pichia pastoris. Biochemical characterization of the recombinant enzyme is reported. Our findings facilitate further investigation of the biological function of uronic acid oxidation in the economically important orange fruit, and also provide a basis for the development of a catalyst for bioconversion of uronic acids.

Purification, characterization and functional properties of exopolysaccharide from a novel halophilic Natronotalea sambharensis sp. nov.

An exopolysaccharide producing strain AK103T was isolated from Sambharlake, Rajasthan, India. Based on polyphasic taxonomy, the strain AK103T was found to be a novel species for which the name Natronotalea sambharensis sp. nov. is proposed. The strain was able to secrete (1.2 gL-1) EPS under optimum conditions. The FT-IR spectroscopy revealed that EPS had carboxyl, hydroxyl, carbonyl and sulfate ester groups. The high performance liquid chromatography (HPLC), gel permeation chromatography (GPC) and NMR revealed that the exopolysaccharide was composed of mannose, glucose and glucuronic acid with a molecular weight of 4.6 × 106 KDa. This novel EPS was designated as Nat-103. Interestingly, the EPS was found to have antioxidant activity and in vitro antioxidant studies showed that DPPH (2,2-diphenyl-1-picrylhydrazyl) activity increased in a dose dependent manner. Furthermore, EPS Nat-103 was able to produce gold nanoparticles which were further characterized by FT-IR, DLS and Zeta potential (ZP).

Characterization of physicochemical properties and antioxidant activity of polysaccharides from shoot residues of bamboo (Chimonobambusa quadrangularis): Effect of drying procedures.

In the present study, the bamboo shoot (Chimonobambusa quadrangularis) residue (BSR)-derived polysaccharides (CPS) were dried using different drying procedures, including hot air-, vacuum-, freeze-, and spray-drying. The influences of different drying procedures on the chemical compositions, physicochemical characteristics, and antioxidant activity of CPS were investigated. The results indicate that freeze-dried CPS possessed the highest polysaccharide yield (8.86%) and uronic acid content (9.42%), and the lowest medium-high molecular weight (117.49 kDa) and glucose content (5.81 mol%). Also, freeze-dried CPS had better water (5.17 g/g) and oil retention capacities (2.32 g/g) than hot air- and vacuum-dried CPS. Moreover, freeze-dried CPS exhibited the most potent antioxidant ability. Based on correlation analysis, a higher uronic acid content, lower molecular weight and lower glucose content might be closely associated with the better antioxidant activity of the freeze-dried CPS. Hence, the above results revealed freeze-drying was the optimal method for industrial production of high quality CPS.

Synthesis and characterization of porous tree gum grafted copolymer derived from Prunus cerasifera gum polysaccharide.

Porous grafted copolymer with excellent thermal stability and swelling capacity was synthesized from water soluble Prunus cerasifera gum polysaccharide (PG) and acrylamide (AM). The monosaccharide compositions and the structure of Prunus cerasifera tree gum were detected by a high-performance anion exchange chromatography (HPAEC) system and 1H NMR and 13C NMR, and the obtained PG-AM copolymer was characterized by Fourier transform infrared (FT-IR), scanning electron microscope (SEM), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. The results indicated that the water soluble polysaccharides obtained from Prunus cerasifera tree gum were mainly composed of l-arabinose (39.78%) and d-galactose (40.59%) with minor amount of xylose, mannose and uronic acids. The maximum percent and the grafting efficiency of grafting acrylamide (AM) onto PG to form PG-AM were obtained by copolymerization between polysaccharide and 3 times (weight) acrylamide with 3 mmol/L potassium persulfate initiator at 50 °C for 1 h. In addition, lots of isolated and conjoint pores were observed in the prepared PG-AM materials, with a diameters distribution between 2 and 10 µm. Compared with PG, the synthesized copolymer PG-AM showed an excellent performance in thermal stability and swelling capacity. The detailed structural characteristic together with excellent thermal stability and swelling properties will benefit efficient utilization of the synthesized copolymer as a precursor for preparation of large-scale environmentally friendly advanced materials with various potential applications.

Flocculating, emulsification and metal sorption properties of a partial characterized novel exopolysaccharide produced by Rhizobium tropici SRA1 isolated from Psophocarpus tetragonolobus (L) DC

A novel exopolysaccharide (EPS) was produced by a bacterium which was isolated from Psophocarpus tetragonolobus (L) D.C. and identified as 99% Rhizobium tropici SRA1 by 16S rDNA sequencing. The flocculating performances along with emulsifying activity began simultaneously with the growth and the production of EPS and reached its utmost at 28 h. EPS was purified via chilled ethanol precipitation followed by dialysis and lyophilization. The existence of hydroxyl, methoxyl, and carboxylic functional groups were confirmed by Fourier transform infrared (FT-IR) spectrum. EPS was found to be compose of 82.44% neutral sugar and 15.93% uronic acid. The average molecular weight of the exopolysaccharide was estimated as ~1.8×105. Gas-liquid chromatography indicated the presence of glucose and galactose at a molar ratio of 3:1 in EPS. In the pH range of 3-5 with EPS dosage of 15 mg/l at 30 °C, cation-independent flocculation greater than 90% was observed. Emulsification indices (E24) of EPS were observed as 86.66%, 83.33%, 76.66%, and 73.33% with olive oil, kerosene, toluene, and n-hexane respectively. Biosorption of Cu K [45.69 wt%], Cu L [05.67 wt%], Co K [15.58 wt%], and Co L [11.72 wt%] by EPS was confirmed by energy-dispersive X-ray spectroscopy (EDS). This report on the flocculating, emulsifying, and metal sorption properties of EPS produced by R. tropici SRA1 is unique in the literature

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Flocculating, emulsification and metal sorption properties of a partial characterized novel exopolysaccharide produced by Rhizobium tropici SRA1 isolated from Psophocarpus tetragonolobus (L) D.C.

A novel exopolysaccharide (EPS) was produced by a bacterium which was isolated from Psophocarpus tetragonolobus (L) D.C. and identified as 99% Rhizobium tropici SRA1 by 16S rDNA sequencing. The flocculating performances along with emulsifying activity began simultaneously with the growth and the production of EPS and reached its utmost at 28 h. EPS was purified via chilled ethanol precipitation followed by dialysis and lyophilization. The existence of hydroxyl, methoxyl, and carboxylic functional groups were confirmed by Fourier transform infrared (FT-IR) spectrum. EPS was found to be compose of 82.44% neutral sugar and 15.93% uronic acid. The average molecular weight of the exopolysaccharide was estimated as ~ 1.8 × 105. Gas-liquid chromatography indicated the presence of glucose and galactose at a molar ratio of 3:1 in EPS. In the pH range of 3-5 with EPS dosage of 15 mg/l at 30 °C, cation-independent flocculation greater than 90% was observed. Emulsification indices (E24) of EPS were observed as 86.66%, 83.33%, 76.66%, and 73.33% with olive oil, kerosene, toluene, and n-hexane respectively. Biosorption of Cu K [45.69 wt%], Cu L [05.67 wt%], Co K [15.58 wt%], and Co L [11.72 wt%] by EPS was confirmed by energy-dispersive X-ray spectroscopy (EDS). This report on the flocculating, emulsifying, and metal sorption properties of EPS produced by R. tropici SRA1 is unique in the literature.

Study on the kinetic model, thermodynamic and physicochemical properties of Glycyrrhiza polysaccharide by ultrasonic assisted extraction.

The extraction process of crude polysaccharides from Glycyrrhiza (GP) by ultrasonic assisted hot water method was established according to the optimized kinetic model based on Fick's second law of diffusion, and thermodynamic action was analyzed. Physicochemical properties of GP including the apparent viscosity, thermostability and antioxidant activities etc. were determined by ultraviolet spectrophotometry and differential scanning calorimetry (DSC). Characteristic function groups and surface structure also were analyzed by Fourier infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. The results showed the extraction kinetic curves of GP showed good linear correlation with the linear correlation coefficients (R2) of equal or greater than 0.90 based on Fick's second law of diffusion, and the maximum yield of 3.53% was obtained at 343.15 K and ultrasonic power 600 W with material-liquid ratio of 1:15 for 60 min. Gibbs free energy change (ΔGm > 0) indicated that the extraction process was endergonic and not spontaneous. GP was confirmed a kind of acidic pyran polysaccharide with small bubble-like holes internally. The GP viscosity increased with the increase of concentration and then gradually decreased with the enhancement of shear rate. GP showed good thermal stability along with two stages of mass loss by DSC analysis. The antioxidant activity experiments suggested that the higher the concentration of GP, the stronger its reduction power.