Monosaccharide Residues Research Articles

Triterpene and Steroid Glycosides from Marine Sponges (Porifera, Demospongiae): Structures, Taxonomical Distribution, Biological Activities.

The article is a comprehensive review concerning tetracyclic triterpene and steroid glycosides from sponges (Porifera, Demospongiae). The extensive oxidative transformations of the aglycone and the use of various monosaccharide residues, with up to six possible, are responsible for the significant structural diversity observed in sponge saponins. The saponins are specific for different genera and species but their taxonomic distribution seems to be mosaic in different orders of Demospongiae. Many of the glycosides are membranolytics and possess cytotoxic activity that may be a cause of their anti-predatory activities. All these data reveal the independent origin and parallel evolution of the glycosides in different taxa of the sponges. The information concerning chemical structures, biological activities, biological role, and taxonomic distribution of the sponge glycosides is discussed.

Chilensosides E, F, and G—New Tetrasulfated Triterpene Glycosides from the Sea Cucumber Paracaudina chilensis (Caudinidae, Molpadida): Structures, Activity, and Biogenesis

Three new tetrasulfated triterpene glycosides, chilensosides E (1), F (2), and G (3), have been isolated from the Far-Eastern sea cucumber Paracaudina chilensis (Caudinidae, Molpadida). The structures were established based on extensive analysis of 1D and 2D NMR spectra and confirmed by HR-ESI-MS data. The compounds differ in their carbohydrate chains, namely in the number of monosaccharide residues (five or six) and in the positions of sulfate groups. Chilensosides E (1) and F (2) are tetrasulfated pentaosides with the position of one of the sulfate groups at C-3 Glc3, and chilensoside G (3) is a tetrasulfated hexaoside. The biogenetic analysis of the glycosides of P. chilensis has revealed that the structures form a network due to the attachment of sulfate groups to almost all possible positions. The upper semi-chain is sulfated earlier in the biosynthetic process than the lower one. Noticeably, the presence of a sulfate group at C-3 Glc3-a terminal monosaccharide residue in the bottom semi-chain of compounds 1 and 2-excludes the possibility of this sugar chain's further elongation. Presumably, the processes of glycosylation and sulfation are concurrent biosynthetic stages. They can be shifted in time in relation to each other, which is a characteristic feature of the mosaic type of biosynthesis. The hemolytic action of compounds 1-3 against human erythrocytes and cytotoxic activities against five human cancer cell lines were tested. The compounds showed moderate hemolytic activity but were inactive against cancer cells, probably because of their structural peculiarities, such as the combination of positions of four sulfate groups.

New Ceramides and Cerebrosides from the Deep-Sea Far Eastern Starfish Ceramaster patagonicus.

Three new ceramides (1–3) and three new cerebrosides (4, 8, and 9), along with three previously known cerebrosides (ophidiocerebrosides C (5), D (6), and CE-3-2 (7)), were isolated from a deep-sea starfish species, the orange cookie starfish Ceramaster patagonicus. The structures of 1−4, 8, and 9 were determined by the NMR and ESIMS techniques and also through chemical transformations. Ceramides 1–3 contain iso-C21 or C23 Δ9-phytosphingosine as a long-chain base and have C16 or C17 (2R)-2-hydroxy-fatty acids of the normal type. Cerebroside 4 contains C22 Δ9-sphingosine anteiso-type as a long-chain base and (2R)-2-hydroxyheptadecanoic acid of the normal type, while compounds 8 and 9 contain saturated C-17 phytosphingosine anteiso-type as a long-chain base and differ from each other in the length of the polymethylene chain of (2R)-2-hydroxy-fatty acids of the normal type: C23 in 8 and C24 in 9. All the new cerebrosides (4, 8, and 9) have β-D-glucopyranose as a monosaccharide residue. The composition of neutral sphingolipids from C. patagonicus was described for the first time. The investigated compounds 1–3, 5–7, and 9 exhibit slight to moderate cytotoxic activity against human cancer cells (HT-29, SK-MEL-28, and MDA-MB-231) and normal embryonic kidney cells HEK293. Compounds 2, 5, and 6 at a concentration of 20 µM inhibit colony formation of MDA-MB-231 cells by 68%, 54%, and 68%, respectively. The colony-inhibiting activity of compounds 2, 5, and 6 is comparable to the effect of doxorubicin, which reduces the number of colonies by 70% at the same concentration.

Mucin O-glycosylation and pathogen binding ability differ between rainbow trout epithelial sites

Mucins are highly glycosylated proteins that make up the mucus covering internal and external surfaces of fish. Mucin O-glycans regulate pathogen quorum sensing, growth, virulence and attachment to the host. Knowledge on this mucosal defense system can enable alternative treatments to diseases posing a threat to productivity and welfare in aquaculture. Here, we characterize the rainbow trout (Oncorhynchus mykiss) gill, skin, pyloric ceca and distal intestinal mucin O-glycosylation and compare it to known teleost O-glycomes. We identified 54 O-glycans, consisting of up to nine monosaccharide residues. Skin glycans were most acidic, shortest on average and consisted mainly of NeuAcα2-6GalNAc. Glycans from the gills were less acidic with predominantly core 1 and 2 glycans, whereas glycans from pyloric ceca and distal intestine expressed an increased number of core 5 glycans, distinctly decorated with NeuAcα2-8NeuAc- like epitopes. When compared to Atlantic salmon and Arctic charr, trends on the core distribution, average size and overall acidity remained similar, although the epitopes varied. Rainbow trout mucins from gill and intestine bound A. salmonicida and A. hydrophila more efficiently than skin mucins. This is in line with a model where skin mucins with small glycans limit bacterial adhesion to the fish surface whereas the complex intestinal mucin glycans aid in trapping and removing pathogens from the epithelial surface.

Extraction, Characterization, and Structure of a Novel Heteropolysaccharide from Lepidium sativum and Its Effects on Wound Healing in Diabetic Rats.

The present study undertakes the extraction of a novel polysaccharide from Lepidium sativum (PLS) and the determination of its physicochemical composition and antioxidant properties, as well as its potential wound healing activity in alloxan-induced diabetic rats. This polysaccharide presented a lighter natural color, whose luminosity (L∗), red-green intensity (a∗), and blue-yellow intensity (b∗) were recorded at 63.26, 5.87, and 27.28, respectively. The PLS was structurally characterized by Fourier transform infrared (FT-IR) spectroscopy, UV spectrum, high performance liquid chromatography (HPLC), gas chromatography (GC), nuclear resonance magnetic (NMR), and high-pressure gel filtration chromatography. The FT-IR and UV spectra showed the characteristic band of polysaccharides. According to HPLC, the crude PLS is a heteropolysaccharide composed of glucose, xylose, and galactose. Results obtained by 1H NMR indicated that PLS consisted of three monosaccharide residues with α and β anomers. This novel polysaccharide had an average molecular weight of 98.51 kDa and displayed potential antioxidant activities determined through three different assays: scavenging activity against 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay, and reducing power. These results strongly support the beneficial effects of the PLS to accelerate wound healing in diabetic rats. Indeed, its application significantly increased wound contraction percentage (98 ± 1.11%) after 14 days of experiment. Furthermore, the histological assessment of the PLS-treated group demonstrated complete reepithelialized wounds by accelerating collagen synthesis. In general, the findings affirmed that PLS is efficient on wound closure in alloxan-induced diabetic rats.

Clinical and Diagnostic Significance of Sialic Acids Determination in Biological Material.

Sialic acids (SA) are neuraminic acid derivatives, located at the terminal position in the chains of monosaccharide residues of various glycoconjugates. SA play a dual role: they either mask recognition sites, or, on the contrary, represent biological targets that can be recognized by receptor proteins and serve as ligands. The desialylation/sialylation processes can be considered as a dynamic modification regulated by sialyltransferases and sialidases in response to external or internal stimuli. This review describes the structural and functional diversity and the potential use of SA fractions as biomarkers for various pathological conditions. Almost any extreme impact on the body and inflammatory processes are accompanied by an increase in the level of both total and free SA in the blood and tissues. Possible reasons for the increase of sialoglycoconjugate metabolism indicators in biological material include: (i) activation of the hepatocyte synthesis and secretion of various acute-phase proteins, many of which are sialoglycoproteins, (ii) impaired membrane integrity and destruction of body cells, (iii) high activity of sialidases (neurominidases) and sialyltransferases. Most acute and chronic liver diseases are characterized by the decrease in the total level of SA in the blood serum (because many plasma proteins are synthesized and glycosylated in hepatocytes). Aberrant sialylation results in changes of sialoglycoconjugate structure, its ability to perform biological functions and sialoglycoconjugate half-life. Glycosylation is the most common post-translational modification of proteins in the virus, which not only promotes the formation of specific conformation of viral proteins, but also modulates their interaction with receptors and affects host cell recognition, viral replication and infectivity. Serum total SA concentration increases in some benign and inflammatory conditions, which indicates a lack of specificity and limits their use for early detection and screening of neoplastic diseases. Clinical and diagnostic value of determining the sialoglycoconjugate metabolic indicators, including changes in the content of both SA fractions and specific proteins in various biological fluids and tissues, consists in establishing the causes and mechanisms of biochemical changes in the body in certain diseases. In combination with the measurement of existing markers, they can be used to improve diagnosis, staging and monitoring of therapeutic response in some pathological conditions where the need for specificity is less than for specific diagnostics.

Изучение процесса ферментативного гидролиза предобработанной биомассы мискантуса

Forests being mostly non-renewable, miscanthus seems to be a promising alternative energy resource. This study investigates the enzymatic hydrolysis of pretreated miscanthus biomass. The research featured Miscanthus sinensis Strictus biomass. The methods included raw material pretreatment, enzymatic hydrolysis, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF) of monosaccharide residues, and nuclear magnetic resonance (1H NMR) spectrometry of non-hydrolyzed lignin. A hammer mill with a particle size of 0.2–0.3 mm proved to be effective for preliminary mechanical processing of miscanthus. This type of treatment provided the maximal yield of carbohydrate-containing biomass (62.33 ± 1.87%). The optimal multi-enzyme composition included Cellulase Ultra obtained from Trichoderma reeseii, xylanase obtained from Thermomyces lanuginosus, and β-gluconase obtained from Myceliophtorafergusii. The fermentation temperature was 50 ± 1°C (72 ± 1 h). At these parameters, the conversion of holocellulose of miscanthus biomass was 96.0 ± 4.8%, and the yield of reducing substances was 97.00 ± 4.85%. The article introduces the optimal enzymatic hydrolysis parameters for pretreating Miscanthus sinensis Strictus biomass as a source of carbohydrate-containing substrates and describes their subsequent use for bacterial cellulose biosynthesis. The carbohydrate composition of hydrolysates included residual lignin, such polysaccharides as glucan and xylan, and various monosaccharides, namely arabinose, xylose, galactose, glucose, and uronic acids. Hydrolyzed miscanthus proved to be an effective renewable and environmentally friendly biodiesel.

Physicochemical Characteristics and Antidiabetic Properties of the Polysaccharides from Pseudostellaria heterophylla.

This study aimed to investigate the Pseudostellaria heterophylla polysaccharides (PF40) physicochemical and antidiabetic characteristics. The ultraviolet–visible (UV) spectra, Fourier transform infrared radiation (FT-IR) spectra, nuclear magnetic resonance (NMR) spectra, zeta potential, surface characteristics, and conformational and thermal stability properties of PF40 were characterized. X-ray diffraction (XRD) and scanning electron microscopy (SEM), combined with Congo red test, revealed that PF40 powder has mainly existed in amorphous form with triple-helix conformation. The single-molecular structure of PF40 exhibited a multi-branched structure extending from the center to the periphery by scanning probe microscopy (SPM) scanning. The monosaccharide residue of PF40 was an α-pyranoid ring and exhibits good stability below 168 °C. Experimental studies on antidiabetic characteristics found that PF40 could significantly improve STZ-induced intestinal mucosal damage and reduce the apoptosis of villus epithelial cells. PF40 combined with metformin could significantly improve the symptoms of insulin resistance in type 2 diabetes mellitus (T2DM) rats, the molecular mechanism might be through inhibiting the expression of RORγ protein and increasing Foxp3 protein in the jejunum of T2DM rats, and then restoring the STZ-induced imbalance of T helper 17(Th17)/ regulatory T cells (Treg) cells, thereby maintaining intestinal immune homeostasis. Results identified in this study provided important information regarding the structure and antidiabetic characteristics of Pseudostellaria heterophylla polysaccharides, which can contribute to the development of Pseudostellaria heterophylla polysaccharides for industrial purposes in the future.

Structural and bioactive characterization of purified polysaccharide from deep-freeze pretreated Sorghum bicolor L. leaf sheath

This study determined the effect of deep-freeze pretreatment of sorghum leaf sheath on the extraction yield of ultrasound-extracted purified polysaccharides (DFUP-1), and confirmed the physicochemical, structural and bioactive characteristics of DFUP-1. Deep-freeze pretreatment induced breaks in the cell walls and resulted in a higher yield (14.35%) of crude polysaccharide extract than without pretreatment (9.23%). The crude extract was purified using DEAE-52 cellulose ion exchange and Sephadex G-100 gel-filtration chromatography to obtain DFUP-1. The 1H and 13C NMR spectra of DFUP-1 showed the presence of β-glycosidic linkages and a substitution at C6 of the sugars which may be O-methyl substitution or due to β (1−6) linkages. Peaks for α-anomeric linkages were not detected. The FTIR spectrum of DFUP-1 confirmed its carbohydrate functional groups. Periodate oxidation and formic acid analysis of DFUP-1 showed 1-, 1–6, 1–2, 1–3 and 1–4 linkages. GC-MS analysis of monosaccharide residues of DFUP-1 showed presence of glucose, galactose, arabinose, mannose and xylose. Congo red assay showed that DFUP-1 was not of triple-helix configuration. The ABTS+ and DPPH radical scavenging assay showed an IC50 of 0.10 mg/mL and 1.19 mg/mL for DFUP-1 respectively. At 0.2 mg/mL DFUP-1 showed anti-inflammatory (anti-egg denaturation) activity of 41.52%. The DFUP-1 sample showed lower inhibitory effect against proliferation of leukemia cells at an IC50 of 37.43 µg/mL compared to curcumin with IC50 of 0.98 µg/mL. Taken together, deep-freeze pretreatment coupled with ultrasound extraction increases yield of sorghum leaf sheath polysaccharides with potential nutraceutical and pharmaceutical applications.

The Development of the Davis Food Glycopedia-A Glycan Encyclopedia of Food.

The molecular complexity of the carbohydrates consumed by humans has been deceptively oversimplified due to a lack of analytical methods that possess the throughput, sensitivity, and resolution required to provide quantitative structural information. However, such information is becoming an integral part of understanding how specific glycan structures impact health through their interaction with the gut microbiome and host physiology. This work presents a detailed catalogue of the glycans present in complementary foods commonly consumed by toddlers during weaning and foods commonly consumed by American adults. The monosaccharide compositions of over 800 foods from diverse food groups including Fruits, Vegetables, Grain Products, Beans, Peas, Other Legumes, Nuts, Seeds; Sugars, Sweets and Beverages; Animal Products, and more were obtained and used to construct the “Davis Food Glycopedia” (DFG), an open-access database that provides quantitative structural information on the carbohydrates in food. While many foods within the same group possessed similar compositions, hierarchical clustering analysis revealed similarities between different groups as well. Such a Glycopedia can be used to formulate diets rich in specific monosaccharide residues to provide a more targeted modulation of the gut microbiome, thereby opening the door for a new class of prophylactic or therapeutic diets.

Fragmentation analysis of O-specific polysaccharide from bacteria Vibrio cholerae O139 by MALDI-TOF and LC/ESI-MS/MS.

Cholera is a life-threatening diarrhoeal disease caused by ingestion of Vibrio cholerae. There are at least 200 serogroups of V. cholerae but only two of them are causing epidemics - O1 and O139 serogroups. Fragmentation analysis of O-antigen, also known as O-specific polysaccharide (OSP), from lipopolysaccharide (LPS) is important to obtain new information about its structure, such as fragmentation patterns and fragment structures. In the present study, OSP and core (OSPc) structure from V. cholerae O139 was studied using matrix-assisted laser desorption ionization (MALDI)-time of flight (TOF) and direct injection electrospray ionization (ESI)-MS methods. MALDI-TOF analysis was performed in positive-ion reflectron mode, while ESI-MS was performed in negative ionization mode. ESI-MS analysis was followed by ESI-MS/MS analysis. Using this analytical approach, we managed to obtain two possible fragmentation pathways of OSP from V. cholerae O139. Mutual sign of these two pathways is shortening the length of the oligosaccharide by neutral loss of monosaccharide residues. Additionally, liquid chromatography-MS analysis was performed to separate depicted molecular forms of OSPc.

Characterization, antioxidant and anticoagulant properties of exopolysaccharide from marine microalgae

The sulfated exopolysaccharide extracted from marine microalgae attracted considerable attention from both the nutraceutical and pharmaceutical industries. In the present study biomass of five marine microalgae were screened to find strains with high capacity for the production of sulfated exopolysaccharides. The anticoagulant and antioxidant activities of extracted sulfated polysaccharides were evaluated using activated partial thromboplastin time (aPTT), prothrombin time (PT), DPPH and ABTS assays, respectively. The sulfated polysaccharides extracted from Picochlorum sp. showed a strong DPPH scavenging effect with 85% antioxidant activity. The sulfated polysaccharides of Chlorella sorokiniana, Chlorella sp. (L2) and Chlorella sp. (D1) scavenged more than 90% of the ABTS radicals. However, the sulfated polysaccharide extracted from Chlorella sorokiniana, and Chlorella sp. (N4) showed anticoagulant properties. The dual anticoagulant-antioxidant activities in Chlorella sorokiniana could be explained by the combination of various factors including sulfate content and their binding site, monosaccharide residue and glycoside bond which are involved in the polysaccharide’s bioactivity.

The S-layer homology domains of Paenibacillus alvei surface protein SpaA bind to cell wall polysaccharide through the terminal monosaccharide residue

Self-assembling (glyco)protein surface layers (S-layers) are ubiquitous prokaryotic cell-surface structures involved in structural maintenance, nutrient diffusion, host adhesion, virulence, and other processes, which makes them appealing targets for therapeutics and biotechnological applications as biosensors or drug delivery systems. However, unlocking this potential requires expanding our understanding of S-layer properties, especially the details of surface-attachment. S-layers of Gram-positive bacteria often are attached through the interaction of S-layer homology (SLH) domain trimers with peptidoglycan-linked secondary cell wall polymers (SCWPs). Cocrystal structures of the SLH domain trimer from the Paenibacillus alvei S-layer protein SpaA (SpaASLH) with synthetic, terminal SCWP disaccharide and trisaccharide analogs, together with isothermal titration calorimetry binding analyses, reveal that while SpaASLH accommodates longer biologically relevant SCWP ligands within both its primary (G2) and secondary (G1) binding sites, the terminal pyruvylated ManNAc moiety serves as the nearly exclusive SCWP anchoring point. Binding is accompanied by displacement of a flexible loop adjacent to the receptor site that enhances the complementarity between protein and ligand, including electrostatic complementarity with the terminal pyruvate moiety. Remarkably, binding of the pyruvylated monosaccharide SCWP fragment alone is sufficient to cause rearrangement of the receptor-binding sites in a manner necessary to accommodate longer SCWP fragments. The observation of multiple conformations in longer oligosaccharides bound to the protein, together with the demonstrated functionality of two of the three SCWP receptor-binding sites, reveals how the SpaASLH-SCWP interaction has evolved to accommodate longer SCWP ligands and alleviate the strain inherent to bacterial S-layer adhesion during growth and division.

Clinical and diagnostic significance of sialic acids determination in biological material

Sialic acids (SA) are derivatives of neuraminic acid; they are located at the terminal position in the chains of monosaccharide residues of various glycoconjugates. SA play a dual role, they either mask recognition sites, or, on the contrary, represent biological targets that can be recognized by receptor proteins and serve as ligands. The desialylation/sialylation processes can be viewed as a dynamic modification regulated by sialyltransferases and sialidases in response to external or internal stimuli. This review describes the structural and functional diversity and the potential use of SA fractions as biomarkers for various pathological conditions. Almost any extreme effects on the body and inflammatory processes lead to an increase in the level of both total and free SA in the blood and tissues. Possible reasons for the increase of sialoglycoconjugate metabolism indicators in biological material include activation of the hepatocyte synthesis and secretion of various acute-phase proteins, many of which are sialoglycoproteins, violation of the membrane integrity and destruction of body cells, and also high activity of sialidases (neurominidases) and sialyltransferases. Most acute and chronic liver diseases are characterized by the decrease in the total level of SA in the blood serum (because many plasma proteins are synthesized and glycosylated in hepatocytes). Aberrant sialylation results in changes of sialoglycoconjugate structure, its ability to perform biological functions and half-life. Glycosylation is the most common post-translational modification of proteins in the virus, which not only promotes the formation of specific conformation of viral proteins, but also modulates their interaction with receptors and affects host cell recognition, viral replication and infectivity. Serum total SA concentration increases in some benign and inflammatory conditions, which indicates a lack of specificity and limits their use for early detection and screening of neoplastic diseases. Nevertheless, determining blood SA level and measuring concentration of existing biomarkers can be used to improve diagnostic indicators, to stage and monitor therapeutic response in some types of cancer, when the need for specificity is less than for diagnosis. Clinical and diagnostic value of determining the sialoglycoconjugate metabolic indicators, including changes in the content of both SA fractions and specific proteins in various biological fluids and tissues, lies in establishing the causes and mechanisms of biochemical changes in the body in certain diseases.

Hydrogelation from Scaled-Down Chitin Nanofibers by Reductive Amination of Monosaccharide Residues

Hydrogelation from Scaled-Down Chitin Nanofibers by Reductive Amination of Monosaccharide Residues

Structure characterization of an arabinogalactan from Cynanchum atratum and its immune stimulatory activity on RAW264.7 cells

In the present study, a water-soluble neutral polysaccharide (CAPW-1) with an average molecular weight of 64 kDa was purified from the root of Cynanchum atratum Bunge (Apocynaceae). The monosaccharide residue analysis revealed that CAPW-1 was composed of arabinose and galactose with a relative molar ratio of 7: 3. The backbone of CAPW-1 was consisted of 1,3-Galp and 1,3,6-Galp, the branches were attached to the O-6 of 1,3-Galp, and the side chains contained 1,6-Galp, 1,3,6-Galp, 1,5-linked, 1,3-linked, 1,3,5-linked, and terminal-Araf, which was attached to the O-3 of side 1,6-Galp. The bioactivity study indicated CAPW-1 could stimulate the proliferation of RAW264.7 cells and promote the secretion of nitric oxide (NO), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) with no cytotoxicity. The results suggested a potential application of CAPW-1 as an immunostimulant for the treatment of diseases such as infection and tumor.

Glyco-Coated CdSe/ZnS Quantum Dots as Nanoprobes for Carbonic Anhydrase IX Imaging in Cancer Cells.

The bioimaging of cancer cells by the specific targeting of overexpressed biomarkers is an approach that holds great promise in the identification of selective diagnostic tools. Tumor-associated human carbonic anhydrase (hCA) isoforms IX and XII have been considered so far as well-defined biomarkers, with their expression correlating with cancer progression and aggressiveness. Therefore, the availability of highly performant fluorescent tools tailored for their targeting and able to efficiently visualize such key targets is in high demand. We report here on the design and synthesis of a kind of quantum dot (QD)-based fluorescent glyconanoprobe coated with a binary mixture of ligands, which, according to the structure of the terminal domains, impart specific property sets to the fluorescent probe. Specifically, monosaccharide residues ensured the dispersibility in the biological medium, CA inhibitor residues provided specific targeting of membrane-anchored hCA IX overexpressed on bladder cancer cells, and the quantum dots imparted the optical/fluorescence properties.

Biosynthesis of hyaluronan in engineered Escherichia coli via the secretion of thermophilic exo-mannanase using palm kernel cake as the carbon source

The potential of palm kernel cake (PKC) wastes as feedstocks for the production of hyaluronic acid (HA) using engineered Escherichia coli has been investigated. Herein, we report a novel thermophilic exo-β-D-mannanase TFMS, which exhibits superior enzymatic properties and more efficiently hydrolyzes PKC to yield oligosaccharides composed of 1-m to 10-m monosaccharide residues. By optimizing signal peptides, we achieved high-level secretory production of TFMS in engineered chassis strain, which could effectively release oligosaccharides from PKC for cell growth. Our results confirm that the chassis strain maintains relatively high cell-growth rates and biomass in PKC media with approximately 70.5% levels of that in LB media. Furthermore, hasA, a HA synthase gene from Streptococcus zooepidemicus, was expressed in chassis strain to produce a relatively high HA accumulation of 192 mg/L from PKC. This study provides a new approach for developing feedstock utilizations of PKC wastes by constructing efficient microbial cell factories to biosynthesize value-added products.

Structural Characterization of Pectic Polysaccharides in the Cell Wall of Stevens Variety Cranberry Using Highly Specific Pectin-Hydrolyzing Enzymes.

The potential of poly- and oligosaccharides as functional ingredients depends on the type and glycosidic linkages of their monosaccharide residues, which determine their techno-functional properties, their digestibility and their fermentability. To isolate the pectic polysaccharides of cranberry, alcohol insoluble solids were first obtained from pomace. A sequential extraction with hot phosphate buffer, chelating agents (CH), diluted (DA) and concentrated sodium hydroxide was then carried out. Pectic polysaccharides present in CH and DA extracts were purified by anion exchange and gel filtration chromatography, then sequentially exposed to commercially available pectin-degrading enzymes (endo-polygalacturonase, pectin lyase and endo-arabinanase/endo-galactanase/both). The composition and linkages of the generated fragments revealed important characteristic features, including the presence of homogalacturonan with varied methyl esterification extent, branched type I arabinogalactan and pectic galactan. The presence of arabinan with galactose branches was suggested upon the analysis of the fragments by LC-MS.

A Rapid and Mild Sulfation Strategy Reveals Conformational Preferences in Therapeutically Relevant Sulfated Xylooligosaccharides.

Although sulfated xylooligosaccharides are promising therapeutic leads for a multitude of afflictions, the structural complexity and heterogeneity of commercially deployed forms (e. g. Pentosan polysulfate 1) complicates their path to further clinical development. We describe herein the synthesis of the largest homogeneous persulfated xylooligomers prepared to date, comprising up to eight xylose residues, as standards for biological studies. Near quantitative sulfation was accomplished using a remarkably mild and operationally simple protocol which avoids the need for high temperatures and a large excess of the sulfating reagent. Moreover, the sulfated xylooligomer standards so obtained enabled definitive identification of a pyridinium contaminant in a sample of a commercially prepared Pentosan drug and provided significant insights into the conformational preferences of the constituent persulfated monosaccharide residues. As the spatial distribution of sulfates is a key determinant of the binding of sulfated oligosaccharides to endogenous targets, these findings have broad implications for the advancement of Pentosan-based treatments.