Glucopyranose Residues Research Articles

Structural Analysis and Antioxidant Activity of Alkaline-Extracted Glucans from Hericium erinaceus.

An alkali-soluble β-glucan (AHEP-A-b, 20 kDa) purified from Hericium erinaceus fruiting bodies, was structurally characterized and examined for antioxidant activity. Methylation analysis and NMR spectroscopy show that the backbone of AHEP-A-b is composed of (1→6)-linked-D-β-glucopyran residues, branched at O-3 of glucopyranose (Glcp) residues with [→3)-β-D-Glcp-(1→] oligosaccharides or single unit of β-Glcp. Periodate oxidation analysis and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) indicate that the degree of polymerization (DP) of [→3)-β-D-Glcp-(1→] side chains is 2 to 8. Functionally, AHEP-A-b is a relatively strong antioxidant as demonstrated by using 2, 2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) free radical (ABTS·+), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, and hydroxyl radicals scavenging assays. The present study lays the foundation for further studies into structure-activity relationships of polysaccharides from H. erinaceus.

Limosilactobacillus fermentum strains MC1 and D12: Functional properties and exopolysaccharides characterization

Lactic acid bacteria (LAB) produce a broad spectrum of exopolysaccharides (EPSs), commonly used as texturizers in food products. Due to their potential contribution to LAB probiotic properties, like adhesion to human epithelial cells and competitive exclusion of pathogens from human intestinal epithelial cells, this study was focussed on the structural and functional characterization of the EPSs produced by two Limosilactobacillus fermentum strains – MC1, originating from mother's milk, and D12, autochthonous from Croatian smoked fresh cheese. Whole-genome sequencing and functional annotation of both L. fermentum strains by RAST server revealed the genes involved in EPS production and transport, with some differences in functionally related genes. EPSs were extracted from the cell surface of both bacterial strains and purified by size-exclusion chromatography. Structural characterization of the EPSs, achieved by chemical analyses and 1D and 2D NMR spectroscopy, showed that both strains produce an identical mixture of three different EPSs containing galactofuranose and glucopyranose residues. However, a comparison of the functional properties showed that the MC1 strain adhered better to the Caco-2 cell line and exhibited stronger antimicrobial effect against Salmonella enterica serovar Typhimurium FP1 than the D12 strain, which may be attributed to the potential bacteriocin activity of the MC1 strain.

Angelica gigas polysaccharide induces CR3-mediated macrophage activation and the cytotoxicity of natural killer cells against HCT-116 cells via NF-κB and MAPK signaling pathways

Angelica gigas (A. gigas) is traditional medicinal herb that mainly exists in Korea and northeastern China. There have been relatively few studies conducted thus far on its polysaccharides and their bioactivities. We purified and described a novel water-soluble polysaccharide derived from A. gigas and investigated its immunoenhancing properties. The basic components of crude and purified polysaccharides (F1 and F2) were total sugar (41.07% - 70.55%), protein (1.12–10.33%), sulfate (2.9–5.5%), and uronic acids (0.5–31.05%) in total content. Our results demonstrated that the crude and fractions' molecular weights (Mw) varied from 42.2 to 285.2 × 103 g/mol. As the most effective polysaccharide, F2 significantly stimulated RAW264.7 cells to release nitric oxide (NO) and express several cytokines. Furthermore, F2 increased the expression of tumor necrosis factor-α (TNF-α), interferon-gamma (IFN-ɣ), natural killer cytotoxicity receptors (NKp44), and granzyme-B in NK-92 cells and enhanced the cytotoxicity against HCT-116 cells. In our experiments, we found that F2 stimulated RAW264.7 cells and NK-92 cells via MAPK and NF-κB pathways. The monosaccharide and methylation analysis of the high immunostimulant F2 polysaccharide findings revealed that the polysaccharide was primarily composed of 1 → 4, 1 → 6, 1 → 3, 6, 1 → 3 and 1 → 3, 4, 6 galactopyranose residues, 1 → 3 arabinofuranose residues, 1 → 4 glucopyranose residues. These results demonstrated that the F2 polysaccharide of A. gigas which possesses potential immunostimulatory attributes, could be used to create a novel functional food.

Isolation and Physicochemical Characteristics of Water-Soluble Polysaccharide from Locally Growing and Cultivated Basidium Raw Materials of Ganoderma lucidum

Branched polysaccharides have been isolated from basidiomycete raw materials of locally growing and cultivated Ganoderma lucidum. It has been found that the isolated fractions contain branched polysaccharides in the form of complexes with melanin. After purification of polysaccharides by ion exchange chromatography from locally growing and cultivated basidial raw materials, two fractions have been obtained: neutral polysaccharides of locally growing Ganoderma lucidum (GW-1), cultivated Ganoderma lucidum (GWL-1) with a yield of 25.71 and 29.85%, respectively, and anionic polysaccharides of locally growing Ganoderma lucidum (GW-2), cultivated Ganoderma lucidum (GWL-2), with a yield of 5.26 and 4.19%. The physicochemical properties of the obtained samples have been studied by IR and UV spectroscopies. The purity degree of fractions of branched polysaccharides has been determined. Using gas chromatography, one-dimensional (13C NMR, 1H NMR), and two-dimensional (COSY, TOCSY, HSQC, HMBC, NOESY) NMR spectroscopies, the compositions and molecular structures of the obtained polysaccharide samples have been determined. The results showed that the isolated and purified polysaccharides are β-glucan-type branched polysaccharides that have branch point (1,4,6)- and (1,3,6)-linked glucopyranose residues.

Effects of extracted polysaccharides from a Chlorella vulgaris biomass on expression of interferon-γ and interleukin-2 in chicken peripheral blood mononuclear cells

Polysaccharides isolated from algae species have been shown to have various biological properties including immunomodulatory activities. In the present study, the effects of water-extractable polysaccharides from a Chlorella vulgaris biomass on the expression of immunostimulatory cytokines by chicken peripheral blood mononuclear cells (PBMCs) were evaluated. Extracted polysaccharides were fractionated using a DEAE Sepharose FF column yielding two fractions (F1 and F2). Crude polysaccharide (CP) and fractions mostly consisted of carbohydrates (71.9 to 82.9%), protein (6 to 13.8%), and uronic acids (4.8 to 7.9%). Monosaccharide constituents were predominantly galactose (13.1 to 53.2%), glucose (15.3 to 38.6%), mannose (5.5 to 11.2%), arabinose (5.6 to 20.7%), and rhamnose (5.8 to 14.7%). Crude, F1, and F2 polysaccharides contained 1 or 2 sub-fractions with average molecular weight ranging from 19.2 to 161.1 × 103 g mol−1. Evaluation of immunostimulatory activities of CP and fractions (200 to 1000 μg mL−1) revealed significant effects on PBMC interferon-γ (IFN-γ) and interleukin-2 (IL-2) expression. The most potent immunostimulating fraction F1 was consisted of a homogeneous polysaccharide with relatively low molecular weight (23.9 × 103 g mol−1), low structural compactness, and mixed linkages of (→1)-, (1→3)-, (1→3,6)-galactopyranose and -glucopyranose residues.

Preliminary Structural Characteristic of Polysaccharides Extracted From the Callus Tissue of Sosnowskyi’s Hogweed (Heracleum Sosnowskyi Manden) Stem by Aqueous Ammonium Oxalate

Pectic polysaccharides have been isolated from callus tissue of the stem of Sosnowskyi’s hogweed (Heracleum sosnowskyi Manden) by extraction with a 0.7% aqueous solution of ammonium oxalate and characterized. It was shown that they differ from pectic polysaccharides of a native plant by a lower content of D‑galacturonic acid residues and a higher content of arabinose and galactose residues. The results obtained by a combination of ion exchange chromatography, enzymatic hydrolysis, periodate oxidation, methylation and NMR spectroscopy indicated the presence of low-methyl esterified 1,4-α-D-galacturonan, rhamogalacturonan-I, arabinan and galactan or arabinogalactan. The terminal 1,2- and 1,5-linked arabinofuranose residues, terminal, 1,3-, 1,6-linked and 3,6-substituted galactopyranose residues and 1,4-linked hexopyranose (galactopyranose or glucopyranose) residues were identified in the composition of neutral carbohydrate chains. The presence in the NMR spectra of trans-glycosyl correlation peaks of the methyl groups of 2,4-di-O-substituted rhamnose residues indirectly confirm the attachment arabinan, galactan or arabinogalactan carbohydrate chains to rhamnopyranose residues of the backbone at C-4 position.

Substantiation of the mechanism of interaction between the carbohydrates of rye­wheat flour and nanoparticles of the polyfunctional food additive "Magnetofооd"

Moisture-retaining capacity (MRC) is one of the most important functional-technological properties. The food additive Magnetofood produces a comprehensive effect, including MRC. That explains the importance of studying the MRC mechanism of Magnetofood. We have established the mechanism of interaction between nanoparticles (NP) of the food additive Magnetofood and the functional groups of biopolymers of the carbohydrate complex of rye-wheat flour. A cluster-capillary MRC model of Magnetofood with dough carbohydrates is proposed. Water molecules are initially adsorbed, particularly at the surface of starch grains and in micro capillaries. The Magnetofood NP, due to their nano dimensions, active and ionized surface, biocompatibility with the polymeric molecules of carbohydrates, easily penetrate their pores (micro-capillaries). The Magnetofood NP possess a high chemical potential; they, consequently, activate, for example, the surface of starch grains and the inner surface of capillaries. The nanoparticles of Magnetofood form complexes with the ОН-groups and ether of oxygen of amylose and amylopectin of starch through coordination bonds. There emerge the supramolecular ensembles Magnetofood-carbohydrate of the cluster type. The Magnetofood NP electrostatically interact also with the dipoles of water. Strong aqua complexes thereby form. The Н2О molecules then penetrate the least organized sections of chains of polysaccharide macromolecules. They are retained there by the hydrogen bonds with the Magnetofood dipoles and the ionogenic groups of carbohydrates: atoms of hydrogen and oxygen of the ОН-groups of D- glucopyranose residues. Aqua complexes form around the Magnetofood NP; solvato associates form in the clusters. Polymer chain diverge thereby improving the penetration of Н2О dipoles inside the carbohydrate. Such water absorption weakens the intra-macro-molecular bonds in the dense layers of the polysaccharide and contributes to the penetration of moisture inside. We have experimentally determined that the food additive Magnetofood produces a comprehensive effect: sorption, complexing, moisture- and fat-retaining. That leads to an increase in yield and improves quality of bakery products. In this context, the research results are of interest not only for Ukraine but also for the scientific community in other countries.

Structural analysis of rebaudioside A derivatives obtained by Lactobacillus reuteri 180 glucansucrase-catalyzed trans-α-glucosylation

The wild-type Gtf180-ΔN glucansucrase enzyme from Lactobacillus reuteri 180 was found to catalyze the α-glucosylation of the steviol glycoside rebaudioside A, using sucrose as glucosyl donor in a transglucosylation process. Structural analysis of the formed products by MALDI-TOF mass spectrometry, methylation analysis and NMR spectroscopy showed that rebaudioside A is specifically α-d-glucosylated at the steviol C-19 β-d-glucosyl moiety (55% conversion). The main product is a mono-(α1 → 6)-glucosylated derivative (RebA-G1). A series of minor products, up to the incorporation of eight glucose residues, comprise elongations of RebA-G1 with mainly alternating (α1 → 3)- and (α1 → 6)-linked glucopyranose residues. These studies were carried out in the context of a program directed to the improvement of the taste of steviol glycosides via enzymatic modification of their naturally occurring carbohydrate moieties.

Structure, Properties and Medical Advances for Biocellulose Applications: A Review

Microbial exopolysaccharides (EPS) obtained from microbial sources, became simply available for a broad range of applications, especially for medicine and pharmaceutical industries. One of these EPS bacterial cellulose known as biocellulose (BC). BC is a pure extracellular cellulose, which accumulate outside the cells, produced by several species of microorganisms, like Gluconacetobacter; Achromobacter; Sarcina and Agrobacterium with a great number of applications. It is an organic unbranched polysaccharide, type β-1,4-glucan, composed of glucopyranose residues. Biocellulose is used as artificial skin and occlusive dressings to treat chronic wounds and to heal burns, in microsurgeries as artificial blood vessels, scaffolds in tissue engineering and many other applications. This work represents a review on this remarkably microbial biomaterial and thus an update of a collection of scientific data from original research between 1979 and 2016. The paper started on structural, composition, properties and characterization and biogenesis of this biopolymer, then it gives a synthesis on a variety of biomedical applications.

Cell Wall Glycopolymers of Type Strains from Three Species of the Genus Actinoplanes.

The structures of cell wall glycopolymers from the type strains of three Actinoplanes species were investigated using chemical methods, NMR spectroscopy, and mass spectrometry. Actinoplanes digitatis VKM Ac-649(T) contains two phosphate-containing glycopolymers: poly(diglycosyl-1-phosphate) →6)-α-D-GlcpNAc-(1-P-6)-α-D-GlcpN-(1→ and teichoic acid →1)-sn-Gro-(3-P-3)-β-[β-D-GlcpNAc-(1→2]-D-Galp-(1→. Two glycopolymers were identified in A. auranticolor VKM Ac-648(T) and A. cyaneus VKM Ac-1095(T): minor polymer- unsubstituted 2,3-poly(glycerol phosphate), widely abundant in actinobacteria (Ac-648(T)), and mannan with trisaccharide repeating unit →2)-α-D-Manp-(1→2)-α-D-Manp-(1→6)-α-D-Manp-(1→ (Ac-1095(T)). In addition, both microorganisms contain a teichuronic acid of unique structure containing a pentasaccharide repeating unit with two residues of glucopyranose and three residues of diaminouronic acids in D-manno- and/or D-gluco-configuration. Each of the strains demonstrates peculiarities in the structure of teichuronic acid with respect to the ratio of diaminouronic acids and availability and location of O-methyl groups in glucopyranose residues. All investigated strains contain a unique set of glycopolymers in their cell walls with structures not described earlier for prokaryotes.

Purification, Chemical Characterization, and Bioactivity of an Extracellular Polysaccharide Produced by the Marine Sponge Endogenous Fungus Alternaria sp. SP-32.

Marine sponges are ancient and simple multicellular filter-feeding invertebrates attached to solid substrates in benthic habitats and host a variety of fungi both inside and on their surface because of its unique ingestion and digest system. Investigation on marine sponge-associated fungi mainly focused on the small molecular metabolites, yet little attention had been paid to the extracellular polysaccharides. In this study, a homogeneous extracellular polysaccharide AS2-1 was obtained from the fermented broth of the marine sponge endogenous fungus Alternaria sp. SP-32 using ethanol precipitation, anion-exchange, and size-exclusion chromatography. Results of chemical and spectroscopic analyses showed that AS2-1 was composed of mannose, glucose, and galactose with a molar ratio of 1.00:0.67:0.35, and its molecular weight was 27.4kDa. AS2-1 consists of a mannan core and a galactoglucan chain. The mannan core is composed of (1→6)-α-Manp substituted at C-2 by (1→2)-α-Manp with different degrees of polymerization. The galactoglucan chain consists of (1→6)-α-Glcp residues with (1→6)-β-Galf residues attached to the last glucopyranose residue at C-6. (1→6)-β-Galf residues have additional branches at C-2 consisting of disaccharide units of (1→2)-β-Galf and (1→2)-α-Glcp residues. The glucopyranose residue of the galactoglucan chain is linked to the mannan core. AS2-1 possessed a high antioxidant activity as evaluated by scavenging of 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radicals in vitro. AS2-1 was also evaluated for cytotoxic activity on Hela, HL-60, and K562 cell lines by the MTT and SRB methods. The investigation demonstrated that AS2-1 was a novel extracellular polysaccharide with different characterization from extracellular polysaccharides produced by other marine microorganisms.

Diverse Roles of Heparan Sulfate and Heparin in Wound Repair.

Heparan sulfate (HS) and heparin (Hp) are linear polysaccharide chains composed of repeating (1→4) linked pyrosulfuric acid and 2-amino-2-deoxy glucopyranose (glucosamine) residue. Mentioned glycosaminoglycans chains are covalently O-linked to serine residues within the core proteins creating heparan sulfate/heparin proteoglycans (HSPG). The latter ones participate in many physiological and pathological phenomena impacting both the plethora of ligands such as cytokines, growth factors, and adhesion molecules and the variety of the ECM constituents. Moreover, HS/Hp determine the effective wound healing process. Initial growth of HS and Hp amount is pivotal during the early phase of tissue repair; however heparan sulfate and heparin also participate in further stages of tissue regeneration.

Structural characterization and antioxidant activity of a heteropolysaccharide isolated from Hedysarum polybotrys

A water-soluble polysaccharide (HPS3aS) with a molecular mass of 1.22 × 104 Da was isolated from Hedysarum polybotrys using anion-exchange and gel-permeation chromatography. HPS3aS exhibits a globular-shaped conformation in 0.1 M NaNO3 by size exclusion chromatography with multi-angle laser light scattering (SEC-MALLS). The investigation of the structural features of this heteropolysaccharide through a combination of chemical and instrumental analyses revealed that the backbone of HPS3aS is composed of α-d-(1 → 4)-linked glucopyranose residues, which occasionally branched at O-6. The branches are composed of (1 → 4)-linked galactopyranose residues and terminated with glucopyranose residues. HPS3aS possesses good in vitro antioxidant activity, as evaluated by scavenging assays with 1,1-diphenyl-2-picrylhydrazyl, hydroxyl, and superoxide radicals, which suggests that HPS3aS could be a potential antioxidant.

Pectic polysaccharides in the stem calli of the rowan tree Sorbus aucuparia L

The water-soluble polysaccharide fractions SAcI and SAclI were isolated from rowan tree stem calli. The SAcI fraction was shown to contain compounds belonging to the arabinogalactan II group. The SAcII fraction, termed sorban, was found to contain pectic polysaccharides that make up the protopectin complex of the cell wall callusand that had a high content of galacturonic acid residues together with neutral sugars characteristic of rhamnogalacturonan I (RG-I) polysaccharides. Using methylation assays, some structural features of the ramified region of sorban were elucidated. The backbone of sorban was found to consist of 1,4-α-D-galacto-pyranosyluronic acid residues. The neutral sugars are represented by 1,6-linked galactopyranose and 1,5-linked arabinofuranose residues as the primary constituents, as well as 1,6-linked mannopyranose and 1,4-linked glucopyranose and xylopyranose residues. Callus growth was shown to be accompanied by nearly constant quantities of galacturonic acid and neutral sugar residues in sorban (fraction SAcII) from the rowan stem callus.

Disaccharide 1-phosphate polymers of some representatives of the Bacillus subtilis group

Disaccharide 1-phosphate polymers as well as teichoic acids of various structures have been found in the cell walls of the representatives of the Bacillus subtilis group, namely Bacillus subtilis subsp. spizizenii VKM B-720 and VKM B-916, B. subtilis VKM B-517, and Bacillus vallismortis VKM B-2653(T). Disaccharide 1-phosphate polymers are composed of repeating units of the following structure: -P-4)-β-D-GlcpNAc-(1→6)-α-D-Galp-(1-, the N-acetylglucosamine residues are partially acetylated at positions O3 and O6 (VKM B-720 and VKM B-916); -P-4)-β-D-Glcp-(1→6)-α-D-GlcpNAc-(1-, the glucopyranose residues are partially acetylated at positions O2 or O3 (VKM B-517); -P-6)-α-D-GlcpNH3(+)/α-D-GlcpNAc-(1→2)-α-D-Glcp-(1-, the N-acetylglucosamine residues are partially deacetylated (VKM B-2653(T)). The structures of the two last disaccharide 1-phosphate polymers have not been reported so far for Gram-positive bacteria. The teichoic acids in the studied strains are O-D-alanyl-1,5-poly(ribitol phosphates) substituted with β-D-glucopyranose (VKM B-517, VKM B-720, VKM B-916) or 2-acetamido-2-deoxy-β-D-glucopyranose (VKM B-2653(T)). The structures of the phosphate-containing polymers have been studied by chemical methods and by NMR spectroscopy.

A novel teichuronic acid, the major polymer from the cell wall of Actinoplanes lobatus VKM Ac-676T

The cell wall of Actinoplanes lobatus VKM Ac-676T (family Micromonosporaceae; order Actinomycetales; class Actinobacteria) contains two anionic glycopolymers. The major one is a teichuronic acid with a linear structure of the chain and heterogeneous repeating units, consisting of glucopyranose residues and statistically alternating residues of diaminouronic acids having the d-manno,l-gulo and d-gluco configurations in a ratio of 6:3:1, respectively. The teichuronic acid of this structure has not hitherto been found in Gram-positive bacteria. The minor glycopolymer is a teichoic acid of poly(glycosylpolyol phosphate) nature with the repeating unit -6)-[α-d-Manp(1→4)]-β-d-Galp-(1→2)-snGro-(3-P-. The structures of the glycopolymers were established by chemical methods and NMR spectroscopy.

Mild and Efficient Strategy for Site-Selective Aldehyde Modification of Glycosaminoglycans: Tailoring Hydrogels with Tunable Release of Growth Factor

Aldehydes have been used as an important bioorthogonal chemical reporter for conjugation of large polymers and bioactive substances. However, generating aldehyde functionality on carbohydrate-based biopolymers without changing its native chemical structure has always persisted as a challenging task. The common methods employed to achieve this require harsh reaction conditions, which often compromise the structural integrity and biological function of these sensitive molecules. Here we report a mild and simple method to graft aldehydes groups on glycosaminoglycans (GAGs) in a site-selective manner without compromising the structural integrity of the biopolymer. This regio-selective modification was achieved by conjugating the amino-glycerol moiety on the carboxylate residue of the polymer, which allowed selective cleavage of pendent diol groups without interfering with the C2-C3 diol groups of the native glucopyranose residue. Kinetic evaluation of this reaction demonstrated significant differences in second-order reaction rate for periodate oxidation (by four-orders of magnitude) between the two types of vicinal diols. We employed this chemistry to develop aldehyde modifications of sulfated and nonsulfated GAGs such as hyaluronic acid (HA), heparin (HP), and chondroitin sulfate (CS). We further utilized these aldehyde grafted GAGs to tailor extracellular matrix mimetic injectable hydrogels and evaluated its rheological properties. The composition of the hydrogels was also found to modulate release of therapeutic protein such as FGF-2, demonstrating controlled release (60%) for over 14 days. In short, our result clearly demonstrates a versatile strategy to graft aldehyde groups on sensitive biopolymers under mild conditions that could be applied for various bioconjugation and biomedical applications such as drug delivery and regenerative medicine.

Pectin polysaccharides of rowan Sorbus aucuparia L.

Water-soluble polysaccharide fractions were extracted from the fruit of rowan Sorbus aucuparia L. by water and 0.7% ammonium oxalate water solution. The total yield was 4.2%. It is demonstrated that these fractions are pectin polysaccharides, and their carbon chains are primarily composed of galactunoric acid residue (up to 68%), arabinose and galactose. Sephacryl S-500 gelfiltration of rowan fruit pectin polysaccharides proved their relative homogeneity pertaining to their molecular weights, whereas endo-polygalacturonase enzymatic hydrolysis gives evidence of the presence of extended galacturonan (rhamnogalacturonan) ranges in their carbohydrate chains. Methylation of rowan pectin polysaccharides shows that their carbohydrate pendants are formed by 1,5-linked arabinofuranose residue, 1,4-linked glucopyranose residue, 1,6-linked galactopyranose residue, 1,3,6-linked mannopyranose residue and 1,3,6-linked galactopyranose residue. Glucopyranose residue is identified at non reducible ends of these pendants. It was demonstrated that antioxidant activity of water solutions of pectin polysaccharides extracted from rowan S. aucuparia L. (0.5 mg/mL) is 37–53% of trolox activity, which is 100%.

ChemInform Abstract: The Pyrolytic Behavior of Cellulose in Lignocellulosic Biomass: A Review

AbstractReview: 115 refs.

Branched glucan from the fruiting bodies of Piptoporus betulinus (Bull.:Fr) Karst.

A new glucan, namely, piptoporane I, with a molecular mass of 270 kDa was isolated from fruiting bodies of Piptoporus betulinis (Bull.:Fr.) Karst. (Fomitopsidacaeae). Using a combination ofphysicochemical methods, it was established that piptoporane I was a branched glucan with a backbone consisting of alpha-( 1->3)-glucopyranose residues substituted at the C-6 position by single residues of beta-D-glucopyranose by 17.3%. A polysaccharide with such a structure was isolated for the first time from the fungus genus Piptoporus.