Fractionation, structural characteristics and immunomodulatory activity of polysaccharide fractions from asparagus (Asparagus officinalis L.) skin.

The physicochemical properties, structural features and structure-immunomodulatory activity relationship of pectic polysaccharides from the white asparagus (Asparagus officinalis L.) skin were systematically studied. Using sequential ethanol precipitation, five sub-fractions namely WASP-40, WASP-50, WASP-60, WASP-70 and WASP-80 with distinct degree of esterification (DE) and molecular weight (Mw) were obtained. The Mw and DE values were decreased with the increase of the ethanol concentrations. Structurally, although 4-α-D-GalpA was the dominant sugar residue in all fractions, the molar ratios were decreased, whereas other sugar residues including arabinose- and mannose-based sugar residues overall increased with the increase of ethanol concentration. In addition, the effects of sub-fractions on the RAW 264.7 cells indicated that pectic polysaccharides with the higher DE value showed a stronger immunomodulatory activity. Moreover, the structure-activity relationship was also discussed in this study, which extends the value-added application of asparagus and its processing by-products.

Study on a novel spherical polysaccharide from Fructus Mori with good antioxidant activity.

A novel polysaccharide (MFP1P) was isolated from Fructus Mori, followed by purification via DEAE-52 cellulose and 27 % ethanol fraction. The MFP1P had the molecular weight of 56.78 kDa and the total sugar content of 93.32±0.54 %. And the MFP1P is mainly composed of glucose, galactose, galacturonic acid and mannose with molar ratio of 66.62 %, 13.94 %, 18.24 % and 1.20 %, respectively. MFP1P was mainly composed of →3)-α-D-Gal (1→, ß-D-Man-(1→ and →6)-α-D-Glc (1→ glycosidic bond and showed a spherical chain conformation with uniform distribution in solution. The MFP1P exhibited great antioxidant activity with oxygen-free radical absorption capacity (ORAC) values of 291.63±6.81 µmol TE/g and MDA IC50 of 0.289±0.022 mg/mL.

Glucuronomannan GM2 from Saccharina japonica Enhanced Mitochondrial Function and Autophagy in a Parkinson's Model.

Parkinson's disease (PD), one of the most common neurodegenerative disorders, is caused by dopamine depletion in the striatum and dopaminergic neuron degeneration in the substantia nigra. In our previous study, we hydrolyzed the fucoidan from Saccharina japonica, obtaining three glucuronomannan oligosaccharides (GMn; GM1, GM2, and GM3) and found that GMn ameliorated behavioral deficits in Parkinsonism mice and downregulated the apoptotic signaling pathway, especially with GM2 showing a more effective role in neuroprotection. However, the neuroprotective mechanism is unclear. Therefore, in this study, we aimed to assess the neuroprotective effects of GM2 in vivo and in vitro. We applied GM2 in 1-methyl-4-phenylpyridinium (MPP+)-treated PC12 cells, and the results showed that GM2 markedly improved the cell viability and mitochondrial membrane potential, inhibited MPP+-induced apoptosis, and enhanced autophagy. Furthermore, GM2 contributed to reducing the loss of dopaminergic neurons in 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mice through enhancing autophagy. These data indicate that a possible protection of mitochondria and upregulation of autophagy might underlie the observed neuroprotective effects, suggesting that GM2 has potential as a promising multifunctional lead disease-modifying therapy for PD. These findings might pave the way for additional treatment strategies utilizing carbohydrate drugs in PD.

Optimization, characterization, rheological study and immune activities of polysaccharide from Sagittaria sagittifolia L.

To improve the extraction efficiency of polysaccharides from Sagittaria sagittifolia L. (SPU) by ultrasonic assisted extraction (UAE), the optimal extraction conditions were optimized as follows: extraction temperature of 85℃, extraction time of 15 min and ratio of liquid to raw material 43 mL/g, under these conditions, the yield of SPU increased by about 168 % compared with hot water extraction (HWE). After separation and purification by DEAE-52 cellulose column and Sephadex G-50 column, the pure polysaccharide fraction (SPU70-W1) was obtained, and its structure, rheology and immune activity were analyzed. The results indicated that SPU70-W1 (7.70 kDa) contained mannose, glucose and galactose in the molar ratio of 2.06:93.58:4.36 with typical pseudoplasticity fluids behavior and possessed the backbone of →2,6)-α-D-Glcp-(1→, →3,6)-α-D-Glcp-(1→, α-D-Glcp-(1→ and 6)-α-D-Glcp-(1→. In addition, SPU70-W1 exhibited remarkable immunomodulatory activity. Thus, SPU70-W1 could contribute to the food, medicine, cosmetics as a functional additive.

A high-molecular weight exopolysaccharide from the Cs-HK1 fungus: Ultrasonic degradation, characterization and in vitro fecal fermentation.

This work was to examine the impact of power ultrasound (US) on the molecular properties of a high-molecular weight (MW) exopolysaccharide (EPS) from the Cs-HK1 medicinal fungus and the utilization, and prebiotic function of the US-treated EPS fractions in human fecal microflora in vitro. The US treatment caused notable reduction of intrinsic viscosity, average MW and aggregate size of EPS in water but no significant changes in the molecular structure. The US-treated EPS fractions were consumed more rapidly by the fecal microflora, resulting in a higher total level of short chain fatty acids. They also affected the relative abundance in the microflora more beneficially than the original EPS. The results suggest that power US is effective for modifying and improving the prebiotic properties of high-MW polysaccharides.

Preparation and Neuroprotective Activity of Glucuronomannan Oligosaccharides in an MPTP-Induced Parkinson's Model.

Parkinson's disease (PD), characterized by dopaminergic neuron degeneration in the substantia nigra and dopamine depletion in the striatum, affects up to 1% of the global population over 50 years of age. Our previous study found that a heteropolysaccharide from Saccharina japonica exhibits neuroprotective effects through antioxidative stress. In view of its high molecular weight and complex structure, we degraded the polysaccharide and subsequently obtained four oligosaccharides. In this study, we aimed to further detect the neuroprotective mechanism of the oligosaccharides. We applied MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) to induce PD, and glucuronomannan oligosaccharides (GMn) was subsequently administered. Results showed that GMn ameliorated behavioral deficits in Parkinsonism mice. Furthermore, we observed that glucuronomannan oligosaccharides contributed to down-regulating the apoptotic signaling pathway through enhancing the expression of tyrosine hydroxylase (TH) in dopaminergic neurons. These results suggest that glucuronomannan oligosaccharides protect dopaminergic neurons from apoptosis in PD mice.

Isolations, characterizations and bioactivities of polysaccharides from the seeds of three species Glycyrrhiza.

In this paper, polysaccharides from the seeds of three species of genus Glycyrrhiza were extracted to investigate the physicochemical properties, structural characteristics and antioxidant activities. The polysaccharides were composed of xylose, mannose, galactose, and glucose with different molar ratio. Fourier transform infrared spectroscopy showed the presence of key functional groups of polysaccharides whereas scanning electron microscopy analysis revealed the characteristic morphology of different polysaccharides, and thermogravimetric analysis exhibited good thermal stability of all samples. The antioxidant activities of polysaccharides were evaluated in vitro. All the three polysaccharides demonstrated strong reducing power, as well as scavenging activity against DPPH, ABTS, and hydroxyl free radicals. Antioxidant assays indicated that all the polysaccharides have obvious antioxidant activities and possess a potential development and application value in food, cosmetics as well as pharmaceutical industries.

Salivary N-glycosylation as a biomarker of oral cancer: A pilot study.

Reliable biomarkers for oral cancer (OC) remain scarce, and routine tests for the detection of precancerous lesions are not routine in the clinical setting. This study addresses a current unmet need for more sensitive and quantitative tools for the management of OC. Whole saliva was used to identify and characterize the nature of glycans present in saliva and determine their potential as OC biomarkers. Proteins obtained from whole saliva were subjected to PNGase F enzymatic digestion. The resulting N-glycans were analyzed with weak anion exchange chromatography, exoglycosidase digestions coupled to ultra-high performance liquid chromatography and/or mass spectrometry. To determine N-glycan changes, 23 individuals with or without cancerous oral lesions were analyzed using Hydrophilic interaction ultra performance liquid chromatography (HILIC-UPLC), and peak-based area relative quantitation was performed. An abundant and complex salivary N-glycomic profile was identified. The main structures present in saliva were neutral oligosaccharides consisting of high mannose, hybrid and complex structures, followed by smaller fractions of mono and di-sialylated structures. To determine if differential N-glycosylation patterns distinguish between OC and control groups, Mann-Whitney testing and principle component analysis (PCA) were used. Eleven peaks were shown to be statistically significant (P ≤ 0.05), while PCA analysis showed segregation of the two groups based on their glycan profile. N-glycosylation changes are active in the oral carcinogenic process and may serve as biomarkers for early detection to reduce morbidity and mortality. Identifying which N-glycans contribute most in the carcinogenic process may lead to their use in the detection, prognosis and treatment of OC.

A Unique Sugar l-Perosamine (4-Amino-4,6-dideoxy-l-mannose) Is a Compound Building Two O-Chain Polysaccharides in the Lipopolysaccharide of Aeromonas hydrophila Strain JCM 3968, Serogroup O6.

Lipopolysaccharide (LPS) is the major glycolipid and virulence factor of Gram-negative bacteria, including Aeromonas spp. The O-specific polysaccharide (O-PS, O-chain, O-antigen), i.e., the surface-exposed part of LPS, which is a hetero- or homopolysaccharide, determines the serospecificity of bacterial strains. Here, chemical analyses, mass spectrometry, and 1H and 13C NMR spectroscopy techniques were employed to study the O-PS of Aeromonas hydrophila strain JCM 3968, serogroup O6. MALDI-TOF mass spectrometry revealed that the LPS of A. hydrophila JCM 3968 has a hexaacylated lipid A with conserved architecture of the backbone and a core oligosaccharide composed of Hep6Hex1HexN1HexNAc1Kdo1P1. To liberate the O-antigen, LPS was subjected to mild acid hydrolysis followed by gel-permeation-chromatography and revealed two O-polysaccharides that were found to contain a unique sugar 4-amino-4,6-dideoxy-l-mannose (N-acetyl-l-perosamine, l-Rhap4NAc), which may further determine the specificity of the serogroup. The first O-polysaccharide (O-PS1) was built up of trisaccharide repeating units composed of one α-d-GalpNAc and two α-l-Rhap4NAc residues, whereas the other one, O-PS2, is an α1→2 linked homopolymer of l-Rhap4NAc. The following structures of the O-polysaccharides were established: O-PS1 →3)-α-l-Rhap4NAc-(1→4)-α-d-GalpNAc-(1→3)-α-l-Rhap4NAc-(1→ O-PS2 →2)-α-l-Rhap4NAc-(1→ The present paper is the first work that reveals the occurrence of perosamine in the l-configuration as a component of bacterial O-chain polysaccharides.

Exploring potential new galactomannan source of Retama reatam seeds for food, cosmetic and pharmaceuticals: Characterization and physical, emulsifying and antidiabetic properties.

In this study, physicochemical, interfacial and emulsifying properties of Retama reatam and guar galactomannans were comparatively investigated. The results showed that Retama reatam galactomannan is mainly composed of total carbohydrates (95.52%) and lower protein contents (0.87%). The sugars identified were mannose (Man) and galactose (Gal), with a Man:Gal ratio of 1.85 compared to guar gum (1.83). The results of thermal properties indicated were transition temperature (Tg) and melting temperature (Tm) very similar to those of the guar gum. Moreover, results also revealed that there is no significant difference in terms of equilibrium interfacial tension of Retama reatam gum at 10 and 20°C. Moreover, preliminary tests show that stable oil-in-water nanoemulsions may be formulated using Retama reatam gum. Therefore, measurement of mean oil droplet diameter d after heating at 80°C, shows that stable nanoemulsions may be formulated using Retama reatam galactomannan. Further in vivo experiments confirmed that Retama reatam gum can reduce the glycemic index of starchy foods and inhibit the surge of postprandial blood glucose level.

Structure and gene cluster of the O antigen of Escherichia coli F17, a candidate for a new O-serogroup.

Escherichia coli F17 isolated from horse feces was studied in respect to the O antigen (O polysaccharide) structure and genetics. The lipopolysaccharide was isolated by phenol-water extraction of bacterial cells and cleaved by mild acid hydrolysis to yield the O polysaccharide, which was studied by sugar analysis and selective solvolysis with CF3CO2H along with one- and two-dimensional 1H and 13C NMR spectroscopy. The O polysaccharide was found to have a branched pentasaccharide repeat (O-unit) containing one residue each of d-galactose, d-mannose, l-rhamnose, d-glucuronic acid, and N-acetyl-d-glucosamine; about 2/3 units bear a side-chain glucose residue. To our knowledge, the F17 O-polysaccharide structure established is unique among known bacterial polysaccharide structures. The O-antigen gene cluster of E. coli F17 between the conserved genes galF and gnd was sequenced and found to be 99% identical to that of E. coli 102,755 assigned to a novel OgN8 genotype (A. Iguchi, S. Iyoda, K. Seto, H. Nishii, M. Ohnishi, H. Mekata, Y. Ogura, T. Hayashi, Front. Microbiol. 7 (2016) 765). Genes in the cluster were annotated taking into account the F17 O-polysaccharide structure. The data obtained confirm that E. coli F17 and E. coli strains belonging to the OgN8 genotype can be considered as a candidate to a new E. coli O-serogroup. The O antigen of this novel type was demonstrated to make for an effective shield protecting the intimate outer membrane surface of bacteria from direct interaction with bacteriophages.

Physicochemical Characterization, Antioxidant and Immunostimulatory Activities of Sulfated Polysaccharides Extracted from Ascophyllum nodosum.

Polysaccharides from Ascophyllum nodosum (AnPS) were extracted and purified via an optimized protocol. The optimal extraction conditions were as follows: extraction time of 4.3 h, extraction temperature of 84 °C and ratio (v/w, mL/g) of extraction solvent (water) to raw material of 27. The resulting yield was 9.15 ± 0.23% of crude AnPS. Two fractions, named AnP1-1 and AnP2-1 with molecular weights of 165.92 KDa and 370.68 KDa, were separated from the crude AnPS by chromatography in DEAE Sepharose Fast Flow and Sephacryl S-300, respectively. AnP1-1 was composed of mannose, ribose, glucuronic acid, glucose and fucose, and AnP2-1 was composed of mannose, glucuronic acid, galactose and fucose. AnPS, AnP1-1 and AnP2-1 exhibited high scavenging activities against ABTS radical and superoxide radical, and showed protective effect on H2O2-induced oxidative injury in RAW264.7 cells. Furthermore, the immunostimulatory activities of AnP1-1 and AnP2-1 were evaluated by Caco-2 cells, the results showed both AnP1-1 and AnP2-1 could significantly promote the production of immune reactive molecules such as interleukin (IL)-8, IL-1ß, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α. Therefore, the results suggest that AnPS and its two fractions may be explored as a potential functional food supplement.

Extraction, characterisation and antioxidant activity of polysaccharides from Chinese watermelon.

Extraction and antioxidant activity of polysaccharides from the Chinese watermelon was investigated. The polysaccharides were obtained by hot water extraction, ethanol precipitation, and deproteinization with HCl, respectively. The molecular weight was 3.02 × 104. It showed by high performance liquid chromatography (HPLC) and TLC that Chinese watermelon polysaccharides consisted of six monosaccharides, namely glucose, galactose, mannose, xylose, arabinose, and rhamnose. The polysaccharides contained the ß-glycosidic bond. Moreover, it was proved that the polysaccharides had high scavenging ability to superoxide anions.

Isolation of sophorose during sophorolipid production and studies of its stability in aqueous alkali: epimerisation of sophorose to 2-O-ß-D-glucopyranosyl-D-mannose.

NMR and anion exchange chromatography analysis of the waste streams generated during the commercial production of sophorolipids by the yeast Candida bombicola identified the presence of small but significant quantities (1% w/v) of free sophorose. Sophorose, a valuable disaccharide, was isolated from the aqueous wastes using a simple extraction procedure and was purified by chromatography on a carbon celite column providing easy access to large quantities of the disaccharide. Experiments were undertaken to identify the origin of sophorose and it is likely that acetylated sophorose derivatives were produced by an enzyme catalysed hydrolysis of the glucosyl-lipid bond of sophorolipids; the acetylated sophorose derivatives then undergo hydrolysis to release the parent disaccharide. Treatment of sophorose with aqueous alkali at elevated temperatures (0.1M NaOH at 50 °C) resulted in C2-epimerisation of the terminal reducing sugar and its conversion to the corresponding 2-O-ß-D-glucopyranosyl-D-mannose which was isolated and characterised. In aqueous alkaline solution ß-(1,2)-linked glycosidic bonds do not undergo either hydrolysis or peeling reactions.

O-Glycan analysis of cellobiohydrolase I from Neurospora crassa.

We describe here the composition of the O-linked glycans on the Neurospora crassa cellobiohydrolase I (CBHI), which accounts for approximately 40% of the protein secreted by cells growing in the presence of cellulose. CBHI is O-glycosylated with six types of linear, and three types of branched, O-glycans containing approximately equal amounts of mannose and galactose. In addition to the classic fungal O-glycans with reducing end mannoses, we also identified reducing end galactoses which suggest the existence of a protein-O-galactosyltransferase in N. crassa Because of the excellent genetic resources available for N. crassa, the knowledge of the CBHI O-glycans may enable the future evaluation of the role of O-glycosylation on cellulase function and the development of directed O-glycan/cellulase engineering.

Characterization and antioxidant activity in vitro and in vivo of polysaccharide purified from Rana chensinensis skin.

Preliminary characterization and antioxidant activity in vitro and in vivo investigation of the polysaccharide fraction named as RCSP II, which was extracted from Rana chensinensis skin, were performed. Results indicated that RCSP II comprised glucose, galactose, and mannose in a molar ratio of 87.82:2.77:1.54 with a molecular weight of 12.8 kDa. Antioxidant activity assay in vitro showed that RCSP II exhibited 75.2% scavenging activity against 2,2'-azino-bis(3-ethylbenz-thiazoline-6-sulfonic acid) radicals at the concentration of 2500 mg/L and 85.1% against chelated ferrous ion at 4000 mg/L. Antioxidant activity assay in vivo further showed that RCSP II increased the activities of antioxidant enzymes, decreased the levels of malondialodehyde, and enhanced total antioxidant capabilities in livers and sera of d-galactose induced mice. These results suggested that RCSP II could have potential antioxidant applications as medicine or functional food.

α-Glucosidase Inhibitors from a Xylaria feejeensis Associated with Hintonia latiflora.

Two new compounds, pestalotin 4'-O-methyl-ß-mannopyranoside (1) and 3S,4R-(+)-4-hydroxymellein (2), were isolated from an organic extract of a Xylaria feejeensis, which was isolated as an endophytic fungus from Hintonia latiflora. In addition, the known compounds 3S,4S-(+)-4-hydroxymellein (3), 3S-(+)-8-methoxymellein (4), and the quinone derivatives 2-hydroxy-5-methoxy-3-methylcyclohexa-2,5-diene-1,4-dione (5), 4S,5S,6S-4-hydroxy-3-methoxy-5-methyl-5,6-epoxycyclohex-2-en-1-one (6), and 4R,5R-dihydroxy-3-methoxy-5-methylcyclohexen-2-en-1-one (7) were obtained. The structures of 1 and 2 were elucidated using a set of spectroscopic and spectrometric techniques. The absolute configuration of the stereogenic centers of 1 and 2 was determined using ECD spectroscopy combined with time-dependent density functional theory calculations. In the case of 1, comparison of the experimental and theoretical (3)J6-7 coupling constants provided further evidence for the stereochemical assignments. Compounds 2 and 3 inhibited Saccharomyces cerevisiae α-glucosidase (αGHY), with IC50 values of 441 ± 23 and 549 ± 2.5 µM, respectively. Their activity was comparable to that of acarbose (IC50 = 545 ± 19 µM), used as positive control. Molecular docking predicted that both compounds bind to αGHY in a site different from the catalytic domain, which could imply an allosteric type of inhibition.

Extraction optimization, preliminary characterization and immunological activity of polysaccharides from figs.

Complex enzyme extraction (CEE), purification, characterization of fig polysaccharides (FPs) from dried figs were investigated. Orthogonal experiment was used to optimize the concentration of cellulose, pectinase and papain. Response surface methodology (RSM) was employed to optimize extraction conditions. The optimum extraction conditions were: enzyme concentration of 1.5%, 1.5%, 0.5% (wt%) of pectinase, papain, cellulose, ratio of water to raw material 40.3 mL/g, extraction time 54.1 min, temperature 34.15 °C and pH 3.8. Under these conditions, the experimental yield was 7.98 ± 0.17%. Two homogeneous heteropolysaccharides (FPs-1-1, FPs-2-1) were purified by DEAE-Sepharose and Sephadex G-200 chromatography, which were composed of rhamnose, arabinose, xylose, mannose, glucose and galactose with molecular weight of 1.52 × 10(6) and 4.75 × 10(5)Da, respectively. The bioactivity assay showed that FPs-1-1 and FPs-2-1 could more significantly enhance splenic lymphocyte proliferation, phagocytosis and NO production of macrophages, could be explored as potential immunopotentiating agent for use in functional food or medicine.

Optimization of alkaline extraction and bioactivities of polysaccharides from rhizome of Polygonatum odoratum.

The present study is to explore the optimal extraction parameters, antioxidant activity, and antimicrobial activity of alkaline soluble polysaccharides from rhizome of Polygonatum odoratum. The optimal extraction parameters were determined as the following: NaOH concentration (A) 0.3 M, temperature (B) 80 °C, ratio of NaOH to solid (C) 10-fold, and extraction time (D) 4 h, in which ratio of NaOH to solid was a key factor. The order of the factors was ratio of NaOH to solid (fold, C) > extraction temperature (°C, B) > NaOH concentration (M, A) > extraction time (h, D). The monosaccharide compositions of polysaccharides from P. odoratum were rhamnose, mannose, xylose, and arabinose with the molecular ratio of 31.78, 31.89, 11.11, and 1.00, respectively. The reducing power, the 1, 1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging rate, the hydroxyl radicals scavenging rate, and the inhibition rate to polyunsaturated fatty acid (PUFA) peroxidation of the alkaline soluble polysaccharides from P. odoratum at 1 mg/mL were 9.81%, 52.84%, 19.22%, and 19.42% of ascorbic acid at the same concentration, respectively. They also showed antimicrobial activity against pathogenic bacteria Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, and Escherichia coli.

Structural elucidation of the exopolysaccharide produced by the mangrove fungus Penicillium solitum.

A water soluble extracellular polysaccharide, designated GW-12, was obtained from the liquid culture broth of the mangrove fungus Penicillium solitum by ethanol precipitation, anion-exchange and size-exclusion chromatography. Reversed-phase high performance liquid chromatography analysis showed that GW-12 mainly consisted of d-mannose, and its molecular weight was estimated to be about 11.3 kDa determined by high performance gel permeation chromatography. On the basis of chemical and spectroscopic analyses, including methylation analysis and nuclear magnetic resonance (NMR) spectroscopy, the structure of GW-12 may be represented as a mannan with branches. The main chain of GW-12 was composed of (1 → 2)-linked α-D-mannopyranose and (1 → 6)-linked α-D-mannopyranose residues, branched by single α-d-mannopyranose units attached to the main chain at C-6 positions of (1 → 2)-linked α-D-mannopyranose residues. There was three branch points for every seven sugar residues in the backbone.