WorldWideScience

Sample records for chemoselective oligosaccharide synthesis

  1. Chemoselective Synthesis of Carbamates using CO2 as Carbon Source.

    Science.gov (United States)

    Riemer, Daniel; Hirapara, Pradipbhai; Das, Shoubhik

    2016-08-01

    Synthesis of carbamates directly from amines using CO2 as the carbon source is a straightforward and sustainable approach. Herein, we describe a highly effective and chemoselective methodology for the synthesis of carbamates at room temperature and atmospheric pressure. This methodology can also be applied to protect the amino group in amino acids and peptides, and also to synthesize important pharmaceuticals. PMID:27376902

  2. Chemoselective Synthesis of Polysubstituted Pyridines from Heteroaryl Fluorosulfates.

    Science.gov (United States)

    Zhang, Enxuan; Tang, Jiaze; Li, Suhua; Wu, Peng; Moses, John E; Sharpless, K Barry

    2016-04-11

    A selection of heteroaryl fluorosulfates were readily synthesized using commercial SO2 F2 gas. These substrates are highly efficient coupling partners in the Suzuki reaction. Through judicious selection of Pd catalysts the fluorosulfate functionality is differentiated from bromide and chloride; the order of reactivity being: -Br> -OSO2 F> -Cl. Exploiting this trend allowed the stepwise chemoselective synthesis of a number of polysubstituted pyridines, including the drug Etoricoxib. PMID:26990693

  3. Automated synthesis of sialylated oligosaccharides

    Directory of Open Access Journals (Sweden)

    Davide Esposito

    2012-09-01

    Full Text Available Sialic acid-containing glycans play a major role in cell-surface interactions with external partners such as cells and viruses. Straightforward access to sialosides is required in order to study their biological functions on a molecular level. Here, automated oligosaccharide synthesis was used to facilitate the preparation of this class of biomolecules. Our strategy relies on novel sialyl α-(2→3 and α-(2→6 galactosyl imidates, which, used in combination with the automated platform, provided rapid access to a small library of conjugation-ready sialosides of biological relevance.

  4. Chemoselective approaches to glycoprotein assembly

    International Nuclear Information System (INIS)

    Oligosaccharides on proteins and lipids play central roles in human health and disease. The molecular analysis of glycoconjugate function has benefited tremendously from new methods for their chemical synthesis, which provides homogeneous material not attainable from biosynthetic systems. Still, glycoconjugate synthesis requires the manipulation of multiple stereocenters and protecting groups and remains the domain of a few expert laboratories around the world. This account summarizes chemoselective approaches for assembling homogeneous glycoconjugates that attempt to reduce the barriers to their synthesis. The objective of these methods is to make glycoconjugate synthesis accessible to a broader community, thereby accelerating progress in glycobiology

  5. Approaches to chemical synthesis of pectic oligosaccharides

    DEFF Research Database (Denmark)

    Nepogodiev, Sergei A.; Field, Robert A.; Damager, Iben

    2011-01-01

    at the formation of specific glycosidic linkages as they are present in the target oligosaccharides. Challenges in synthesis of pectic oligosaccharides are associated with often poor stereoselectivity of glycosylation reactions between GA and GD, in particular for the construction of 1,2-cis-glycosidic linkages...... representing all three major types of pectic polysaccharide: homogalacturonan (HG), rhamnogalacturonan-I (RG-I) and rhamnogalacturonan-II (RG-II). Such molecules have been synthesized by sequential coupling of building blocks, the so-called glycosyl donors (GD) and glycosyl acceptors (GA), which aimed...... group strategies for GA and GD, glycosylation methodologies and general strategies for oligosaccharide assembly are described with the focus on pectin fragments. Synthetic routes to fragments of each type of pectic polysaccharides are discussed in detail in separate sections and structures of all...

  6. Automated solid-phase synthesis of oligosaccharides containing sialic acids

    Directory of Open Access Journals (Sweden)

    Chian-Hui Lai

    2015-05-01

    Full Text Available A sialic acid glycosyl phosphate building block was designed and synthesized. This building block was used to prepare α-sialylated oligosaccharides by automated solid-phase synthesis selectively.

  7. Metabolic engineering of microbes for oligosaccharide and polysaccharide synthesis

    OpenAIRE

    Chen Rachel; Ruffing Anne

    2006-01-01

    Abstract Metabolic engineering has recently been embraced as an effective tool for developing whole-cell biocatalysts for oligosaccharide and polysaccharide synthesis. Microbial catalysts now provide a practical means to derive many valuable oligosaccharides, previously inaccessible through other methods, in sufficient quantities to support research and clinical applications. The synthesis process based upon these microbes is scalable as it avoids expensive starting materials. Most impressive...

  8. Selective synthesis of Rh5 carbonyl clusters within a polyamine dendrimer for chemoselective reduction of nitro aromatics.

    Science.gov (United States)

    Maeno, Zen; Mitsudome, Takato; Mizugaki, Tomoo; Jitsukawa, Koichiro; Kaneda, Kiyotomi

    2014-06-21

    The selective synthesis of the [Rh5(CO)15](-) cluster within the PPI dendrimer was successfully demonstrated. The dendrimer-encapsulated [Rh5(CO)15](-) was resistant to decomposition under the catalytic reaction conditions and exhibited extremely high selectivity for the chemoselective reduction of nitro groups of various nitro aromatics with other reducible groups using CO/H2O as a reductant.

  9. Solid-phase oligosaccharide and glycopeptide synthesis using glycosynthases

    DEFF Research Database (Denmark)

    Tolborg, Jakob Fjord; Petersen, Lars; Jensen, Knud Jørgen;

    2002-01-01

    Enzymatic approaches for the preparation of oligosaccharides are interesting alternatives to traditional chemical synthesis, the main advantage being the regio- and stereoselectivity offered without the need for protecting groups. The use of solid-phase techniques offers easy workup procedures an...

  10. Galacto-oligosaccharide synthesis using immobilized β-galactosidase

    NARCIS (Netherlands)

    Benjamins, Frédéric

    2014-01-01

    Galacto-oligosaccharides (GOS) are carbohydrates generated from glucose and galactose, which exhibit prebiotic functionality. In the colon they selectively stimulate the growth of beneficial bacteria. This thesis provides an overview of historical and current literature on the synthesis of (galacto-

  11. Direct chemoselective synthesis of glyconanoparticles from unprotected reducing glycans and glycopeptide aldehydes

    DEFF Research Database (Denmark)

    Thygesen, Mikkel Boas; Sørensen, Kasper Kildegaard; Cló, Emiliano;

    2009-01-01

    Chemoselective oxime coupling was used for facile conjugation of unprotected, reducing glycans and glycopeptide aldehydes with core-shell gold nanoparticles carrying reactive aminooxy groups on the organic shell.......Chemoselective oxime coupling was used for facile conjugation of unprotected, reducing glycans and glycopeptide aldehydes with core-shell gold nanoparticles carrying reactive aminooxy groups on the organic shell....

  12. Metabolic engineering of microbes for oligosaccharide and polysaccharide synthesis

    Directory of Open Access Journals (Sweden)

    Chen Rachel

    2006-07-01

    Full Text Available Abstract Metabolic engineering has recently been embraced as an effective tool for developing whole-cell biocatalysts for oligosaccharide and polysaccharide synthesis. Microbial catalysts now provide a practical means to derive many valuable oligosaccharides, previously inaccessible through other methods, in sufficient quantities to support research and clinical applications. The synthesis process based upon these microbes is scalable as it avoids expensive starting materials. Most impressive is the high product concentrations (up to 188 g/L achieved through microbe-catalyzed synthesis. The overall cost for selected molecules has been brought to a reasonable range (estimated $ 30–50/g. Microbial synthesis of oligosaccharides and polysaccharides is a carbon-intensive and energy-intensive process, presenting some unique challenges in metabolic engineering. Unlike nicotinamide cofactors, the required sugar nucleotides are products of multiple interacting pathways, adding significant complexity to the metabolic engineering effort. Besides the challenge of providing the necessary mammalian-originated glycosyltransferases in active form, an adequate uptake of sugar acceptors can be an issue when another sugar is necessary as a carbon and energy source. These challenges are analyzed, and various strategies used to overcome these difficulties are reviewed in this article. Despite the impressive success of the microbial coupling strategy, there is a need to develop a single strain that can achieve at least the same efficiency. Host selection and the manner with which the synthesis interacts with the central metabolism are two important factors in the design of microbial catalysts. Additionally, unlike in vitro enzymatic synthesis, product degradation and byproduct formation are challenges of whole-cell systems that require additional engineering. A systematic approach that accounts for various and often conflicting requirements of the synthesis holds

  13. Efficient, chemoselective synthesis of immunomicelles using single-domain antibodies with a C-terminal thioester

    Directory of Open Access Journals (Sweden)

    Raats Jos MH

    2009-07-01

    Full Text Available Abstract Background Classical bioconjugation strategies for generating antibody-functionalized nanoparticles are non-specific and typically result in heterogeneous compounds that can be compromised in activity. Expression systems based on self-cleavable intein domains allow the generation of recombinant proteins with a C-terminal thioester, providing a unique handle for site-specific conjugation using native chemical ligation (NCL. However, current methods to generate antibody fragments with C-terminal thioesters require cumbersome refolding procedures, effectively preventing application of NCL for antibody-mediated targeting and molecular imaging. Results Targeting to the periplasm of E. coli allowed efficient production of correctly-folded single-domain antibody (sdAb-intein fusions proteins. On column purification and 2-mercapthoethanesulfonic acid (MESNA-induced cleavage yielded single-domain antibodies with a reactive C-terminal MESNA thioester in good yields. These thioester-functionalized single-domain antibodies allowed synthesis of immunomicelles via native chemical ligation in a single step. Conclusion A novel procedure was developed to obtain soluble, well-folded single-domain antibodies with reactive C-terminal thioesters in good yields. These proteins are promising building blocks for the chemoselective functionalization via NCL of a broad range of nanoparticle scaffolds, including micelles, liposomes and dendrimers.

  14. A concise, efficient synthesis of sugar-based benzothiazoles through chemoselective intramolecular C-S coupling

    KAUST Repository

    Shen, Chao

    2012-01-01

    Sugar-based benzothiazoles are a new class of molecules promising for many biological applications. Here, we have synthesized a wide range of sugar-based benzothiazoles from readily accessible glycosyl thioureas by chemoselective, palladium-catalyzed C-S coupling reactions. Corroborated by theoretical calculations, a mechanistic investigation indicates that the coordination to the palladium by a pivaloyl carbonyl group and the presence of intramolecular hydrogen bonding play important roles in the efficiency and chemoselectivity of reaction. These fluorescent glycoconjugates can be observed to readily enter mammalian tumor cells and exhibit potential in vitro antitumor activity. This journal is © The Royal Society of Chemistry 2012.

  15. Total Synthesis of (+)-SCH 351448: Efficiency via Chemoselectivity and Redox-Economy Powered by Metal Catalysis.

    Science.gov (United States)

    Wang, Gang; Krische, Michael J

    2016-07-01

    The polyketide natural product (+)-SCH 351448, a macrodiolide ionophore bearing 14 stereogenic centers, is prepared in 14 steps (LLS). In eight prior syntheses, 22-32 steps were required. Multiple chemoselective and redox-economic functional group interconversions collectively contribute to a step-change in efficiency. PMID:27337561

  16. Methods for Improving Enzymatic Trans-glycosylation for Synthesis of Human Milk Oligosaccharide Biomimetics

    DEFF Research Database (Denmark)

    Zeuner, Birgitte; Jers, Carsten; Mikkelsen, Jørn Dalgaard;

    2014-01-01

    Recently, significant progress has been made within enzymatic synthesis of biomimetic, functional glycans, including, for example, human milk oligosaccharides. These compounds are mainly composed of N-acetylglucosamine, fucose, sialic acid, galactose, and glucose, and their controlled enzymatic...

  17. Detailed kinetic model describing new oligosaccharides synthesis using different β-galactosidases

    OpenAIRE

    Rodríguez Fernández, María; Cardelle-Cobas, A.; Villamiel, M.; Banga, Julio R.

    2011-01-01

    The production of prebiotic galactooligosaccharides (GOS) from lactose has been widely 20 studied whereas the synthesis of new prebiotic oligosaccharides with improved properties as 21 those derived from lactulose is receiving an increasing interest. Understanding the mechanism 22 of enzymatic oligosaccharides synthesis from lactulose would help to improve the quality of 23 the products in a rational way as well as to increase the production efficiency by optimally 24 selecting...

  18. A Metal and Base-Free Chemoselective Primary Amination of Boronic Acids Using Cyanamidyl/Arylcyanamidyl Radical as Aminating Species: Synthesis and Mechanistic Studies by Density Functional Theory.

    Science.gov (United States)

    Chatterjee, Nachiketa; Arfeen, Minhajul; Bharatam, Prasad V; Goswami, Avijit

    2016-06-17

    An efficient, metal and base-free, chemoselective synthesis of aryl-, heteroaryl-, and alkyl primary amines from the corresponding boronic acids has been achieved at ambient temperature mediated by [bis(trifluoroacetoxy)iodo]benzene (PIFA) and N-bromosuccinimide (NBS) using cyanamidyl/arylcyanamidyl radicals as the aminating species. The primary amine compounds were initially obtained as their corresponding ammonium trifluoroacetate salts which, on treatment with aq NaOH, provide the free amines. Finally, the primary amines were isolated through column chromatography over silica-gel using hexane-EtOAc solvent system as the eluent. The reactions are sufficiently fast, completing within 1 h. Quantum chemical calculations in combination with experimental observations validate that the ipso amination of substituted boronic acids involves the formation of cyanamidyl/arylcyanamidyl radical, followed by regiospecific interaction of its nitrile-N center with boron atom of the boronic acids, leading to chemoselective primary amination. PMID:27182931

  19. Powder lemon juice containing oligosaccharides obtained by dextransucrase acceptor reaction synthesis and dehydrated in sprouted bed.

    Science.gov (United States)

    Coelho, Raquel Macedo Dantas; Araújo, Antônia Daiana Andrade; Fontes, Cláudia Patrícia Mourão Lima; da Silva, Ana Raquel Araujo; da Costa, José Maria Correia; Rodrigues, Sueli

    2015-09-01

    Oligosaccharides can be synthesized using the sugars present in the fruit juices through the dextransucrase acceptor reaction. In the present work, the effect of reducing sugar and sucrose concentration on oligosaccharide formation in lemon juice was evaluated through response surface methodology. The oligosaccharide formation in lemon juice was favored at high concentrations of sucrose (75 g/L) and reducing sugar (75 g/L). At this synthesis conditions, an oligosaccharide concentration of 94.81 g/L was obtained with a conversion of 63.21% of the initial sugars into the target product. Oligosaccharides with degree of polymerization up to 11 were obtained. The lemon juice was dehydrated in spouted bed using maltodextrin as drying adjuvant. The powder obtained at 60°C with 20 % maltodextrin presented low moisture (2.24 %), low water activity (Aw = 0.18) and the lowest reconstitution time (~46 s). The results showed that lemon juice is suitable for oligosaccharides enzyme synthesis and can be dehydrated in spouted bed. PMID:26345014

  20. Oxacarbenium ion intermediates in the stereoselective synthesis of anionic oligosaccharides

    NARCIS (Netherlands)

    Dinkelaar, Jasper

    2009-01-01

    In this thesis new strategies towards biologically active oligosaccharides are described. In addition a detailed mechanistic study is performed to investigate the stereodirecting capacity of glycosyl C-5 substituents in systems that were devoid of any other stereodirecting factors. The postulated m

  1. Solid-phase oligosaccharide synthesis with tris(alkoxy)benzyl amine (BAL) safety-catch anchoring

    DEFF Research Database (Denmark)

    Tolborg, Jakob Fjord; Jensen, Knud Jørgen

    2000-01-01

    A tris(alkoxy)benzylamine (BAL) handle strategy was developed for safety-catch anchoring of D-glucosamine derivatives in solid-phase synthesis of oligosaccharides; the linkage between the BAL handle and the amine proved stable to conc. TFA and Lewis acids, but after N-acylation the amide could...

  2. Synthesis of Human Milk Oligosaccharides and Regioselective Ring Opening of Oxabicycles

    DEFF Research Database (Denmark)

    Jennum, Camilla Arboe

    the fucose is also attached in the same pot. In addition, pNP-neuraminic acid was synthesized for the purpose to perform activity studies on enzymes. The enzymes were designed to perform sialyl transfer reactions in the synthesis human milk oligosaccharides containing neuraminic acid. OH O HO HO O OH O HO O...

  3. Gram-scale, chemoselective synthesis of N-[2-(5-hydroxy-1H-indol-3-yl)ethyl]-2-oxopiperidine-3-carboxamide (HIOC)

    Science.gov (United States)

    Setterholm, Noah A.; Boatright, Jeffrey H.; Iuvone, P. Michael

    2015-01-01

    N-[2-(5-hydroxy-1H-indol-3-yl)ethyl]-2-oxopiperidine-3-carboxamide (HIOC) is a potent activator of the TrkB receptor in mammalian neurons and of interest because of its potential therapeutic uses. In the absence of a commercial supply of HIOC, we sought to produce several grams of material. However, a synthesis of HIOC has never been published. Herein we report the preparation of HIOC by the chemoselective N-acylation of serotonin, without using blocking groups in the key acylation step. PMID:26028783

  4. Controllable Synthesis of Mesoporous Iron Oxide Nanoparticle Assemblies for Chemoselective Catalytic Reduction of Nitroarenes.

    Science.gov (United States)

    Papadas, Ioannis T; Fountoulaki, Stella; Lykakis, Ioannis N; Armatas, Gerasimos S

    2016-03-18

    Iron(III) oxide is a low-cost material with applications ranging from electronics to magnetism, and catalysis. Recent efforts have targeted new nanostructured forms of Fe2O3 with high surface area-to-volume ratio and large pore volume. Herein, the synthesis of 3D mesoporous networks consisting of 4-5 nm γ-Fe2O3 nanoparticles by a polymer-assisted aggregating self-assembly method is reported. Iron oxide assemblies obtained from the hybrid networks after heat treatment have an open-pore structure with high surface area (up to 167 m(2)g(-1)) and uniform pores (ca. 6.3 nm). The constituent iron oxide nanocrystals can undergo controllable phase transition from γ-Fe2O3 to α-Fe2O3 and to Fe3O4 under different annealing conditions while maintaining the 3D structure and open porosity. These new ensemble structures exhibit high catalytic activity and stability for the selective reduction of aryl and alkyl nitro compounds to the corresponding aryl amines and oximes, even in large-scale synthesis. PMID:26880681

  5. History, synthesis, properties, applications and regulatory issues of prebiotic oligosaccharides

    OpenAIRE

    Tymczyszyn, E. E.; Santos, M. I.; Costa, Maria do Céu; Illanes, A.; Gomez-Zavaglia, A.

    2014-01-01

    In this chapter, the health promoting effects of carbohydrate prebiotics are addressed. A brief description of their synthesis, thermo-physical properties, mechanisms of action, technological applications and current regulatory issues are presented.

  6. Thermostable β-galactosidases for the synthesis of human milk oligosaccharides

    DEFF Research Database (Denmark)

    Zeuner, Birgitte; Nyffenegger, Christian; Mikkelsen, Jørn Dalgaard;

    2016-01-01

    T; Gal-β(1,4)-GlcNAc-β(1,3)-Gal-β(1,4)-Glc). In order to reduce reaction times and be able to work at temperatures, which are less welcoming to microbial growth, the current study investigates the possibility of using thermostable β-galactosidases for synthesis of LNnT and N-acetyllactosamine (Lac......NAc, resulting in 5-6 times higher reaction yields and significantly shorter reaction times.......Human milk oligosaccharides (HMOs) designate a unique family of bioactive lactose-based molecules present in human breast milk. Using lactose as a cheap donor, some β-galactosidases (EC 3.2.1.23) can catalyze transgalactosylation to form the human milk oligosaccharide lacto- N-neotetraose (LNn...

  7. Esterification and Chemoselective Synthesis of R-Tetrahydrothiazo-2- thione-4-carboxylic Esters Catalyzed by TiCl4

    Institute of Scientific and Technical Information of China (English)

    SHANG Yan-mei; LI Jing; SONG Zhi-guang; LI Ye-zhi; HUANG Hua-min

    2007-01-01

    A series of esters of R-tetrahydrothiazo-2-thione-4-carboxylic acid[ R-TTCA] was synthesized by direct esterification of R-TTCA with alcohols(CH3OH, C2H5OH, n-C3H7OH, i-C3H7OH, n-C4H9OH, sec-C4H9OH) in the presence of TiCl4 as the catalyst at room temperature without using any other solvent or dehydrant in high yields,91.6%-99.1% for primary alcohols and 55%- 80% for secondary alcohols. The catalyst has a strong chemoselecfive activity for the esterification of primary alcohols with R-TTCA in the presence of secondary alcohols. Owing to high yield, high chemoselectivity, and mild conditions used, this is an efficient method for the esterification of primary alcohols with R-TTCA.

  8. Zinc zirconium phosphate as an efficient catalyst for chemoselective synthesis of 1,1-diacetates under solvent-free conditions

    Indian Academy of Sciences (India)

    Abdol R Hajipour; Hirbod Karimi

    2015-11-01

    In the present study, a mild, rapid, and efficient method for the protection of aldehydes with acetic anhydride (AA) in the presence of zinc zirconium phosphate (ZPZn) as a nano catalyst, at room temperature is reported. Selective conversion of aldehydes was observed in the presence of ketones. Under these conditions, different aldehydes bearing electron-withdrawing and electron-donating substituents were reacted with AA and the corresponding 1,1-diacetates (acylals) were obtained in high to excellent yields. The steric and electronic properties of the different substrates had a significant influence on the reaction conditions. Also, the deprotection of 1,1-diacetates has been achieved using this catalyst in water. This nanocatalyst was characterized by several physico-chemical techniques. It was recovered easily from the reaction mixture, regenerated and reused at least 7 times without significant loss in catalytic activity. This protocol has the advantages of easy availability, stability, reusability of the eco-friendliness, chemoselectivity, simple experimental and work-up procedure, solvent-free conditions and usage of only a stoichiometric amount of AA.

  9. Efficient synthesis and activity of beneficial intestinal flora of two lactulose-derived oligosaccharides.

    Science.gov (United States)

    Zhu, Zhen-Yuan; Cui, Di; Gao, Hui; Dong, Feng-Ying; Liu, Xiao-Cui; Liu, Fei; Chen, Lu; Zhang, Yong-Min

    2016-05-23

    Lactulose is considered as a prebiotic because it promotes the intestinal proliferation of Lactobacillus acidophilus which is added to various milk products. Moreover, lactulose is used in pharmaceuticals as a gentle laxative and to treat hyperammonemia. This study was aimed at the total synthesis of two Lactulose-derived oligosaccharides: one is 3-O-β-d-galactopyranosyl-d-fructose, d-fructose and β-d-galactose bounded together with β-1,3-glycosidic bound, the other is 1-O-β-d-galactopyranosyl-d-fructose, d-fructose and β-d-galactose bounded together with β-1,1-glycosidic bound, which were accomplished in seven steps from d-fructose and β-d-galactose and every step of yield above 75%. This synthetic route provided a practical and effective synthetic strategy for galactooligosaccharides, starting from commercially available monosaccharides. Then we evaluated on their prebiotic properties in the search for potential agents of regulating and improving the intestinal flora of human. The result showed that the prebiotic properties of Lactulose-derived oligosaccharides was much better than Lactulose. Among them, 3-O-β-d-galactopyranosyl-d-fructose displayed the most potent activity of proliferation of L. acidophilus. PMID:26974370

  10. Methods for improving enzymatic trans-glycosylation for synthesis of human milk oligosaccharide biomimetics.

    Science.gov (United States)

    Zeuner, Birgitte; Jers, Carsten; Mikkelsen, Jørn Dalgaard; Meyer, Anne S

    2014-10-01

    Recently, significant progress has been made within enzymatic synthesis of biomimetic, functional glycans, including, for example, human milk oligosaccharides. These compounds are mainly composed of N-acetylglucosamine, fucose, sialic acid, galactose, and glucose, and their controlled enzymatic synthesis is a novel field of research in advanced food ingredient chemistry, involving the use of rare enzymes, which have until now mainly been studied for their biochemical significance, not for targeted biosynthesis applications. For the enzymatic synthesis of biofunctional glycans reaction parameter optimization to promote "reverse" catalysis with glycosidases is currently preferred over the use of glycosyl transferases. Numerous methods exist for minimizing the undesirable glycosidase-catalyzed hydrolysis and for improving the trans-glycosylation yields. This review provides an overview of the approaches and data available concerning optimization of enzymatic trans-glycosylation for novel synthesis of complex bioactive carbohydrates using sialidases, α-l-fucosidases, and β-galactosidases as examples. The use of an adequately high acceptor/donor ratio, reaction time control, continuous product removal, enzyme recycling, and/or the use of cosolvents may significantly improve trans-glycosylation and biocatalytic productivity of the enzymatic reactions. Protein engineering is also a promising technique for obtaining high trans-glycosylation yields, and proof-of-concept for reversing sialidase activity to trans-sialidase action has been established. However, the protein engineering route currently requires significant research efforts in each case because the structure-function relationship of the enzymes is presently poorly understood.

  11. Simultaneous synthesis of mixtures of lactulose and galacto-oligosaccharides and their selective fermentation.

    Science.gov (United States)

    Guerrero, Cecilia; Vera, Carlos; Acevedo, Fernando; Illanes, Andrés

    2015-09-10

    Lactulose and galacto-oligosaccharides (GOS) are well recognized prebiotics derived from lactose. In the synthesis of lactulose with β-galactosidases GOS are also produced, but the ratio of lactulose and GOS in the product can be tuned at will, depending on the operation conditions, so to obtain an optimal product distribution in terms of prebiotic potential. The selectivity of fermentation of each carbohydrate alone as well as mixtures of both was determined using pH-controlled anaerobic batch cultures with faecal inoculum. Within the experimental range considered, lactulose/GOS molar ratio of 4 resulted in the highest selectivity for Bifidobacterium and Lactobacillus/Enterococcus, so this ratio was selected as the target for the synthesis of lactulose from fructose and lactose with Aspergillus oryzae β-galactosidase. Synthesis was optimized using response surface methodology, considering temperature, initial concentrations of acceptor sugars and fructose/lactose molar ratio as key variables, with the aim of maximizing lactulose yield at the optimal product distribution in terms of prebiotic potential (lactulose/GOS molar ratio of 4). Under optimal conditions (50°C, 50%w/w total initial concentrations of sugars and fructose/lactose molar ratio of 6.44), lactulose yield of 0.26g of lactulose produced per g of initial lactose was obtained at the optimal product distribution. PMID:26080080

  12. Engineering a thermostable Halothermothrix orenii β-glucosidase for improved galacto-oligosaccharide synthesis.

    Science.gov (United States)

    Hassan, Noor; Geiger, Barbara; Gandini, Rosaria; Patel, Bharat K C; Kittl, Roman; Haltrich, Dietmar; Nguyen, Thu-Ha; Divne, Christina; Tan, Tien Chye

    2016-04-01

    Lactose is produced in large amounts as a by-product from the dairy industry. This inexpensive disaccharide can be converted to more useful value-added products such as galacto-oligosaccharides (GOSs) by transgalactosylation reactions with retaining β-galactosidases (BGALs) being normally used for this purpose. Hydrolysis is always competing with the transglycosylation reaction, and hence, the yields of GOSs can be too low for industrial use. We have reported that a β-glucosidase from Halothermothrix orenii (HoBGLA) shows promising characteristics for lactose conversion and GOS synthesis. Here, we engineered HoBGLA to investigate the possibility to further improve lactose conversion and GOS production. Five variants that targeted the glycone (-1) and aglycone (+1) subsites (N222F, N294T, F417S, F417Y, and Y296F) were designed and expressed. All variants show significantly impaired catalytic activity with cellobiose and lactose as substrates. Particularly, F417S is hydrolytically crippled with cellobiose as substrate with a 1000-fold decrease in apparent k cat, but to a lesser extent affected when catalyzing hydrolysis of lactose (47-fold lower k cat). This large selective effect on cellobiose hydrolysis is manifested as a change in substrate selectivity from cellobiose to lactose. The least affected variant is F417Y, which retains the capacity to hydrolyze both cellobiose and lactose with the same relative substrate selectivity as the wild type, but with ~10-fold lower turnover numbers. Thin-layer chromatography results show that this effect is accompanied by synthesis of a particular GOS product in higher yields by Y296F and F417S compared with the other variants, whereas the variant F417Y produces a higher yield of total GOSs. PMID:26621798

  13. De Novo Synthesis of Furanose Sugars: Catalytic Asymmetric Synthesis of Apiose and Apiose-Containing Oligosaccharides.

    Science.gov (United States)

    Kim, Mijin; Kang, Soyeong; Rhee, Young Ho

    2016-08-01

    A de novo synthetic method towards apiose, a structurally unusual furanose, is reported. The key feature is sequential metal catalysis consisting of the palladium-catalyzed asymmetric intermolecular hydroalkoxylation of an alkoxyallene and subsequent ring-closing metathesis (RCM). This strategy enabled the efficient synthesis of various apiose-containing disaccharides and a unique convergent synthesis of trisaccharides. PMID:27381592

  14. [Recent progress on galacto-oligosaccharides synthesis by microbial beta-galactosidase--a review].

    Science.gov (United States)

    Lu, Lili; Li, Zhengyi; Xiao, Min

    2008-07-01

    Galacto-oligosaccharides are among the most promising non-digestible oligosaccharides that are recognized as prebiotics. Commercial GOS are synthesized from lactose using the transglycosylation activity of beta-galactosidase from microorganisms. The structure of GOS varies with different enzyme source. The oligosaccharide yields of GOS produced by natural enzymes are generally 20%-45% and they could be improved by artificial enzyme. Reaction conditions also have effect on the oligosaccharide yield. Using enzymes in water-hydrophobic solvent mixtures or reverse micelles may improve the yield to some extent. GOS can be large-scale synthesized by packed bed reactor, plugflow reactor or membrane reactor. The glucose and lactose in the GOS products can be removed by using chromatography, enzyme oxidation, nanofiltration membrane or microbial fermentation.

  15. Synthesis and Fermentation Properties of Novel Galacto-Oligosaccharides by β-Galactosidases from Bifidobacterium Species

    OpenAIRE

    Rabiu, Bodun A.; Jay, Andrew J.; Glenn R Gibson; Rastall, Robert A.

    2001-01-01

    β-Galactosidase enzymes were extracted from pure cultures of Bifidobacterium angulatum, B. bifidum BB-12, B. adolescentis ANB-7, B. infantis DSM-20088, and B. pseudolongum DSM-20099 and used in glycosyl transfer reactions to synthesize oligosaccharides from lactose. At a lactose concentration of 30% (wt/wt) oligosaccharide yields of 24.7 to 47.6% occurred within 7 h. Examination of the products by thin-layer chromatography and methylation analysis revealed distinct product derived spectra fro...

  16. Synthesis of 2,6-disubstituted pyridin-3-yl C-2'-deoxyribonucleosides through chemoselective transformations of bromo-chloropyridine C-nucleosides.

    Science.gov (United States)

    Kubelka, Tomáš; Slavětínská, Lenka; Eigner, Václav; Hocek, Michal

    2013-07-28

    2-Bromo-6-chloro- and 6-bromo-2-chloropyridin-3-yl deoxyribonucleosides were prepared by the Heck coupling of bromo-chloro-iodopyridines with TBS-protected deoxyribose glycal. Some of their Pd-catalyzed cross-coupling reactions proceeded chemoselectively at the position of the bromine, whereas nucleophilic substitutions were unselective and gave mixtures of products. The mono-substituted intermediates were used for another coupling or nucleophilic substitution giving rise to a small library of title 2,6-disubstituted pyridine C-deoxyribonucleosides. The title nucleosides did not exert antiviral or cytostatic effects.

  17. Synthesis of oligosaccharides derived from lactulose (OsLu using soluble and immobilized Aspergillus oryzae b-galactosidase

    Directory of Open Access Journals (Sweden)

    ALEJANDRA eCARDELLE COBAS

    2016-03-01

    Full Text Available b-galactosidase from Aspergillus oryzae offers a high yield for the synthesis of oligosaccharides derived from lactulose (OsLu by transgalactosylation. Oligosaccharides with degree of polymerization (DP ≥ 3 have shown to possess higher in vitro bifidogenic effect than di- and tetrasaccharides. Thus, in this work, an optimization of reaction conditions affecting the specific selectivity of A. oryzae b-galactosidase for synthesis of OsLu has been carried out to enhance OsLu with DP ≥ 3 production. Assays with b-galactosidase immobilized onto a glutaraldehyde-agarose support were also carried out with the aim of making the process cost-effective and industrially viable. Optimal conditions with both soluble and immobilized enzyme for the synthesis of OsLu with DP ≥ 3 were 50 °C, pH 6.5, 450 g/L of lactulose and 8 U/mL of enzyme, reaching yields of ca. 50% (w/v of total OsLu and ca. 20% (w/v of OsLu-3, being 6′-galactosyl-lactulose the major one, after a short reaction time. Selective formation of disaccharides, however, was favored at 60 °C, pH 4.5, 450 g/L of lactulose and 8 U/mL of enzyme. Immobilization increased the enzymatic stability to temperature changes and allowed to reuse the enzyme. We can conclude that the use, under determined optimal conditions, of the A. oryzae b-galactosidase immobilized on a support of glutaraldehyde-agarose constitutes an efficient and cost-effective alternative to the use of soluble b-galactosidases for the synthesis of prebiotic OsLu mixtures.

  18. Synthesis of Oligosaccharides Derived from Lactulose (OsLu) Using Soluble and Immobilized Aspergillus oryzae β-Galactosidase

    Science.gov (United States)

    Cardelle-Cobas, Alejandra; Olano, Agustin; Irazoqui, Gabriela; Giacomini, Cecilia; Batista-Viera, Francisco; Corzo, Nieves; Corzo-Martínez, Marta

    2016-01-01

    β-Galactosidase from Aspergillus oryzae offers a high yield for the synthesis of oligosaccharides derived from lactulose (OsLu) by transgalactosylation. Oligosaccharides with degree of polymerization (DP) ≥ 3 have shown to possess higher in vitro bifidogenic effect than di- and tetrasaccharides. Thus, in this work, an optimization of reaction conditions affecting the specific selectivity of A. oryzae β-galactosidase for synthesis of OsLu has been carried out to enhance OsLu with DP ≥ 3 production. Assays with β-galactosidase immobilized onto a glutaraldehyde–agarose support were also carried out with the aim of making the process cost-effective and industrially viable. Optimal conditions with both soluble and immobilized enzyme for the synthesis of OsLu with DP ≥ 3 were 50 °C, pH 6.5, 450 g/L of lactulose, and 8 U/mL of enzyme, reaching yields of ca. 50% (w/v) of total OsLu and ca. 20% (w/v) of OsLu with DP 3, being 6′-galactosyl-lactulose the major one, after a short reaction time. Selective formation of disaccharides, however, was favored at 60 °C, pH 4.5, 450 g/L of lactulose and 8 U/mL of enzyme. Immobilization increased the enzymatic stability to temperature changes and allowed to reuse the enzyme. We can conclude that the use, under determined optimal conditions, of the A. oryzae β-galactosidase immobilized on a support of glutaraldehyde–agarose constitutes an efficient and cost-effective alternative to the use of soluble β-galactosidases for the synthesis of prebiotic OsLu mixtures. PMID:27014684

  19. Engineering a thermostable Halothermothrix orenii β-glucosidase for improved galacto-oligosaccharide synthesis

    OpenAIRE

    Hassan, Noor; Geiger, Barbara; Gandini, Rosaria; Patel, Bharat K. C.; Kittl, Roman; Haltrich, Dietmar; Nguyen, Thu-Ha; Divne, Christina; Tan, Tien Chye

    2015-01-01

    Lactose is produced in large amounts as a by-product from the dairy industry. This inexpensive disaccharide can be converted to more useful value-added products such as galacto-oligosaccharides (GOSs) by transgalactosylation reactions with retaining β-galactosidases (BGALs) being normally used for this purpose. Hydrolysis is always competing with the transglycosylation reaction, and hence, the yields of GOSs can be too low for industrial use. We have reported that a β-glucosidase from Halothe...

  20. One-pot glycosylations in the synthesis of human milk oligosaccharides

    DEFF Research Database (Denmark)

    Jennum, Camilla Arboe; Fenger, Thomas Hauch; Bruun, Linda Maria;

    2014-01-01

    in an efficient synthesis of the pentasaccharide lacto-N-neofucopentaose I, which is composed of N-acetyllactosamine, lactose, and fucose. On the other hand, a stepwise approach was found to be the preferred synthetic pathway for preparation of the isomeric lacto-N-fucopentaose I, which contains a lacto...

  1. Chemoselective Reactions of Citral: Green Syntheses of Natural Perfumes for the Undergraduate Organic Laboratory

    Science.gov (United States)

    Cunningham, Anna D.; Ham, Eun Y.; Vosburg, David A.

    2011-01-01

    Chemoselectivity is a central concept in organic synthesis and may be readily appreciated in the context of the fragrant, polyfunctional natural product citral. We describe three single-step reactions students may perform on citral to synthesize other natural perfumes: citronellal, geraniol, nerol, or epoxycitral. Each of the reactions uses a…

  2. In vitro growth of four individual human gut bacteria on oligosaccharides produced by chemoenzymatic synthesis

    DEFF Research Database (Denmark)

    Vigsnæs, Louise Kristine; Nakai, Hiroyuki; Hemmingsen, Lene;

    2013-01-01

    by chemoenzymatic synthesis (i.e. reverse phosphorolysis or transglycosylation). Fourteen of the OS are not naturally occurring and five (β-d-glucosyl-fructose, β-d-glucosyl-xylitol, α-glucosyl-(1,4)-d-mannose, α-glucosyl-(1,4)-d-xylose; α-glucosyl-(1,4)-l-fucose) have recently been synthesized for the first time...

  3. Synthesis and Antigenicity against Human Sera of a Biotin-Labeled Oligosaccharide Portion of a Glycosphingolipid from the Parasite Echinococcus multilocularis.

    Science.gov (United States)

    Hada, Noriyasu; Kitamura, Ayaka; Yamano, Kimiaki; Schweizer, Frank; Kiuchi, Fumiyuki

    2016-01-01

    Synthesis of a biotinylated analog of the carbohydrate portion of a glycosphingolipid from the parasite Echinococcus multilocularis has been achieved. We synthesized β-D-Galp-(1→6)-β-D-Galp-(1→6)-[α-L-Fucp-(1→3)]-β-D-Galp-(1→R: biotin probe) (1) and compared the antigenicity by an enzyme linked immunosorbent assay (ELISA) with biotinylated trisaccharide α-D-Galp-(1→4)-β-D-Galp-(1→3)-α-D-Galp-(1→R: biotin probe) (F), which has been shown to have significant antigenicity. Both of the oligosaccharides reacted with sera of alveolar echinococcosis (AE) patients, but showed different reactivity. Among the 60 sera of AE patients, more sera reacted with the linear sequence Galα1→4Galβ1→3GalNAcα1→R of oligosaccharide (F) than for branched compound 1. Some sera showed high specificity to one of the compound, indicating that the antibodies in the sera of AE patients differ in their specificity to recognize carbohydrate sequences of glycosphingolipids. Our results demonstrate that both of the biotinylated oligosaccharides 1 and F have good serodiagnostic potential and are complementary to detect infections caused by the parasite Echinococcus multilocularis. PMID:27373642

  4. Protein glycosylation in the phytopathogen Ustilago maydis: From core oligosaccharide synthesis to the ER glycoprotein quality control system, a genomic analysis.

    Science.gov (United States)

    Fernández-Alvarez, Alfonso; Elías-Villalobos, Alberto; Ibeas, José I

    2010-09-01

    The corn smut fungus Ustilago maydis has, over recent decades, become established as a robust pathogenic model for studying fungi-plant relationships. This use of U. maydis can be attributed to its biotrophic host interaction, easy culture and genetic manipulation in the laboratory, and the severe disease symptoms it induces in infected maize. Recent studies have shown that normal protein glycosylation is essential for pathogenic development, but dispensable for the saprophytic growth or mating. Given the relevance of protein glycosylation for U. maydis virulence, and consequently its role in the plant pathogenesis, here we review the main actors and events implicated in protein glycosylation. Furthermore, we describe the results of an in silico search, where we identify all the conserved members of the N- and O-glycosylation pathways in U. maydis at each stage: core oligosaccharide synthesis, addition of the core oligosaccharide to nascent target proteins, maturation and extension of the core oligosaccharide, and the quality control system used by the cell to avoid the presence of unfolded glycoproteins. Finally, we discuss how these genes could affect U. maydis virulence and their biotechnological implications.

  5. Green procedures for the chemoselective synthesis of acylals and their cleavage promoted by recoverable sulfonic acid based nanoporous carbon (CMK-5-SO3H)

    Indian Academy of Sciences (India)

    Daryoush Zareyee; Ehsan Mirzajanzadeh; Mohammad Ali Khalilzadeh

    2015-07-01

    A selective synthesis of gem-diacetates from the reaction of aldehydes and acetic anhydride in the presence of recyclable nanoporous solid sulfonic acid (CMK-5-SO3H) under solvent-free reaction conditions is reported. The catalyst was also found to be highly active for deprotection of resulting acylals in water.

  6. Synthesis of two hyaluronic-acid-related oligosaccharide 4-methoxyphenyl glycosides having a beta-D-glucuronic acid residue at the reducing end

    NARCIS (Netherlands)

    Halkes, K.M.; Slaghek, T.M.; Hypponen, T.K.; Kamerling, J.P.; Vliegenthart, J.F.G.

    1999-01-01

    Synthesis of two hyaluronic-acid-related oligosaccharides, the 4-methoxyphenyl β-glycosides of β-D-GlcpA-(1→3)-β-D-GlcpNAc-(1→4)-D-GlcpA and β-D-GlcpA-(1→3)-β-D-GlcpNAc-(1→4)-β-D-GlcpA-(1→3)- β-D-GJcpNAc-(1→4)-D-GlcpA, is described. D-Glucopyranosyluronic acid residues were obtained by selective oxi

  7. One-Pot Synthesis of N-(α-Peroxy)Indole/Carbazole via Chemoselective Three-Component Condensation Reaction in Open Atmosphere

    KAUST Repository

    Wang, Xinbo

    2015-11-06

    A facile one-pot synthesis of N-(α-peroxy)indole and N-(α-peroxy)carbazole has been developed using metal-free, organo-acid-catalyzed three-component condensation reactions of indole/carbazole, aldehyde, and peroxide. Based on the reaction discovered, a new synthetic proposal for Fumitremorgin A and Verruculogen is introduced. Such a protocol could be easily handled and scaled up in an open atmosphere with a wide substrate scope, enabling the construction of a new molecule library.

  8. Assembly of Oligosaccharide Libraries

    Institute of Scientific and Technical Information of China (English)

    YE Xin-Shan; WONG Chi-Huey

    2001-01-01

    @@ Carbohydrates contain an evolutionary potential of information content several orders of magnitude higher in a short sequence than any other biological oligomer due to their monomers capable of more than one linkage position, anomerity, and branching. It has been well-documented that the structural diversity of sugar oligomers leads to their involvement in many key inter-and intracellular events. Cells, bacteria, viruses, and toxins often use cell-surface carbohydrates as points of attachment. These and other important discoveries in molecular glycobiology have stimulated intense research in oligosaccharides, focusing on both their synthesis and structure-function relationship study.

  9. Assembly of Oligosaccharide Libraries

    Institute of Scientific and Technical Information of China (English)

    YE; Xin-Shan

    2001-01-01

    Carbohydrates contain an evolutionary potential of information content several orders of magnitude higher in a short sequence than any other biological oligomer due to their monomers capable of more than one linkage position, anomerity, and branching. It has been well-documented that the structural diversity of sugar oligomers leads to their involvement in many key inter-and intracellular events. Cells, bacteria, viruses, and toxins often use cell-surface carbohydrates as points of attachment. These and other important discoveries in molecular glycobiology have stimulated intense research in oligosaccharides, focusing on both their synthesis and structure-function relationship study.……

  10. Assembly of a Complex Branched Oligosaccharide by Combining Fluorous-Supported Synthesis and Stereoselective Glycosylations using Anomeric Sulfonium Ions

    NARCIS (Netherlands)

    Huang, Wei; Gao, Qi; Boons, Geert Jan

    2015-01-01

    There is an urgent need to develop reliable strategies for the rapid assembly of complex oligosaccharides. This paper presents a set of strategically selected orthogonal protecting groups, glycosyl donors modified by a (S)-phenylthiomethylbenzyl ether at C-2, and a glycosyl acceptor containing a flu

  11. Characterization of the cross-linked enzyme aggregates of a novel β-galactosidase, a potential catalyst for the synthesis of galacto-oligosaccharides.

    Science.gov (United States)

    Li, Liang; Li, Gang; Cao, Li-chuang; Ren, Guang-hui; Kong, Wei; Wang, Si-di; Guo, Geng-shan; Liu, Yu-Huan

    2015-01-28

    A novel β-galactosidase (Bgal1-3) was isolated from a marine metagenomic library and then its cross-linked enzyme aggregates (CLEAs) were prepared. The enzymatic properties of Bgal1-3-CLEAs were studied and compared with that of the free enzyme. The thermostability and storage stability of Bgal1-3 were significantly improved after it was immobilized as CLEAs. The galactose-tolerance of the enzyme was also enhanced after the immobilization, which could relieve the inhibitory effect and then tends to be beneficial for the galacto-oligosaccharides (GOS) synthesis. Moreover, higher GOS yield was achieved (59.4 ± 1.5%) by Bgal1-3-CLEAs compared to the free counterpart (57.1 ± 1.7%) in an organic-aqueous biphasic system. The GOS content and composition of the syrups synthesized by the free enzyme and Bgal1-3-CLEAs were similar and they both contained at least seven different oligosaccharides with the degree of polymerization (DP) ranging between 3 and 9. Furthermore, Bgal1-3-CLEAs maintained 82.1 ± 2.1% activity after ten cycles of reuse; the GOS yield of the tenth batch was 52.3 ± 0.3%, which was still higher than that of the most former reports. To the best of our knowledge, this is the first report on the GOS synthesis using CLEAs of β-galactosidase in an organic-aqueous biphasic system. The study not only further expands the application scope of CLEA, but also provides a potential catalyst for the synthesis of GOS with low cost. PMID:25557319

  12. Characterization of the cross-linked enzyme aggregates of a novel β-galactosidase, a potential catalyst for the synthesis of galacto-oligosaccharides.

    Science.gov (United States)

    Li, Liang; Li, Gang; Cao, Li-chuang; Ren, Guang-hui; Kong, Wei; Wang, Si-di; Guo, Geng-shan; Liu, Yu-Huan

    2015-01-28

    A novel β-galactosidase (Bgal1-3) was isolated from a marine metagenomic library and then its cross-linked enzyme aggregates (CLEAs) were prepared. The enzymatic properties of Bgal1-3-CLEAs were studied and compared with that of the free enzyme. The thermostability and storage stability of Bgal1-3 were significantly improved after it was immobilized as CLEAs. The galactose-tolerance of the enzyme was also enhanced after the immobilization, which could relieve the inhibitory effect and then tends to be beneficial for the galacto-oligosaccharides (GOS) synthesis. Moreover, higher GOS yield was achieved (59.4 ± 1.5%) by Bgal1-3-CLEAs compared to the free counterpart (57.1 ± 1.7%) in an organic-aqueous biphasic system. The GOS content and composition of the syrups synthesized by the free enzyme and Bgal1-3-CLEAs were similar and they both contained at least seven different oligosaccharides with the degree of polymerization (DP) ranging between 3 and 9. Furthermore, Bgal1-3-CLEAs maintained 82.1 ± 2.1% activity after ten cycles of reuse; the GOS yield of the tenth batch was 52.3 ± 0.3%, which was still higher than that of the most former reports. To the best of our knowledge, this is the first report on the GOS synthesis using CLEAs of β-galactosidase in an organic-aqueous biphasic system. The study not only further expands the application scope of CLEA, but also provides a potential catalyst for the synthesis of GOS with low cost.

  13. Chemoselective single-site Earth-abundant metal catalysts at metal-organic framework nodes

    Science.gov (United States)

    Manna, Kuntal; Ji, Pengfei; Lin, Zekai; Greene, Francis X.; Urban, Ania; Thacker, Nathan C.; Lin, Wenbin

    2016-08-01

    Earth-abundant metal catalysts are critically needed for sustainable chemical synthesis. Here we report a simple, cheap and effective strategy of producing novel earth-abundant metal catalysts at metal-organic framework (MOF) nodes for broad-scope organic transformations. The straightforward metalation of MOF secondary building units (SBUs) with cobalt and iron salts affords highly active and reusable single-site solid catalysts for a range of organic reactions, including chemoselective borylation, silylation and amination of benzylic C-H bonds, as well as hydrogenation and hydroboration of alkenes and ketones. Our structural, spectroscopic and kinetic studies suggest that chemoselective organic transformations occur on site-isolated, electron-deficient and coordinatively unsaturated metal centres at the SBUs via σ-bond metathesis pathways and as a result of the steric environment around the catalytic site. MOFs thus provide a novel platform for the development of highly active and affordable base metal catalysts for the sustainable synthesis of fine chemicals.

  14. Chemoselective single-site Earth-abundant metal catalysts at metal–organic framework nodes

    Energy Technology Data Exchange (ETDEWEB)

    Manna, Kuntal; Ji, Pengfei; Lin, Zekai; Greene, Francis X.; Urban, Ania; Thacker, Nathan C.; Lin, Wenbin

    2016-08-30

    Earth-abundant metal catalysts are critically needed for sustainable chemical synthesis. Here we report a simple, cheap and effective strategy of producing novel earth-abundant metal catalysts at metal–organic framework (MOF) nodes for broad-scope organic transformations. The straightforward metalation of MOF secondary building units (SBUs) with cobalt and iron salts affords highly active and reusable single-site solid catalysts for a range of organic reactions, including chemoselective borylation, silylation and amination of benzylic C–H bonds, as well as hydrogenation and hydroboration of alkenes and ketones. Our structural, spectroscopic and kinetic studies suggest that chemoselective organic transformations occur on site-isolated, electron-deficient and coordinatively unsaturated metal centres at the SBUs via σ-bond metathesis pathways and as a result of the steric environment around the catalytic site. MOFs thus provide a novel platform for the development of highly active and affordable base metal catalysts for the sustainable synthesis of fine chemicals.

  15. Surprises in the Study of Ruthenium-catalyzed Stereo- and Chemoselective Aldolizations

    Directory of Open Access Journals (Sweden)

    Elahe Keshavarz

    2015-12-01

    Full Text Available A convenient and diastereoselective method was developed for the synthesis of aldol derivatives in the presence of a catalytic amount of RuCl3.nH2O under solvent-free conditions. Aldol adducts were obtained in good yields and with high chemoselectivity in short reaction times. In this protocol, aromatic and heteroaromatic aldehydes readily participate as electrophilic cross-aldol partners with a range of cycloalkanones as ketone donors.

  16. A mild and highly chemoselective iodination of alcohol using polymer supported DMAP

    Indian Academy of Sciences (India)

    DIPARJUN DAS; JASHA MOMO H ANAL; LALTHAZUALA ROKHUM

    2016-11-01

    The synthesis of organic compounds using polymer supported catalysts and reagents, where the required product is always in solution, has been of great interest in recent years, both in industries and academia especially in pharmaceutical research. Here, a simple and efficient method for conversion of alcohols into their iodides in high yield using polymer supported 4-(Dimethylamino)pyridine (DMAP) is described. Polymer supported DMAP is used in catalytic amount and is recovered and reused several times. Additionally, this method is highly chemoselective.

  17. Assembly of a Complex Branched Oligosaccharide by Combining Fluorous-Supported Synthesis and Stereoselective Glycosylations using Anomeric Sulfonium Ions.

    Science.gov (United States)

    Huang, Wei; Gao, Qi; Boons, Geert-Jan

    2015-09-01

    There is an urgent need to develop reliable strategies for the rapid assembly of complex oligosaccharides. This paper presents a set of strategically selected orthogonal protecting groups, glycosyl donors modified by a (S)-phenylthiomethylbenzyl ether at C-2, and a glycosyl acceptor containing a fluorous tag, which makes it possible to rapidly prepare complex branched oligosaccharides of biological importance. The C-2 auxiliary controlled the 1,2-cis anomeric selectivity of the various galactosylations. The orthogonal protecting groups, 2-naphthylmethyl ether (Nap) and levulinic ester (Lev), made it possible to generate glycosyl acceptors and allowed the installation of a crowded branching point. After the glycosylations, the chiral auxiliary could be removed using acidic conditions, which was compatible with the presence of the orthogonal protecting groups Lev and Nap, thereby allowing the efficient installation of 1,2-linked glycosides. The light fluorous tag made it possible to purify the compounds by a simple filtration method using silica gel modified by fluorocarbons. The set of building blocks was successfully employed for the preparation of the carbohydrate moiety of the GPI anchor of Trypanosoma brucei, which is a parasite that causes sleeping sickness in humans and similar diseases in domestic animals. PMID:26250358

  18. Homologs of the Xenopus developmental gene DG42 are present in zebrafish and mouse and are involved in the synthesis of Nod-like chitin oligosaccharides during early embryogenesis.

    Science.gov (United States)

    Semino, C E; Specht, C A; Raimondi, A; Robbins, P W

    1996-05-14

    The Xenopus developmental gene DG42 is expressed during early embryonic development, between the midblastula and neurulation stages. The deduced protein sequence of Xenopus DG42 shows similarity to Rhizobium Nod C, Streptococcus Has A, and fungal chitin synthases. Previously, we found that the DG42 protein made in an in vitro transcription/translation system catalyzed synthesis of an array of chitin oligosaccharides. Here we show that cell extracts from early Xenopus and zebrafish embryos also synthesize chitooligosaccharides. cDNA fragments homologous to DG42 from zebrafish and mouse were also cloned and sequenced. Expression of these homologs was similar to that described for Xenopus based on Northern and Western blot analysis. The Xenopus anti-DG42 antibody recognized a 63-kDa protein in extracts from zebrafish embryos that followed a similar developmental expression pattern to that previously described for Xenopus. The chitin oligosaccharide synthase activity found in extracts was inactivated by a specific DG42 antibody; synthesis of hyaluronic acid (HA) was not affected under the conditions tested. Other experiments demonstrate that expression of DG42 under plasmid control in mouse 3T3 cells gives rise to chitooligosaccharide synthase activity without an increase in HA synthase level. A possible relationship between our results and those of other investigators, which show stimulation of HA synthesis by DG42 in mammalian cell culture systems, is provided by structural analyses to be published elsewhere that suggest that chitin oligosaccharides are present at the reducing ends of HA chains. Since in at least one vertebrate system hyaluronic acid formation can be inhibited by a pure chitinase, it seems possible that chitin oligosaccharides serve as primers for hyaluronic acid synthesis.

  19. Stable isotope labeling of oligosaccharide cell surface antigens

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, C.J.; Silks, L.A. III; Martinez, R.A. [and others

    1998-12-31

    The overall goal of this Laboratory Directed Research and Development (LDRD) project was to develop new methods for synthesis of {sup 13}C-labeled oligosaccharides that are required for nuclear magnetic resonance (NMR) studies of their solution conformation. Oligosaccharides are components of the cell`s outer surface and are involved in important processes such as cell-cell recognition and adhesion. Recently, Danishefsky and coworkers at Slone-Kettering Cancer Center developed a method for the solid-phase chemical synthesis of oligosaccharides. The specific goal of this LDRD project was to prepare uniform {sup 13}C-labeled aldohexose precursors required for the solid-phase synthesis of the Lewis blood-group antigenic determinants. We report the synthesis of {sup 13}C-labeled D-glucal, D-galactal and Fucosyl precursors. We have been collaborating with the Danishefsky group on the synthesis of the Lewis oligosaccharides and the NMR analysis of their solution conformation.

  20. Synthesis of hyaluronic-acid-related oligosaccharides and analogues, as their 4-methoxyphenyl glycosides, having N-acetyl-β-D-glucosamine at the reducing end

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Halkes, K.M.; Slaghek, T.M.; Hyppönen, T.K.; Kruiskamp, P.H.; Ogawa, T.; Kamerling, J.P.

    1998-01-01

    To contribute to the possibilities to study the ability of oligosaccharide fragments of hyaluronic acid to induce angiogenesis, several hyaluronic-acid-related oligosaccharides and their 6-O-sulfated analogues were synthesised as their 4-methoxyphenyl glycosides having 2-acetamido-2-deoxy-D-glucopyr

  1. Improvement of chitosan derivatization for the immobilization of bacillus circulans β-galactosidase and its further application in galacto-oligosaccharide synthesis.

    Science.gov (United States)

    Urrutia, Paulina; Bernal, Claudia; Wilson, Lorena; Illanes, Andrés

    2014-10-15

    Chitosan was derivatized by two methodologies to design a robust biocatalyst of immobilized Bacillus circulans β-galactosidase from a low-cost support for its further application in the synthesis of galacto-oligosaccharides (GOS). In the first one, chitosan was derivatized by cross-linking with glutaraldehyde and activated with epichlorohydrin; in the second one, cross-linking and activation were done with epichlorohydrin in a two-step process, favoring first support cross-linking and then support functionalization (C-EPI-EPI). Epoxy groups were hydrolyzed and oxidized, obtaining two supports activated with different aldehyde concentrations (100-250 μmol/g). The expressed activity and stability of the immobilized biocatalysts varied according to the derivatization methodology, showing that both the cross-linking agent and the activation degree are key parameters in the final biocatalyst performance. The best compromise between expressed activity and thermal stability was obtained using C-EPI-EPI with 200 μmol of aldehyde groups per gram of support. The immobilization conditions were optimized, obtaining a biocatalyst with 280 IU/g, immobilization yields in terms of activity and protein of 17.3 ± 0.4 and 61.5 ± 3.9%, respectively, and a high thermal stability, with a half-life of 449 times the value of the soluble enzyme. The biocatalyst was applied to the synthesis of GOS in repeated batch operation without affecting the product composition. Four successive batches were required for obtaining a cumulative specific productivity higher than the one obtained with the soluble enzyme.

  2. Automated assembly of oligosaccharides containing multiple cis-glycosidic linkages

    Science.gov (United States)

    Hahm, Heung Sik; Hurevich, Mattan; Seeberger, Peter H.

    2016-09-01

    Automated glycan assembly (AGA) has advanced from a concept to a commercial technology that rapidly provides access to diverse oligosaccharide chains as long as 30-mers. To date, AGA was mainly employed to incorporate trans-glycosidic linkages, where C2 participating protecting groups ensure stereoselective couplings. Stereocontrol during the installation of cis-glycosidic linkages cannot rely on C2-participation and anomeric mixtures are typically formed. Here, we demonstrate that oligosaccharides containing multiple cis-glycosidic linkages can be prepared efficiently by AGA using monosaccharide building blocks equipped with remote participating protecting groups. The concept is illustrated by the automated syntheses of biologically relevant oligosaccharides bearing various cis-galactosidic and cis-glucosidic linkages. This work provides further proof that AGA facilitates the synthesis of complex oligosaccharides with multiple cis-linkages and other biologically important oligosaccharides.

  3. Milk oligosaccharides: a review

    OpenAIRE

    Oliveira, Diana; Wilbey, R. Andrew; Grandison, A S; Roseiro, Luísa

    2015-01-01

    Milk oligosaccharides (OSs) confer unique health benefits to the neonate. Although human digestive enzymes cannot degrade these sugars, they support specific commensal microbes and act as decoys to prevent the adhesion of pathogenic micro-organisms to gastrointestinal cells. The limited availability of human milk oligosaccharides (HMOs) impedes research into these molecules and their potential applications in functional food formulations. Recent studies show that complex OSs with fucose and N...

  4. Production of levansucrase from Bacillus subtilis NRC 33a and enzymic synthesis of levan and Fructo-Oligosaccharides.

    Science.gov (United States)

    Abdel-Fattah, Ahmed F; Mahmoud, Doaa A R; Esawy, Mona A T

    2005-12-01

    Bacillus subtilis NRC 33a was able to produce both inducible and constitutive extracellular levansucrase, respectively, using sucrose and glucose as carbon source. The optimal production of the levansucrase was at 30 degrees C. The effect of different nitrogen sources showed that baker's yeast with 2% concentration gave the highest levansucrase activity. Addition of 0.15 g/L MgSO(4) was the most favorable for levansucrase production. The enzymic synthesis of levan was studied using 60% acetone fraction. The results indicated that high enzyme concentrations produced increasing amounts of levan, and hence conversion of fructose to levan reached 84% using 1,000 microg/ml enzyme protein. Sucrose concentration was the most effective factor controlling the molecular weight of the synthesized levan. The conversion of fructose to levan was maximal at 30 degrees C. The time of reaction clearly affected the conversion of fructose to levan, which reached its maximum productivity at 18 hours (92%). Identification of levan indicated that fructose was the building unit of levan. PMID:16328628

  5. Chemoselective single-site Earth-abundant metal catalysts at metal–organic framework nodes

    Science.gov (United States)

    Manna, Kuntal; Ji, Pengfei; Lin, Zekai; Greene, Francis X.; Urban, Ania; Thacker, Nathan C.; Lin, Wenbin

    2016-01-01

    Earth-abundant metal catalysts are critically needed for sustainable chemical synthesis. Here we report a simple, cheap and effective strategy of producing novel earth-abundant metal catalysts at metal–organic framework (MOF) nodes for broad-scope organic transformations. The straightforward metalation of MOF secondary building units (SBUs) with cobalt and iron salts affords highly active and reusable single-site solid catalysts for a range of organic reactions, including chemoselective borylation, silylation and amination of benzylic C–H bonds, as well as hydrogenation and hydroboration of alkenes and ketones. Our structural, spectroscopic and kinetic studies suggest that chemoselective organic transformations occur on site-isolated, electron-deficient and coordinatively unsaturated metal centres at the SBUs via σ-bond metathesis pathways and as a result of the steric environment around the catalytic site. MOFs thus provide a novel platform for the development of highly active and affordable base metal catalysts for the sustainable synthesis of fine chemicals. PMID:27574182

  6. Synthesis of D-[U-{sup 13}C]Glucal, D-[U-{sup 13}C] Galactal, and L-[U-{sup 13}C]Fucose for NMR structure studies of oligosaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Wu, R.; Unkefer, C.J.; Silks, L.A. III [Los Alamos National Lab., NM (United States)

    1996-12-31

    The role of carbohydrates is well recognized in a variety of important biological phenomena such as cell surface recognition. Recent advances in carbohydrate chemistry, including the development of solid phase synthesis methods, have helped to provide significant quantities of material by offering general protocols for synthesis of well-defined, pure material. However, the study of the solution structure of oligosaccharides by nuclear magnetic resonance techniques have been hampered by the lack of enriched {sup 13}C material. In an effort to help alleviate this situation, we have been interested in the construction of the title compounds from a single economical carbon source, D-[U-{sup 13}C]glucose. Details of the syntheses will be provided.

  7. (Pseudoamide-linked oligosaccharide mimetics: molecular recognition and supramolecular properties

    Directory of Open Access Journals (Sweden)

    José L. Jiménez Blanco

    2010-02-01

    Full Text Available Oligosaccharides are currently recognised as having functions that influence the entire spectrum of cell activities. However, a distinct disadvantage of naturally occurring oligosaccharides is their metabolic instability in biological systems. Therefore, much effort has been spent in the past two decades on the development of feasible routes to carbohydrate mimetics which can compete with their O-glycosidic counterparts in cell surface adhesion, inhibit carbohydrate processing enzymes, and interfere in the biosynthesis of specific cell surface carbohydrates. Such oligosaccharide mimetics are potential therapeutic agents against HIV and other infections, against cancer, diabetes and other metabolic diseases. An efficient strategy to access this type of compounds is the replacement of the glycosidic linkage by amide or pseudoamide functions such as thiourea, urea and guanidine. In this review we summarise the advances over the last decade in the synthesis of oligosaccharide mimetics that possess amide and pseudoamide linkages, as well as studies focussing on their supramolecular and recognition properties.

  8. Acetic acid assisted cobalt methanesulfonate catalysed chemoselective diacetylation of aldehydes

    Institute of Scientific and Technical Information of China (English)

    Min Wang; Zhi Guo Song; Hong Gong; Heng Jiang

    2008-01-01

    Cobalt methanesulfonate in combination with acetic acid catalysed the chemoselective diacetylation of aldehyde with acetic anhydride at room temperature under solvent free conditions. After reaction, cobalt methanesulfonate can be easily recovered and mused many times. The reaction was mild and efficient with good to high yields.

  9. Pd-Catalyzed Intramolecular Heck Reaction, C(sp(2))-H Activation, 1,4-Pd Migration, and Aminopalladation: Chemoselective Synthesis of Dihydroindeno[1,2,3-kl]acridines and 3-Arylindoles.

    Science.gov (United States)

    Gu, Zheng-Yang; Liu, Cheng-Guo; Wang, Shun-Yi; Ji, Shun-Jun

    2016-05-20

    Palladium-catalyzed intramolecular Heck reaction and aminopalladation of N-(2-(1-phenylvinyl)phenyl)aniline for the efficient synthesis of dihydroindeno[1,2,3-kl]acridines and 3-arylindoles via tuning of the phosphine ligands and solvents under two optimized conditions are reported. The reaction follows a 1,4-Pd migration, aminopalladation, C(sp(2))-H activation, as well as five- and six-membered-ring fusion to form different products. The dihydroindeno[1,2,3-kl]acridine derivatives showed higher triplet energy (ET) levels than common blue phosphorescent dopant and may serve as good host candidates for blue triplet emitters. PMID:27137482

  10. Oligosaccharides in Food and Agriculture

    Science.gov (United States)

    Collins, Michelle E.; Rastall, Robert A.

    Oligosaccharides are an integral part of the daily diet for humans and animals. They are primarily used for their nutritional properties, however they are currently receiving much attention due to their physiological effect on the microflora of the gastrointestinal tract. Galacto-oligosaccharides and the fructan-type oligosaccharides, namely FOS and inulin are well established as beneficial to the host and are classified as prebiotic based on data from clinical studies. These compounds dominate this sector of the market, although there are oligosaccharides emerging which have produced very interesting in vitro results in terms of prebiotic status and human trials are required to strengthen the claim. Such compounds include pectic oligosaccharides, gluco-oligosaccharides, gentio-oligosaccharides, kojio-oligosaccharides, and alternan oligosaccharides. The raw materials for production of these prebiotic compounds are derived from natural sources such as plants but also from by products of the food processing industry. In addition to being prebiotic these compounds can be incorporated into foodstuffs due to the physiochemical properties they possess.

  11. Structural Characterisation by ESI-MS of Feruloylated Arabino-oligosaccharides Synthesised by Chemoenzymatic Esterification

    Directory of Open Access Journals (Sweden)

    Paul Christakopoulos

    2007-07-01

    Full Text Available The chemoenzymatic synthesis of feruloylated arabino-oligosaccharides has been achieved, using a feruloyl esterase type C from Sporotrichum thermophile (StFaeC.The structure of the feruloylated products was confirmed by ESI-MSn.

  12. Enzymatic synthesis of β-xylosyl-oligosaccharides by transxylosylation using two beta-xylosidases of glycoside hydrolase family 3 from Aspergillus nidulans FGSC A4

    DEFF Research Database (Denmark)

    Dilokpimol, Adiphol; Nakai, Hiroyuki; Gotfredsen, Charlotte Held;

    2011-01-01

    alcohols as acceptors 18 different p-xylosyl-oligosaccharides were synthesised in 2-36% (BxlA) and 6-66% (BxlB) yields by transxylosylation. BxlA utilised the monosaccharides D-mannose, D-lyxose, D-talose, D-xylose, D-arabinose, L-fucose, D-glucose, D-galactose and D-fructose as acceptors, whereas Bxl......B used the same except for D-lyxose, D-arabinose and L-fucose. BxlB transxylosylated the disaccharides xylobiose, lactulose, sucrose, lactose and turanose in upto 35% yield, while BxlA gave inferior yields on these acceptors. The regioselectivity was acceptor dependent and primarily involved beta-1...

  13. Enzymatic synthesis of novel oligosaccharides from N-acetylsucrosamine and melibiose using Aspergillus niger α-galactosidase, and properties of the products.

    Science.gov (United States)

    Sakaki, Yohei; Tashiro, Mitsuru; Katou, Moe; Sakuma, Chiseko; Hirano, Takako; Hakamata, Wataru; Nishio, Toshiyuki

    2016-09-01

    Two kinds of oligosaccharides, N-acetylraffinosamine (RafNAc) and N-acetylplanteosamine (PlaNAc), were synthesized from N-acetylsucrosamine and melibiose using the transgalactosylation activity of Aspergillus niger α-galactosidase. RafNAc and PlaNAc are novel trisaccharides in which d-glucopyranose residues in raffinose (Raf) and planteose are replaced with N-acetyl-d-glucosamine. These trisaccharides were more stable in acidic solution than Raf. RafNAc was hydrolyzed more rapidly than Raf by α-galactosidase of green coffee bean. In contrast, RafNAc was not hydrolyzed by Saccharomyces cerevisiae invertase, although Raf was hydrolyzed well by this enzyme. These results indicate that the physicochemical properties and steric structure of RafNAc differ considerably from those of Raf. PMID:27254139

  14. C-Glycosyl Analogs of Oligosaccharides

    Science.gov (United States)

    Vauzeilles, Boris; Urban, Dominique; Doisneau, Gilles; Beau, Jean-Marie

    This chapter covers the synthesis of a large collection of "C-oligosaccharides ", synthetic analogs of naturally occurring oligosaccharides in which a carbon atom replaces the anomeric, interglycosidic oxygen atom. These non-natural constructs are stable to chemical and enzymatic degradation, and are primarily devised to probe carbohydrate-based biological processes. These mainly target carbohydrate-protein interactions such as the modulation of glycoenzyme (glycosylhydrolases and transferases) activities or the design of ligands for lectin Carbohydrate Recognition Domains. The discussion is based on the key carbon-carbon bond assembling steps on carbohydrate templates: ionic (anionic and cationic chemistries, sigmatropic rearrangements) or radical assemblage, and olefin metathesis. Synthetic schemes in which at least one of the monosaccharide units is constructed by total synthesis or by cyclization of acyclic chiral chains are presented separately in a "partial de novo synthesis" section. The review also provides comments, when they are known, on the conformational and binding properties of these synthetic analogs, as well as their biological behavior when tested.

  15. Sucrose and Related Oligosaccharides

    Science.gov (United States)

    Eggleston, Gillian

    Sucrose (α-D-glucopyranosyl-(1↔2)-β-D-fructofuranoside) is the most common low-molecular-weight sugar found in the plant kingdom. It is ubiquitously known as common table sugar and primarily produced industrially from sugarcane (Saccharum officinarum) and sugar beet (Beta vulgaris); the basics of the industrial manufacture of sucrose are outlined in this chapter. Commercial sucrose has a very high purity (> 99.9%) making it one of the purest organic substances produced on an industrial scale. Value-addition to sucrose via chemical and biotechnological reactions is becoming more important for the diversification of the sugar industry to maintain the industries' competitiveness in a world increasingly turning to a bio-based economy. The basis for the chemical reactivity of sucrose is the eight hydroxyl groups present on the molecule, although, sucrose chemical reactivity is regarded as difficult. Increasing use of enzymatic biotechnological techniques to derivatize sucrose is expected, to add special functionalities to sucrose products like biodegradability, biocompatibility, and non-toxicity. Analysis of sucrose by colorimetric, enzymatic, oxidation-reduction and chromatography methods are discussed. Oligosaccharides related to sucrose are outlined in detail and include sucrose-based plant, honey and in vitro oligosaccharides.

  16. Synthesis and solution conformation of the type 2 blood group oligosaccharide αLFuc(1 → 2)βDGal(1 → 4)βDGlcNAc

    International Nuclear Information System (INIS)

    Partially purified glycosyltransferases and chemically synthesized sugar nucleotides have been used to prepare a number of oligosaccharides related to the type 2 (human) blood group (H) substance. The following oligosaccharides were prepared and purified by ion-exchange and gel-filtration chromatography: αLFuc(1→2)-βDGal(1→4)βDGlcNAc-hexanolamine, αLFuc(1→2)βD[1-13C]Gal(1→4)βDGlcNAc-hexanolamine, αL[1-13C]Fuc(1→2)βD[1-13C]Gal(1→4)βDGlcNAc-hexanolamine, αL[1-13C]-Fuc(1→2)βD[1-13C]Gal(1→4)βDGlcNAc, αLFuc(1→2)βD-[1-13C]Gal(1→4)βDGlcNAc, αL[1-13C]Fuc(1→2)βD[1-13C]-Gal(1→4)βDGlc, αLFuc(1→2)βD[1-13C]Gal-hexanolamine, αL[1-13C]Fuc(1→2)βD[1-13C]Gal-ethanol, αLFuc(1→2)βD-[1-13C]Gal-ethanol, αL[1-13C]Fuc(1→2)βDGal-ethanol and αLFuc(1→2)βD[2-13C]Gal-ethanol. Specific 13C enrichment and comparison with 13C-enriched model compounds allowed unambiguous assignment of 13C resonances. Fucosylation at O2 of βDGal(1→4)βDGlcNAc-hexanolamine caused a 5.6 ppm downfield shift of the C2 resonance of Gal. Fucosylation of the disaccharide βDGal(1→4)DGlcNAc resulted in a similar pattern of chemical shift changes. Interresidue coupling constants (3J/sub C1-C1'/ approx. = 1.5 Hz observed as line broadening, 3J/sub H1-C2'/ approx. = 3.2 Hz, 3J/sub C1'-C3''/ approx. = 0 Hz, 3J/sub C1'-C5''/ approx. = 1.0 Hz observed as line broadening, and 2J/sub C1'-C4''/ approx. = 1.5 Hz) in the enriched oligosaccharides allowed estimation of the most abundant conformer for the Phi and Psi torsion angles in the βDGal(1→4)GlcNAc (Phi' approx. = 600 and Psi' approx. = 150) and αLFuc(1→2)DGal(Phi approx. = 550 and Psi approx. = 00) glycosidic linkages of the trisaccharide

  17. Two β-galactosidases from the human isolate Bifidobacterium breve DSM 20213: molecular cloning and expression, biochemical characterization and synthesis of galacto-oligosaccharides.

    Science.gov (United States)

    Arreola, Sheryl Lozel; Intanon, Montira; Suljic, Jasmina; Kittl, Roman; Pham, Ngoc Hung; Kosma, Paul; Haltrich, Dietmar; Nguyen, Thu-Ha

    2014-01-01

    Two β-galactosidases, β-gal I and β-gal II, from Bifidobacterium breve DSM 20213, which was isolated from the intestine of an infant, were overexpressed in Escherichia coli with co-expression of the chaperones GroEL/GroES, purified to electrophoretic homogeneity and biochemically characterized. Both β-gal I and β-gal II belong to glycoside hydrolase family 2 and are homodimers with native molecular masses of 220 and 211 kDa, respectively. The optimum pH and temperature for hydrolysis of the two substrates o-nitrophenyl-β-D-galactopyranoside (oNPG) and lactose were determined at pH 7.0 and 50°C for β-gal I, and at pH 6.5 and 55°C for β-gal II, respectively. The kcat/Km values for oNPG and lactose hydrolysis are 722 and 7.4 mM-1s-1 for β-gal I, and 543 and 25 mM-1s-1 for β-gal II. Both β-gal I and β-gal II are only moderately inhibited by their reaction products D-galactose and D-glucose. Both enzymes were found to be very well suited for the production of galacto-oligosaccharides with total GOS yields of 33% and 44% of total sugars obtained with β-gal I and β-gal II, respectively. The predominant transgalactosylation products are β-D-Galp-(1→6)-D-Glc (allolactose) and β-D-Galp-(1→3)-D-Lac, accounting together for more than 75% and 65% of the GOS formed by transgalactosylation by β-gal I and β-gal II, respectively, indicating that both enzymes have a propensity to synthesize β-(1→6) and β-(1→3)-linked GOS. The resulting GOS mixtures contained relatively high fractions of allolactose, which results from the fact that glucose is a far better acceptor for galactosyl transfer than galactose and lactose, and intramolecular transgalactosylation contributes significantly to the formation of this disaccharide. PMID:25089712

  18. Two β-galactosidases from the human isolate Bifidobacterium breve DSM 20213: molecular cloning and expression, biochemical characterization and synthesis of galacto-oligosaccharides.

    Directory of Open Access Journals (Sweden)

    Sheryl Lozel Arreola

    Full Text Available Two β-galactosidases, β-gal I and β-gal II, from Bifidobacterium breve DSM 20213, which was isolated from the intestine of an infant, were overexpressed in Escherichia coli with co-expression of the chaperones GroEL/GroES, purified to electrophoretic homogeneity and biochemically characterized. Both β-gal I and β-gal II belong to glycoside hydrolase family 2 and are homodimers with native molecular masses of 220 and 211 kDa, respectively. The optimum pH and temperature for hydrolysis of the two substrates o-nitrophenyl-β-D-galactopyranoside (oNPG and lactose were determined at pH 7.0 and 50°C for β-gal I, and at pH 6.5 and 55°C for β-gal II, respectively. The kcat/Km values for oNPG and lactose hydrolysis are 722 and 7.4 mM-1s-1 for β-gal I, and 543 and 25 mM-1s-1 for β-gal II. Both β-gal I and β-gal II are only moderately inhibited by their reaction products D-galactose and D-glucose. Both enzymes were found to be very well suited for the production of galacto-oligosaccharides with total GOS yields of 33% and 44% of total sugars obtained with β-gal I and β-gal II, respectively. The predominant transgalactosylation products are β-D-Galp-(1→6-D-Glc (allolactose and β-D-Galp-(1→3-D-Lac, accounting together for more than 75% and 65% of the GOS formed by transgalactosylation by β-gal I and β-gal II, respectively, indicating that both enzymes have a propensity to synthesize β-(1→6 and β-(1→3-linked GOS. The resulting GOS mixtures contained relatively high fractions of allolactose, which results from the fact that glucose is a far better acceptor for galactosyl transfer than galactose and lactose, and intramolecular transgalactosylation contributes significantly to the formation of this disaccharide.

  19. Synthesis of highly anti-HIV active sulfated poly- and oligo-saccharides and analysis of their action mechanisms by NMR [nuclear magnetic resonance] spectroscopy

    International Nuclear Information System (INIS)

    We have been synthesizing sulfated polysaccharides and oligosaccharides with highly anti-HIV (human immunodeficiency virus) activities. It has been known that sulfated polysaccharides such as dextran sulfate and pentosan polysulfate have biological activities such as anticoagulant activity and recently anti-HIV activity. Curdlan sulfate having 1,3-β-linked glucan backbone had high anti-HIV activity but low anticoagulant activity. Phase I/II test for the curdlan sulfate as an AIDS (acquired immunodeficiency syndrome) drug was carried out in the United States. In this study, regioselectivity sulfatec curdlan sulfates were prepared in order to study effects of sulfate groups and conformation of curdlan sulfates. In addition, action mechanisms of curdlan sulfate as anti-AIDS drug and of heparin as an anticoagulant were examined by means of NMR spectroscopy. 1. Structure dependence of anti-HIV and anticoagulant activities of sulfated polysaccharides. Curdlan with M n 9000 was regioselectively sulfated on its hydroxyl groups at 6, 4, and 2 positions. Those were a curdlan sulfate 62S in which 100% of 6-OH, and about 50% of 2-OH was sulfated, a curdlan sulfate 42S in which 4- and 2-OH's were sulfated, and a curdlan sulfate in which 6, 4, and 2-OH's were partially sulfated. All curdlan sulfates had very high anti-HIV activities exhibited by the drug concentration of 50% inhibition of infection, i.e., EC50 of 0.04 - 0.25 μg/mL. However, there was almost no difference in the activity among the samples. Therefore, it was revealed that the degree of sulfation and putative conformation of the curdlan sulfates but not the position of sulfate groups have large effects on the anti-HIV activity. On the other hand, the anticoagulant activity increased with increasing molecular weight of the curdlan sulfates. As a result, it is assumed that the size of reaction sites of the virus protein reacting with curdlan sulfate is different from that of the proteins related to anticoagulant. 2

  20. Chemoselective Reactivity of Bifunctional Cyclooctynes on Si(001)

    CERN Document Server

    Reutzel, Marcel; Lipponer, Marcus A; Länger, Christian; Höfer, Ulrich; Koert, Ulrich; Dürr, Michael

    2016-01-01

    Controlled organic functionalization of silicon surfaces as integral part of semiconductor technology offers new perspectives for a wide range of applications. The high reactivity of the silicon dangling bonds, however, presents a major hindrance for the first basic reaction step of such a functionalization, i.e., the chemoselective attachment of bifunctional organic molecules on the pristine silicon surface. We overcome this problem by employing cyclooctyne as the major building block of our strategy. Functionalized cyclooctynes are shown to react on Si(001) selectively via the strained cyclooctyne triple bond while leaving the side groups intact. The achieved selectivity originates from the distinctly different adsorption dynamics of the separate functionalities: A direct adsorption pathway is demonstrated for cyclooctyne as opposed to the vast majority of other organic functional groups. The latter ones react on Si(001) via a metastable intermediate which makes them effectively unreactive in competition wi...

  1. Alkene Chemoselectivity in Ruthenium-Catalyzed Z-Selective Olefin Metathesis

    Science.gov (United States)

    Cannon, Jeffrey S.

    2013-01-01

    Chelated ruthenium catalysts have achieved highly chemoselective olefin metathesis reactions. Terminal and internal Z olefins were selectively reacted in the presence of internal E olefins. Products were produced in good yield and high stereoselectivity for formation of a new Z olefin. No products of metathesis with the internal E olefin were observed. Chemoselectivity for terminal olefins was also observed over both sterically hindered and electronically deactivated alkenes. PMID:23832646

  2. Extraction of hemicellulosic oligosaccharides from spruce using microwave oven or steam treatment.

    Science.gov (United States)

    Palm, Magnus; Zacchi, Guido

    2003-01-01

    This paper describes the extraction of hemicellulosic oligosaccharides from spruce, using microwave or steam treatment that can be used for the production of polymers, replacing fossil-based polymers, e.g., hydrogels. The highest yield of oligosaccharides, measured as mannan, was 70% obtained with treatment in the microwave oven at 200 degrees C for 5 min. The amount of oligosaccharides extracted was 12.5 g per 100 g of dry wood. The molecular weights of some selected samples were analyzed using fast protein liquid chromatography and size exclusion chromatography and time-of-flight matrix-assisted laser desorption ionization. Recovered oligosaccharides following steam treatment at 200 degrees C for 2 min had a mean molecular weight of 3400 g/mol with a maximum weight of 12000 g/mol. Higher severity, i.e., increased temperature (>200 degrees C) and residence time, resulted in lower mean molecular weights and yield. Oligosaccharides with higher mean molecular weights were obtained at lower severity, but the yield was considerably lower. The feasibility of using the extracted hemicellulosic oligosaccharides from spruce for the synthesis of hydrogels was demonstrated.

  3. Galacto-oligosaccharides exert a protective effect against heat stress in a Caco-2 cell model

    NARCIS (Netherlands)

    Varasteh, Soheil; Braber, Saskia; Garssen, Johan; Fink-Gremmels, Johanna

    2015-01-01

    Thermal stress can evoke a stress response and enhance the synthesis of heat shock proteins, while gut barrier dysfunction is considered as an important adverse effect of thermal stress. Considering the previously described effects of galacto-oligosaccharides, nowadays mainly used in infant formulas

  4. Development of a Rhodium(II)-Catalyzed Chemoselective C(sp(3) )-H Oxygenation.

    Science.gov (United States)

    Lin, Yun; Zhu, Lei; Lan, Yu; Rao, Yu

    2015-10-12

    We report the first example of Rh(II) -catalyzed chemoselective double C(sp(3) )-H oxygenation, which can directly transform various toluene derivatives into highly valuable aromatic aldehydes with great chemoselectivity and practicality. The critical combination of catalyst Rh(OAc)2 , oxidant Selectfluor, and solvents of TFA/TFAA promises the successful delivery of the oxidation with satisfactory yields. A possible mechanism involving a unique carbene-Rh complex is proposed, and has been supported by both experiments and theoretical calculations.

  5. A calculation of all possible oligosaccharide isomers both branched and linear yields 1.05 x 10(12) structures for a reducing hexasaccharide: the Isomer Barrier to development of single-method saccharide sequencing or synthesis systems.

    Science.gov (United States)

    Laine, R A

    1994-12-01

    The number of all possible linear and branched isomers of a hexasaccharide was calculated and found to be > 1.05 x 10(12). This large number defines the Isomer Barrier, a persistent technological barrier to the development of a single analytical method for the absolute characterization of carbohydrates, regardless of sample quantity. Because of this isomer barrier, no single method can be employed to determine complete oligosaccharide structure in 100 nmol amounts with the same assurance that can be achieved for 100 pmol amounts with single-procedure Edman peptide or Sanger DNA sequencing methods. Difficulties in the development of facile synthetic schemes for oligosaccharides are also explained by this large number. No current method of chemical or physical analysis has the resolution necessary to distinguish among 10(12) structures having the same mass. Therefore the 'characterization' of a middle-weight oligosaccharide solely by NMR or mass spectrometry necessarily contains a very large margin of error. Greater uncertainty accompanies results performed solely by sequential enzyme degradation followed by gel-permeation chromatography or electrophoresis, as touted by some commercial advertisements. Much of the literature which uses these single methods to 'characterize' complex carbohydrates is, therefore, in question, and journals should beware of publishing structural characterizations unless the authors reveal all alternate possible structures which could result from their analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Automated glycan assembly of xyloglucan oligosaccharides.

    Science.gov (United States)

    Dallabernardina, Pietro; Schuhmacher, Frank; Seeberger, Peter H; Pfrengle, Fabian

    2016-01-01

    We report the automated glycan assembly of oligosaccharide fragments related to the hemicellulose xyloglucan (XG). Iterative addition of monosaccharide and disaccharide building blocks to a solid support provided seven cellulose and xyloglucan fragments including XXGG- and XXXG-type oligosaccharides. PMID:26553949

  7. Chemoselective Oxidation of Bio-Glycerol with Nano-Sized Metal Catalysts

    DEFF Research Database (Denmark)

    Li, Hu; Kotni, Ramakrishna; Zhang, Qiuyun;

    2015-01-01

    selectively oxidize glycerol and yield products with good selectivity is the use of nano-sized metal particles as heterogeneous catalysts. In this short review, recent developments in chemoselective oxidation of glycerol to specific products over nano-sized metal catalysts are described. Attention is drawn to...

  8. Palladium-Catalyzed Chemoselective and Biocompatible Functionalization of Cysteine-Containing Molecules at Room Temperature.

    Science.gov (United States)

    Al-Shuaeeb, Riyadh Ahmed Atto; Kolodych, Sergii; Koniev, Oleksandr; Delacroix, Sébastien; Erb, Stéphane; Nicolaÿ, Stéphanie; Cintrat, Jean-Christophe; Brion, Jean-Daniel; Cianférani, Sarah; Alami, Mouâd; Wagner, Alain; Messaoudi, Samir

    2016-08-01

    The third generation of aminobiphenyl palladacycle pre-catalyst "G3-Xantphos" enables functionalization of peptides containing cysteine in high yields. The conjugation (bioconjugation) occurs chemoselectively at room temperature under biocompatible conditions. Extension of the method to protein functionalization allows selective bioconjugation of the trastuzumab antibody. PMID:27362372

  9. Samarium-promoted Chemoselective Reduction of Aromatic Nitro Compounds in Ionic Liquid

    Institute of Scientific and Technical Information of China (English)

    ZHENG,Xing-Liang(郑兴良); ZHANG,Yong-Min(张永敏)

    2002-01-01

    The differently substituted aromatic nitro compoumds were chemoselectively reduced by Sm/HOAc system in an ionic liquid medium to afford aromatic amines. Under these conditions the other substituents, such as -X, -CHO, -COOH, -CN,-NHTos and - alkyl, remained intact. The notable advantagesofthis reaction areits mild conditions, simple operaton,short reaction time, high yields and easy recycling of ionic liquid.

  10. Elucidation of the regio- and chemoselectivity of enzymatic allylic oxidations with Pleurotus sapidus – conversion of selected spirocyclic terpenoids and computational analysis

    Directory of Open Access Journals (Sweden)

    Verena Weidmann

    2013-10-01

    Full Text Available Allylic oxidations of olefins to enones allow the efficient synthesis of value-added products from simple olefinic precursors like terpenes or terpenoids. Biocatalytic variants have a large potential for industrial applications, particularly in the pharmaceutical and food industry. Herein we report efficient biocatalytic allylic oxidations of spirocyclic terpenoids by a lyophilisate of the edible fungus Pleurotus sapidus. This ‘’mushroom catalysis’’ is operationally simple and allows the conversion of various unsaturated spirocyclic terpenoids. A number of new spirocyclic enones have thus been obtained with good regio- and chemoselectivity and chiral separation protocols for enantiomeric mixtures have been developed. The oxidations follow a radical mechanism and the regioselectivity of the reaction is mainly determined by bond-dissociation energies of the available allylic CH-bonds and steric accessibility of the oxidation site.

  11. Heterogenized Bimetallic Pd-Pt-Fe3O4 Nanoflakes as Extremely Robust, Magnetically Recyclable Catalysts for Chemoselective Nitroarene Reduction.

    Science.gov (United States)

    Byun, Sangmoon; Song, Yeami; Kim, B Moon

    2016-06-15

    A very simple synthesis of bimetallic Pd-Pt-Fe3O4 nanoflake-shaped alloy nanoparticles (NPs) for cascade catalytic reactions such as dehydrogenation of ammonia-borane (AB) followed by the reduction of nitro compounds (R-NO2) to anilines or alkylamines (R-NH2) in methanol at ambient temperature is described. The Pd-Pt-Fe3O4 NPs were easily prepared via a solution phase hydrothermal method involving the simple one-pot coreduction of potassium tetrachloroplatinate (II) and palladium chloride (II) in polyvinylpyrrolidone with subsequent deposition on commercially available Fe3O4 NPs. The bimetallic Pd-Pt alloy NPs decorated on Fe3O4 NPs provide a unique synergistic effect for the catalysis of cascade dehydrogenation/reduction. Various nitroarene derivatives were reduced to anilines with very specific chemoselectivity in the presence of other reducible functional groups. The bimetallic Pd-Pt-Fe3O4 NPs provide a unique synergistic effect for the catalysis of cascade dehydrogenation/reduction. The nitro reduction proceeded in 5 min with nearly quantitative conversions and yields. Furthermore, the magnetically recyclable nanocatalysts were readily separated using an external magnet and reused up to 250 times without any loss of catalytic activity. A larger scale (10 mmol) reaction was also successfully performed with >99% yield. This efficient, recyclable Pd-Pt-Fe3O4 NPs system can therefore be repetitively utilized for the reduction of various nitro-containing compounds. PMID:27191706

  12. Surface-Functionalized Nanoparticles by Olefin Metathesis: A Chemoselective Approach for In Vivo Characterization of Atherosclerosis Plaque.

    Science.gov (United States)

    Salinas, Beatriz; Ruiz-Cabello, Jesús; Lechuga-Vieco, Ana V; Benito, Marina; Herranz, Fernando

    2015-07-13

    The use of click chemistry reactions for the functionalization of nanoparticles is particularly useful to modify the surface in a well-defined manner and to enhance the targeting properties, thus facilitating clinical translation. Here it is demonstrated that olefin metathesis can be used for the chemoselective functionalization of iron oxide nanoparticles with three different examples. This approach enables, in one step, the synthesis and functionalization of different water-stable magnetite-based particles from oleic acid-coated counterparts. The surface of the nanoparticles was completely characterized showing how the metathesis approach introduces a large number of hydrophilic molecules on their coating layer. As an example of the possible applications of these new nanocomposites, a focus was taken on atherosclerosis plaques. It is also demonstrated how the in vitro properties of one of the probes, particularly its Ca(2+) -binding properties, mediate their final in vivo use; that is, the selective accumulation in atherosclerotic plaques. This opens promising new applications to detect possible microcalcifications associated with plaque vulnerability. The accumulation of the new imaging tracers is demonstrated by in vivo magnetic resonance imaging of carotids and aorta in the ApoE(-/-) mouse model and the results were confirmed by histology.

  13. Chemoselective O-acylation of hydroxyamino acids and amino alcohols under acidic reaction conditions: History, scope and applications

    Directory of Open Access Journals (Sweden)

    Tor E. Kristensen

    2015-04-01

    Full Text Available Amino acids, whether natural, semisynthetic or synthetic, are among the most important and useful chiral building blocks available for organic chemical synthesis. In principle, they can function as inexpensive, chiral and densely functionalized starting materials. On the other hand, the use of amino acid starting materials routinely necessitates protective group chemistry, and in reality, large-scale preparations of even the simplest side-chain derivatives of many amino acids often become annoyingly strenuous due to the necessity of employing protecting groups, on one or more of the amino acid functionalities, during the synthetic sequence. However, in the case of hydroxyamino acids such as hydroxyproline, serine, threonine, tyrosine and 3,4-dihydroxyphenylalanine (DOPA, many O-acyl side-chain derivatives are directly accessible via a particularly expedient and scalable method not commonly applied until recently. Direct acylation of unprotected hydroxyamino acids with acyl halides or carboxylic anhydrides under appropriately acidic reaction conditions renders possible chemoselective O-acylation, furnishing the corresponding side-chain esters directly, on multigram-scale, in a single step, and without chromatographic purification. Assuming a certain degree of stability under acidic reaction conditions, the method is also applicable for a number of related compounds, such as various amino alcohols and the thiol-functional amino acid cysteine. While the basic methodology underlying this approach has been known for decades, it has evolved through recent developments connected to amino acid-derived chiral organocatalysts to become a more widely recognized procedure for large-scale preparation of many useful side-chain derivatives of hydroxyamino acids and related compounds. Such derivatives are useful in peptide chemistry and drug development, as amino acid amphiphiles for asymmetric catalysis, and as amino acid acrylic precursors for preparation of

  14. Raffinose-Series Oligosaccharides in Soybean Products

    Directory of Open Access Journals (Sweden)

    Švejstil R.

    2015-06-01

    Full Text Available Soybean foods forming a substantial part of Asian diet have still more expanded into European diet. Raffinose-series oligosaccharides (RSO are important constituents of soya beans and they can be found also in soybean products. These oligosaccharides can be considered potentially prebiotic for their capability of influencing the composition of the host’s intestinal microbiota. The aim of the present paper was to determine the oligosaccharide content in various soybean products. Enzymatic assay has been used for the determination of oligosaccharides. RSO have been found in all tested samples and their content varied from 0.66 g per 100 g in soybean beverage to 5.59 g per 100 g in first clear soybean flour. Generally, the highest content of RSO has been detected in soybean flour in the average amount of 4.83 g per 100 g. There was no statistically significant difference observed in the amount of oligosaccharides in all four types of soybean flour (P < 0.01. Considerably high amounts of RSO have been found in sweet soybean bars and textured soy protein. Foods as soybean flour and soybean bar ‘Sójový suk’ seem to be effective natural sources of prebiotic oligosaccharides for humans.

  15. Non-Natural Sugar Analogues: Chemical Probes for Metabolic Oligosaccharide Engineering

    Science.gov (United States)

    Aich, Udayanath; Yarema, Kevin J.

    Metabolic oligosaccharide engineering (MOE) is a rapidly growing technology emerging from the field of chemical biology that allows novel chemical functionalities to be biosynthetically installed into the carbohydrates of living cells and animals. Since pioneering efforts to modulate sialic acid display through the use of non-natural N-acetyl-D-mannosamine (ManNAc) analogues were reported 15 years ago, monosaccharide probes have been developed to manipulate N-acetyl-D-galactosamine (GalNAc), N-acetyl-D-glucosamine (GlcNAc), and fucose-containing glycans. The 'first generation' of analogues, comprised of a series of ManNAc derivatives with elongated N-acyl chains, demonstrated pathway permissivity and the ability of this methodology to impinge on biological processes ranging from pathogen binding to gene expression and cell adhesion. Later analogues have incorporated chemical function groups including ketones, azides, thiols, and alkyne not normally found in carbohydrates. These groups serve as 'tags' for the subsequent use of chemoselective ligation reactions to further elaborate the chemical properties of the cell surface and thereby greatly expand the potential of MOE technology to offer control over biological processes.

  16. Comparison of Milk Oligosaccharides Pattern in Colostrum of Different Horse Breeds

    NARCIS (Netherlands)

    Difilippo, E.; Willems, H. A. M.; Vendrig, J. C.; Fink-Gremmels, J.; Gruppen, H.; Schols, H. A.

    2015-01-01

    Colostrum oligosaccharides are known to exhibit prebiotic and immunomodulatory properties. Oligosaccharide composition is species-specific, and equine colostrum has been reported to contain unique oligosaccharides. Therefore, equine oligosaccharides (EMOS) from colostrum from different horse breeds

  17. In vitro synthesis and structural analysis of selected acceptor products of Weissella confusa VTT E-90392 dextransucrase

    OpenAIRE

    Hou, Yaxi

    2014-01-01

    Non-digestible oligosaccharides possess important physicochemical and physiological properties. They have gained great attention because of their potential prebiotic properties. The oligosaccharides have wide food industrial applications as dietary fibers, sweeteners, humectants, and possible weight controlling agents. In this thesis, cloned Weissella confusa VTT E-90392 dextransucrase was used to catalyze the synthesis of oligosaccharides (acceptor products) by acceptor reaction, when su...

  18. Resonant infrared pulsed-laser deposition of a sorbent chemoselective polymer

    DEFF Research Database (Denmark)

    Bubb, D.M.; Horwitz, J.S.; McGill, R.A.;

    2001-01-01

    Fluoropolyol, a sorbent chemoselective polymer, has been deposited as a thin film by resonant infrared pulsed laser deposition using a free electron laser operating at 2.90 mum, a wavelength resonant with the hydroxl stretch. A comparison of the infrared absorbance of the deposited film and start......Fluoropolyol, a sorbent chemoselective polymer, has been deposited as a thin film by resonant infrared pulsed laser deposition using a free electron laser operating at 2.90 mum, a wavelength resonant with the hydroxl stretch. A comparison of the infrared absorbance of the deposited film...... laser deposition using intrinsic vibrational modes may have wide applicability for organic materials. (C) 2001 American Institute of Physics....

  19. Environment friendly chemoselective deprotection of acetonides and cleavage of acetals and ketals in aqueous medium without using any catalyst or organic solvent

    Indian Academy of Sciences (India)

    S Mukherjee; A Sengupta; S C Roy

    2013-11-01

    Highly chemoselective environment friendly deprotection of acetonides and cleavage of acetals and ketones has been achieved by heating in aqueous medium without using any catalyst and organic solvent.

  20. Chemoselective reaction of cyanoacetic acid with benzal-4-acetylanilines and fungitoxicity of products

    Indian Academy of Sciences (India)

    Anjali Sidhu; J R Sharma; Mangat Rai

    2009-07-01

    Cyanoacetic acid reacted chemoselectively with carbon-nitrogen double bond of benzal-4-acetylaniliines, leaving the carbon-oxygen double bond, considered to be more reactive, intact, leading to the formation of mono addition-elimination products rather than bis attack at both the reactive centres, even when the reaction was carried out with two moles of cyanoacetic acid. The product viz. benzalcyanoacetic acid and its derivatives were screened for their fungitoxicity against five pathogenic fungi.

  1. Two-photon fluorescence imaging of intracellular hydrogen peroxide with chemoselective fluorescent probes

    OpenAIRE

    Guo, Hengchang; Aleyasin, Hossein; Howard, Scott S.; Dickinson, Bryan C; Lin, Vivian S.; Haskew-Layton, Renee E.; Xu, Chris; Chen, Yu; Ratan, Rajiv R.

    2013-01-01

    Abstract. We present the application of two-photon fluorescence (TPF) imaging to monitor intracellular hydrogen peroxide (H2O2) production in brain cells. For selective imaging of H2O2 over other reactive oxygen species, we employed small-molecule fluorescent probes that utilize a chemoselective boronate deprotection mechanism. Peroxyfluor-6 acetoxymethyl ester detects global cellular H2O2 and mitochondria peroxy yellow 1 detects mitochondrial H2O2. Two-photon absorption cross sections for th...

  2. Two-photon fluorescence imaging of intracellular hydrogen peroxide with chemoselective fluorescent probes

    OpenAIRE

    Guo, Hengchang; Aleyasin, Hossein; Howard, Scott S.; Dickinson, Bryan C; Lin, Vivian S.; Haskew-Layton, Renee E.; Xu, Chris; Chen, Yu; Ratan, Rajiv R.

    2013-01-01

    Abstract. We present the application of two-photon fluorescence (TPF) imaging to monitor intracellular hydrogen peroxide ( H 2 O 2 ) production in brain cells. For selective imaging of H 2 O 2 over other reactive oxygen species, we employed small-molecule fluorescent probes that utilize a chemoselective boronate deprotection mechanism. Peroxyfluor-6 acetoxymethyl ester detects global cellular H 2 O 2 and mitochondria peroxy yellow 1 detects mitochondrial H 2 O 2 . Two-photon absorption cross ...

  3. Samarium—promoted Chemoselective Reduction of Aromatic Nitro Compounds in Ionic Liquid

    Institute of Scientific and Technical Information of China (English)

    郑兴良; 张永敏; 等

    2002-01-01

    The differently substituted aromatic nitro compounds were chemoselectively reduced by Sm/HOAc system in an ionic liq-uid medium to afford aromatic amines,Under these conditions the other substituents,such as -X,-CHO,-COOH,-CN,-NHTos and -alkyl,remained intact,the notable advan-tages of this reaction are its mild conditions ,simple operation,short reaction time,high yields and easy recycling of ionic liquid.

  4. Chemoselective hydrogenation of carbonyl compounds and acceptorless dehydrogenative coupling of alcohols.

    Science.gov (United States)

    Spasyuk, Denis; Vicent, Cristian; Gusev, Dmitry G

    2015-03-25

    OsHCl(CO)[κ(3)-PyCH2NHC2H4NHPtBu2] is the first efficient catalyst for chemoselective reduction of challenging unsaturated esters to enols and for acceptorless coupling of amines with MeOH and EtOH affording formamides and acetamides. The NMR, ESI-MS, and DFT data indicate a mechanism proceeding in the metal coordination sphere and producing no free organic intermediates. PMID:25741992

  5. Engineering the glucansucrase GTFR enzyme reaction and glycosidic bond specificity : Toward tailor-made polymer and oligosaccharide products

    NARCIS (Netherlands)

    Hellmuth, Hendrik; Wittrock, Sabine; Kralj, Slavko; Dijkhuizen, Lubbert; Hofer, Bernd; Seibel, Juergen; Seibel, Jürgen

    2008-01-01

    Two long-standing questions about glucansucrases (EC 2.4.1.5) are how they control oligosaccharide versus polysaccharide synthesis and how they direct their glycosidic linkage specificity. This information is required for the production of tailor-made saccharides. Mutagenesis promises to be an effec

  6. Chemoselective tarantula toxins report voltage activation of wild-type ion channels in live cells.

    Science.gov (United States)

    Tilley, Drew C; Eum, Kenneth S; Fletcher-Taylor, Sebastian; Austin, Daniel C; Dupré, Christophe; Patrón, Lilian A; Garcia, Rita L; Lam, Kit; Yarov-Yarovoy, Vladimir; Cohen, Bruce E; Sack, Jon T

    2014-11-01

    Electrically excitable cells, such as neurons, exhibit tremendous diversity in their firing patterns, a consequence of the complex collection of ion channels present in any specific cell. Although numerous methods are capable of measuring cellular electrical signals, understanding which types of ion channels give rise to these signals remains a significant challenge. Here, we describe exogenous probes which use a novel mechanism to report activity of voltage-gated channels. We have synthesized chemoselective derivatives of the tarantula toxin guangxitoxin-1E (GxTX), an inhibitory cystine knot peptide that binds selectively to Kv2-type voltage gated potassium channels. We find that voltage activation of Kv2.1 channels triggers GxTX dissociation, and thus GxTX binding dynamically marks Kv2 activation. We identify GxTX residues that can be replaced by thiol- or alkyne-bearing amino acids, without disrupting toxin folding or activity, and chemoselectively ligate fluorophores or affinity probes to these sites. We find that GxTX-fluorophore conjugates colocalize with Kv2.1 clusters in live cells and are released from channels activated by voltage stimuli. Kv2.1 activation can be detected with concentrations of probe that have a trivial impact on cellular currents. Chemoselective GxTX mutants conjugated to dendrimeric beads likewise bind live cells expressing Kv2.1, and the beads are released by channel activation. These optical sensors of conformational change are prototype probes that can indicate when ion channels contribute to electrical signaling. PMID:25331865

  7. Synthesis and Characterization of Chitosan Oligosaccharide-graft-Acrylic Acid Biodegradable Crosslinker%丙烯酸接枝壳寡糖生物可降解交联剂的合成与表征

    Institute of Scientific and Technical Information of China (English)

    苏宇佳; 赵骞; 孙建中

    2012-01-01

    在1-乙基-3-(3-二甲氨丙基)碳化二亚胺盐酸盐(EDC)和N-羟基琥珀酰亚胺(NHS)催化作用下,采用水溶性的壳寡糖(CSO)与丙烯酸(AA)发生N-酰化反应,制备出一种新型水溶性可降解水凝胶交联剂——丙烯酸接枝壳寡糖(CSO-g-AA).用CSO-g-AA与丙烯酰胺单体共聚制备了聚丙烯酰胺水凝胶.该水凝胶可在蜗牛酶作用下降解为水溶性直链聚丙烯酰胺.采用1H-NMR、红外吸收光谱法对CSO-g-AA结构进行表征,用溴酸钾-溴化钾滴定法定量分析了CSO-g-AA中不饱和双键的含量.结果表明:该交联剂中不饱和双键的接枝率约为4%,在适当的温度、pH值和酶浓度下水凝胶经72 h完全降解.%A new water soluble and biodegradable crosslinker of chitosan oligosaccharide-graft-acrylic acid (CSO-g-AA) was synthesized through the acrylyl reaction of amino groups in the chitosan oligosaccharide (CSO) chains with acrylic acid (AA) catalyzed by 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimidehydro-chloride (EDC) and N-hydroxysuccinimide (NHS). Polyacrylamide (PAM) hydrogels were prepared by copolymerization of acrylamide and CSO-g-AA. CSO-g-AA was structurally characterized by Fourier transform infrared spectroscopy (FT-IR) and H-1 nuclear magnetic resonance (1H-NMR) spectroscopy. The content of unsaturated double bond in CSO-g-AA was quantitatively analysed by titration analysis using potassium bromate (KBrO) and potassium bromide (KBr). The results show that the grafting ratio of unsaturated double bond in CSO-g-AA is about 4%. At a proper temperature, pH value and concentration of enzyme, the PAM hydrogels can be degraded to water soluble polyacrylamide chains in 72 h under the catalysis of snailase.

  8. Combinatorial solid-phase synthesis of hapalosin mimetics

    DEFF Research Database (Denmark)

    Olsen, Jacob A.; Jensen, Knud J.; Nielsen, John

    2000-01-01

    The solid-phase synthesis of a small library of mimetics of the cyclic depsipeptide hapalosin is described. 3-Amino-4-hydroxy-5-nitrobenzoic acid was anchored through the anilino moiety to a backbone amide linker (BAL) handle support. Using chemoselective reactions and without the need for...

  9. A Novel Regiospecific Synthesis of 1-Chloro-2-arylcyclohexenes

    Directory of Open Access Journals (Sweden)

    Lokesh Krishnappa

    2014-01-01

    Full Text Available An efficient high yielding chemoselective synthesis of eleven novel 1-chloro-2-arylcyclohexenes employing the Suzuki cross coupling of 1-bromo-2-chlorocyclohexene with eleven different aryl boronic acids and Pd(dppfCl2·CH2Cl2 catalyst is reported.

  10. Structural confirmation of novel oligosaccharides isolated from sugar beet molasses.

    Science.gov (United States)

    Abe, Tatsuya; Kikuchi, Hiroto; Aritsuka, Tsutomu; Takata, Yusuke; Fukushi, Eri; Fukushi, Yukiharu; Kawabata, Jun; Ueno, Keiji; Onodera, Shuichi; Shiomi, Norio

    2016-07-01

    Eleven oligosaccharides were isolated from sugar beet molasses using carbon-Celite column chromatography and HPLC. The constituent sugars and linkage positions were determined using methylation analysis, MALDI-TOF-MS, and NMR measurements. The configurations of isolated oligosaccharides were confirmed based on detailed NMR analysis. Based on our results, three of the 11 oligosaccharides were novel. PMID:26920296

  11. Metabolism of oligosaccharides and starch in lactobacilli: a review

    Directory of Open Access Journals (Sweden)

    Michael eGänzle

    2012-09-01

    Full Text Available Oligosaccharides, compounds that are composed of 2 – 10 monosaccharide residues, are major carbohydrate sources in habitats populated by lactobacilli. Moreover, oligosaccharide metabolism is essential for ecological fitness of lactobacilli. Disaccharide metabolism by lactobacilli is well understood; however, few data on the metabolism of higher oligosaccharides are available. Research on the ecology of intestinal microbiota as well as the commercial application of prebiotics has shifted the interest from (digestible disaccharides to (indigestible higher oligosaccharides. This review provides an overview on oligosaccharide metabolism in lactobacilli. Emphasis is placed on maltodextrins, isomalto-oligosaccharides, fructo-oligosaccharides, galacto-oligosaccharides, and raffinose-family oligosaccharides. Starch is also considered. Metabolism is discussed on the basis of metabolic studies related to oligosaccharide metabolism, information on the cellular location and substrate specificity of carbohydrate transport systems, glycosyl hydrolases and phorphorylases, and the presence of metabolic genes in genomes of 28 strains of lactobacilli. Metabolic pathways for disaccharide metabolism often also enable the metabolism of tri- and tetrasaccharides. However, with the exception of amylase and levansucrase, metabolic enzymes for oligosaccharide conversion are intracellular and oligosaccharide metabolism is limited by transport. This general restriction to intracellular glycosyl hydrolases differentiates lactobacilli from other bacteria that adapted to intestinal habitats, particularly Bifidobacterium spp.

  12. Molybdatophosphoric acid as an efficient catalyst for the catalytic and chemoselective oxidation of sulfides to sulfoxides using urea hydrogen peroxide as a commercially available oxidant

    Directory of Open Access Journals (Sweden)

    ALIREZA HASANINEJAD

    2010-03-01

    Full Text Available An efficient procedure for the chemoselective oxidation of alkyl (aryl sulfides to the corresponding sulfoxides using urea hydrogen peroxide (UHP in the presence of a catalytic amount of molybdatophosphoric acid at room temperature is described. The advantages of described method are: generality, high yield and chemoselectivity, short reaction time, low cost and compliment with green chemistry protocols.

  13. Oligosaccharides of Cabernet Sauvignon, Syrah and Monastrell red wines.

    Science.gov (United States)

    Apolinar-Valiente, Rafael; Romero-Cascales, Inmaculada; Williams, Pascale; Gómez-Plaza, Encarna; López-Roca, José María; Ros-García, José María; Doco, Thierry

    2015-07-15

    Wine oligosaccharides were recently characterized and their concentrations, their composition and their roles on different wines remain to be determined. The concentration and composition of oligosaccharides in Cabernet Sauvignon, Syrah and Monastrell wines was studied. Oligosaccharide fractions were isolated by high resolution size-exclusion chromatography. The neutral and acidic sugar composition was determined by gas chromatography. The MS spectra of the oligosaccharides were performed on an AccuTOF mass spectrometer. Molar-mass distributions were determined by coupling size exclusion chromatography with a multi-angle light scattering device (MALLS) and a differential refractive index detector. Results showed significant differences in the oligosaccharidic fraction from Cabernet Sauvignon, Syrah and Monastrell wines. This study shows the influence that the grape variety seems have on the quantity, composition and structure of oligosaccharides in the finished wine. To our knowledge, this is the first report to research the oligosaccharides composition of Cabernet Sauvignon, Syrah and Monastrell wines.

  14. Anthrax carbohydrates, synthesis and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Russell W.; Boons, Geert-Jan; Quinn, Conrad; Vasan, Mahalakshmi; Wolfert, Margreet A.; Choudhury, Biswa; Kannenberg, Elmar; Leoff, Christine; Mehta, Alok; Saile, Elke; Rauvolfova, Jana; Wilkins, Patricia; Harvey, Alex J.

    2013-04-16

    The present invention presents the isolation, characterization and synthesis of oligosaccharides of Bacillus anthracis. Also presented are antibodies that bind to such saccharide moieties and various methods of use for such saccharide moieties and antibodies.

  15. Characterization of sugar beet pulp derived oligosaccharides

    NARCIS (Netherlands)

    Leijdekkers, M.

    2015-01-01

    Abstract This thesis aimed at characterizing complex mixtures of sugar beet pulp derived oligosaccharides, in order to be able to monitor and optimize the enzymatic saccharification of sugar beet pulp. Hydrophilic interaction chromatography with on-line evaporative light scattering

  16. Oligosaccharides isolated from Agave vera cruz

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Dorland, L.; Kamerling, J.P.; Satyanarayana, M.N.

    1977-01-01

    The structures of naturally occurring and enzymically synthesized oligosaccharides, consisting of fructose and glucose residues and having d.p. 3–8, in the stem of Agave vera cruz have been investigated by using methylation analysis, mass spectrometry, and p.m.r. spectroscopy. The naturally occurrin

  17. Aerobic dehydrogenation of cyclohexanone to cyclohexenone catalyzed by Pd(DMSO)2(TFA)2: evidence for ligand-controlled chemoselectivity.

    Science.gov (United States)

    Diao, Tianning; Pun, Doris; Stahl, Shannon S

    2013-06-01

    The dehydrogenation of cyclohexanones affords cyclohexenones or phenols via removal of 1 or 2 equiv of H2, respectively. We recently reported several Pd(II) catalyst systems that effect aerobic dehydrogenation of cyclohexanones with different product selectivities. Pd(DMSO)2(TFA)2 is unique in its high chemoselectivity for the conversion of cyclohexanones to cyclohexenones, without promoting subsequent dehydrogenation of cyclohexenones to phenols. Kinetic and mechanistic studies of these reactions reveal the key role of the dimethylsulfoxide (DMSO) ligand in controlling this chemoselectivity. DMSO has minimal kinetic influence on the rate of Pd(TFA)2-catalyzed dehydrogenation of cyclohexanone to cyclohexenone, while it strongly inhibits the second dehydrogenation step, conversion of cyclohexenone to phenol. These contrasting kinetic effects of DMSO provide the basis for chemoselective formation of cyclohexenones.

  18. Chemoselective and stereoselective lithium carbenoid mediated cyclopropanation of acyclic allylic alcohols.

    Science.gov (United States)

    Durán-Peña, M J; Flores-Giubi, M E; Botubol-Ares, J M; Harwood, L M; Collado, I G; Macías-Sánchez, A J; Hernández-Galán, R

    2016-03-01

    The reaction of geraniol with different lithium carbenoids generated from n-BuLi and the corresponding dihaloalkane has been evaluated. The reaction occurs in a chemo and stereoselective manner, which is consistent with a directing effect from the oxygen of the allylic moiety. Furthermore, a set of polyenes containing allylic hydroxyl or ether groups were chemoselectively and stereoselectively converted into the corresponding gem-dimethylcyclopropanes in one single step in moderate to good yields mediated by a lithium carbenoid generated in situ by the reaction of n-BuLi and 2,2-dibromopropane.

  19. Chemoselective Alternating Copolymerization of Limonene Dioxide and Carbon Dioxide: A New Highly Functional Aliphatic Epoxy Polycarbonate.

    Science.gov (United States)

    Li, Chunliang; Sablong, Rafaël J; Koning, Cor E

    2016-09-12

    The alternating copolymerization of biorenewable limonene dioxide with carbon dioxide (CO2 ) catalyzed by a zinc β-diiminate complex is reported. The chemoselective reaction results in linear amorphous polycarbonates that carry pendent methyloxiranes and exhibit glass transition temperatures (Tg ) up to 135 °C. These polycarbonates can be efficiently modified by thiols or carboxylic acids in combination with lithium hydroxide or tetrabutylphosphonium bromide as catalysts, respectively, without destruction of the main chain. Moreover, polycarbonates bearing pendent cyclic carbonates can be quantitatively prepared by CO2 insertion catalyzed by lithium bromide.

  20. Dearomatization Strategies in the Synthesis of Complex Natural Products

    OpenAIRE

    Roche, Stéphane P.; Porco, John A.

    2011-01-01

    Evolution in the field of the total synthesis of natural products has led to exciting developments over the last decade. Numerous chemo-selective and enantioselective methodologies have emerged from total syntheses, resulting in efficient access to many important natural product targets. This Review highlights recent developments concerning dearomatization, a powerful strategy for the total synthesis of architecturally complex natural products wherein planar, aromatic scaffolds are converted ...

  1. Oligosaccharide formation during commercial pear juice processing.

    Science.gov (United States)

    Willems, Jamie L; Low, Nicholas H

    2016-08-01

    The effect of enzyme treatment and processing on the oligosaccharide profile of commercial pear juice samples was examined by high performance anion exchange chromatography with pulsed amperometric detection and capillary gas chromatography with flame ionization detection. Industrial samples representing the major stages of processing produced with various commercial enzyme preparations were studied. Through the use of commercially available standards and laboratory scale enzymatic hydrolysis of pectin, starch and xyloglucan; galacturonic acid oligomers, glucose oligomers (e.g., maltose and cellotriose) and isoprimeverose were identified as being formed during pear juice production. It was found that the majority of polysaccharide hydrolysis and oligosaccharide formation occurred during enzymatic treatment at the pear mashing stage and that the remaining processing steps had minimal impact on the carbohydrate-based chromatographic profile of pear juice. Also, all commercial enzyme preparations and conditions (time and temperature) studied produced similar carbohydrate-based chromatographic profiles. PMID:26988479

  2. Total synthesis of atropurpuran.

    Science.gov (United States)

    Gong, Jing; Chen, Huan; Liu, Xiao-Yu; Wang, Zhi-Xiu; Nie, Wei; Qin, Yong

    2016-01-01

    Due to their architectural intricacy and biological significance, the synthesis of polycyclic diterpenes and their biogenetically related alkaloids have been the subject of considerable interest over the last few decades, with progress including the impressive synthesis of several elusive targets. Despite tremendous efforts, conquering the unique structural types of this large natural product family remains a long-term challenge. The arcutane diterpenes and related alkaloids, bearing a congested tetracyclo[5.3.3.0(4,9).0(4,12)]tridecane unit, are included in these unsolved enigmas. Here we report a concise approach to the construction of the core structure of these molecules and the first total synthesis of (±)-atropurpuran. Pivotal features of the synthesis include an oxidative dearomatization/intramolecular Diels-Alder cycloaddition cascade, sequential aldol and ketyl-olefin cyclizations to assemble the highly caged framework, and a chemoselective and stereoselective reduction to install the requisite allylic hydroxyl group in the target molecule. PMID:27387707

  3. Distribution of Heparan Sulfate Oligosaccharides in Murine Mucopolysaccharidosis Type IIIA

    OpenAIRE

    Kerryn Mason; Peter Meikle; John Hopwood; Maria Fuller

    2014-01-01

    Heparan sulfate (HS) catabolism begins with endo-degradation of the polysaccharide to smaller HS oligosaccharides, followed by the sequential action of exo-enzymes to reduce these oligosaccharides to monosaccharides and inorganic sulfate. In mucopolysaccharidosis type IIIA (MPS IIIA) the exo-enzyme, N-sulfoglucosamine sulfohydrolase, is deficient resulting in an inability to hydrolyze non-reducing end glucosamine N-sulfate esters. Consequently, partially degraded HS oligosaccharides with non-...

  4. Structural confirmation of oligosaccharides newly isolated from sugar beet molasses

    OpenAIRE

    Abe Tatsuya; Horiuchi Kenichi; Kikuchi Hiroto; Aritsuka Tsutomu; Takata Yusuke; Fukushi Eri; Fukushi Yukiharu; Kawabata Jun; Ueno Keiji; Onodera Shuichi; Shiomi Norio

    2012-01-01

    Abstract Background Sugar beet molasses is a viscous by-product of the processing of sugar beets into sugar. The molasses is known to contain sucrose and raffinose, a typical trisaccharide, with a well-established structure. Although sugar beet molasses contains various other oligosaccharides as well, the structures of those oligosaccharides have not been examined in detail. The purpose of this study was isolation and structural confirmation of these other oligosaccharides found in sugar beet...

  5. In Vitro Fermentation of Porcine Milk Oligosaccharides and Galacto-oligosaccharides Using Piglet Fecal Inoculum.

    Science.gov (United States)

    Difilippo, Elisabetta; Pan, Feipeng; Logtenberg, Madelon; Willems, Rianne H A M; Braber, Saskia; Fink-Gremmels, Johanna; Schols, Henk A; Gruppen, Harry

    2016-03-16

    In this study, the in vitro fermentation by piglet fecal inoculum of galacto-oligosaccharides (GOS) and porcine milk oligosaccharides (PMOs) was investigated to identify possible preferences for individual oligosaccharide structures by piglet microbiota. First, acidic PMOs and GOS with degrees of polymerization 4-7 were depleted within 12 h of fermentation, whereas fucosylated and phosphorylated PMOs were partially resistant to fermentation. GOS structures containing β1-3 and β1-2 linkages were preferably fermented over GOS containing β1-4 and β1-6 linkages. Upon in vitro fermentation, acetate and butyrate were produced as the main organic acids. GOS fermentation by piglet inoculum showed a unique fermentation pattern with respect to preference of GOS size and organic acids production.

  6. Effect of fructo-oligosaccharide and isomalto-oligosaccharide addition on baking quality of frozen dough.

    Science.gov (United States)

    Park, Eun Young; Jang, Sung-Bum; Lim, Seung-Taik

    2016-12-15

    The baking quality of frozen doughs containing different levels of fructo-oligosaccharides (FO) or isomalto-oligosaccharides (IMO) (3-9%, w/w flour), and stored for 0-8weeks at -18°C, was examined. The addition of FO or IMO increased the proof volume of the dough and the loaf volume of bread prepared from frozen dough. A 6% addition of FO or IMO was optimum, giving the highest proof volume and bread loaf volume, but a higher concentration than 6% induced low baking quality including lower proof volume and bread loaf volume. The bread crumb was moister and softer after the addition of FO or IMO before, and even after, frozen storage. Darker crumb colour was observed in the bread after the addition of FO or IMO. The oligosaccharides added to the frozen dough were effective in improving the quality of bread made from frozen dough, except for resulting in a darker bread crumb. PMID:27451167

  7. Oligosaccharides of milk and colostrum in non-human mammals.

    Science.gov (United States)

    Urashima, T; Saito, T; Nakamura, T; Messer, M

    2001-05-01

    Mammalian milk or colostrum usually contains, in addition to lactose, a variety of neutral and acidic oligosaccharides. Although the oligosaccharides of human milk have been reviewed in several recent publications, those of non-human mammals have received much less attention. This paper reviews the chemical structures and the variety of milk oligosaccharides in species other than humans, including placental mammals (e.g. primates, domestic herbivores, bears and other carnivores, the rat and the elephant) as well as monotremes (platypus and echidna) and marsupials (e.g. wallaby). The gastrointestinal digestion and absorption and the possible biological functions of these oligosaccharides are also discussed. PMID:11925504

  8. A protecting group-free synthesis of the Colorado potato beetle pheromone

    NARCIS (Netherlands)

    Wu, Zhongtao; Buter, Jeffrey; Minnaard, Adriaan J.; Jäger, Manuel; Dickschat, J.S.

    2013-01-01

    A novel synthesis of the aggregation pheromone of the Colorado potato beetle, Leptinotarsa decemlineata, has been developed based on a Sharpless asymmetric epoxidation in combination with a chemoselective alcohol oxidation using catalytic [(neocuproine)PdOAc](2)OTf2. Employing this approach, the phe

  9. Solid-phase synthesis of new saphenamycin analogues with antimicrobial activity

    DEFF Research Database (Denmark)

    Laursen, Jane B.; de Visser, P.C.; Nielsen, H.K.;

    2002-01-01

    An array of 12 new saphenamycin analogues modified at the benzoate moiety was synthesized on solid support. Synthesis commenced with a chemoselective anchoring of saphenic acid through the carboxyl group to a 2-chlorotrityl functionalized polystyrene resin. The secondary alcohol was acylated...

  10. Seaweed Polysaccharides and Derived Oligosaccharides Stimulate Defense Responses and Protection Against Pathogens in Plants

    Directory of Open Access Journals (Sweden)

    Alejandra Moenne

    2011-11-01

    Full Text Available Plants interact with the environment by sensing “non-self” molecules called elicitors derived from pathogens or other sources. These molecules bind to specific receptors located in the plasma membrane and trigger defense responses leading to protection against pathogens. In particular, it has been shown that cell wall and storage polysaccharides from green, brown and red seaweeds (marine macroalgae corresponding to ulvans, alginates, fucans, laminarin and carrageenans can trigger defense responses in plants enhancing protection against pathogens. In addition, oligosaccharides obtained by depolymerization of seaweed polysaccharides also induce protection against viral, fungal and bacterial infections in plants. In particular, most seaweed polysaccharides and derived oligosaccharides trigger an initial oxidative burst at local level and the activation of salicylic (SA, jasmonic acid (JA and/or ethylene signaling pathways at systemic level. The activation of these signaling pathways leads to an increased expression of genes encoding: (i Pathogenesis-Related (PR proteins with antifungal and antibacterial activities; (ii defense enzymes such as pheylalanine ammonia lyase (PAL and lipoxygenase (LOX which determine accumulation of phenylpropanoid compounds (PPCs and oxylipins with antiviral, antifugal and antibacterial activities and iii enzymes involved in synthesis of terpenes, terpenoids and/or alkaloids having antimicrobial activities. Thus, seaweed polysaccharides and their derived oligosaccharides induced the accumulation of proteins and compounds with antimicrobial activities that determine, at least in part, the enhanced protection against pathogens in plants.

  11. Synthesis of Tigogenyl 2-Deoxy-2-phthalimido-D-glucopyranoside Derivatives and Study of their 1H-NMR Spectrum

    Institute of Scientific and Technical Information of China (English)

    Shu Jie HOU; Chuan Chun ZOU; Ping Sheng LEI; De Quan YU

    2004-01-01

    Two protected tigogenyl glycosides were synthesized via parallel synthesis of oligosaccharide. Using chemical synthesis and conformational analysis the reason of the proton signal of 2" acetyl group shifted up field in 1H-NMR was discussed.

  12. Engineering the glucansucrase GTFR enzyme reaction and glycosidic bond specificity: Toward tailor-made polymer and oligosaccharide products

    OpenAIRE

    Hellmuth, Hendrik; Wittrock, Sabine; Kralj, Slavko; Dijkhuizen, Lubbert; Hofer, Bernd; Seibel, Juergen; Seibel, Jürgen

    2008-01-01

    Two long-standing questions about glucansucrases (EC 2.4.1.5) are how they control oligosaccharide versus polysaccharide synthesis and how they direct their glycosidic linkage specificity. This information is required for the production of tailor-made saccharides. Mutagenesis promises to be an effective tool for enzyme engineering approaches for altering the regioselectivity and acceptor substrate specificity. Therefore, we chose the most conserved motif around the transition state stabilizer...

  13. Preparation of mesoporous SiO2@azobenzene-COOH chemoselective nanoprobes for comprehensive mapping of amino metabolites in human serum.

    Science.gov (United States)

    Li, Hua; Qin, Qian; Qiao, Lizhen; Shi, Xianzhe; Xu, Guowang

    2015-06-30

    A novel type of mesoporous SiO2@H4/D4 tagged azobenzene-COOH chemoselective nanoprobe was developed for comprehensive mapping of amino metabolites in complex biological samples with high specificity and sensitivity.

  14. Physiological effects of consumption of fructo-oligosaccharides and transgalacto-oligosaccharides.

    NARCIS (Netherlands)

    Alles, M.S.

    1998-01-01

    Oligosaccharides naturally occur in many raw materials that are used for the manufacture of human foods. Plant oligosacccharides are often not digestible in the upper part of the gastrointestinal tract, but may be fermented in the colon by the intestinal microflora. These non-digestible oligosacchar

  15. Surface-Bound Ligands Modulate Chemoselectivity and Activity of a Bimetallic Nanoparticle Catalyst

    KAUST Repository

    Vu, Khanh B.

    2015-04-03

    "Naked" metal nanoparticles (NPs) are thermodynamically and kinetically unstable in solution. Ligands, surfactants, or polymers, which adsorb at a particle\\'s surface, can be used to stabilize NPs; however, such a mode of stabilization is undesirable for catalytic applications because the adsorbates block the surface active sites. The catalytic activity and the stability of NPs are usually inversely correlated. Here, we describe an example of a bimetallic (PtFe) NP catalyst stabilized by carboxylate surface ligands that bind preferentially to one of the metals (Fe). NPs stabilized by fluorous ligands were found to be remarkably competent in catalyzing the hydrogenation of cinnamaldehyde; NPs stabilized by hydrocarbon ligands were significantly less active. The chain length of the fluorous ligands played a key role in determining the chemoselectivity of the FePt NP catalysts. (Chemical Presented). © 2015 American Chemical Society.

  16. Engineering the glucansucrase GTFR enzyme reaction and glycosidic bond specificity: toward tailor-made polymer and oligosaccharide products.

    Science.gov (United States)

    Hellmuth, Hendrik; Wittrock, Sabine; Kralj, Slavko; Dijkhuizen, Lubbert; Hofer, Bernd; Seibel, Jürgen

    2008-06-24

    Two long-standing questions about glucansucrases (EC 2.4.1.5) are how they control oligosaccharide versus polysaccharide synthesis and how they direct their glycosidic linkage specificity. This information is required for the production of tailor-made saccharides. Mutagenesis promises to be an effective tool for enzyme engineering approaches for altering the regioselectivity and acceptor substrate specificity. Therefore, we chose the most conserved motif around the transition state stabilizer in glucansucrases for a random mutagenesis of the glucansucrase GTFR of Streptococcus oralis, yielding different variants with altered reaction specificity. Modifications at position S628 achieved by saturation mutagenesis guided the reaction toward the synthesis of short chain oligosaccharides with a drastically increased yield of isomaltose (47%) or leucrose (64%). Alternatively, GTFR variant R624G/V630I/D717A exhibited a drastic switch in regioselectivity from a dextran type with mainly alpha-1,6-glucosidic linkages to a mutan type polymer with predominantly alpha-1,3-glucosidic linkages. Targeted modifications demonstrated that both mutations near the transition state stabilizer, R624G and V630I, are contributing to this alteration. It is thus shown that mutagenesis can guide the transglycosylation reaction of glucansucrase enzymes toward the synthesis of (a) various short chain oligosaccharides or (b) novel polymers with completely altered linkages, without compromising their high transglycosylation activity and efficiency. PMID:18512955

  17. Entamoeba histolytica-Secreted Products Degrade Colonic Mucin Oligosaccharides

    OpenAIRE

    Moncada, Darcy; Keller, Kathy; Chadee, Kris

    2005-01-01

    Degradation of the mucus layer by Entamoeba histolytica is a prerequisite for invasion of the colonic mucosa. In this study, we demonstrate that amoeba-secreted products degrade 3H-labeled and native colonic mucin oligosaccharides independently of proteolytic activity. We conclude that E. histolytica degrades mucin oligosaccharides, which may facilitate parasite invasion of the colon.

  18. Oligosaccharides in goat milk: structure, health effects and isolation

    NARCIS (Netherlands)

    Kiskini, A.; Difilippo, E.

    2013-01-01

    Oligosaccharides have been widely recognized for their prebiotic and anti-infective properties. Among the different types of mammalian milk, the one of humans is the richest source of naturally derived oligosaccharides. However, their use as a basis for functional foods is hampered, due to their str

  19. Chromatographic Separations of Enantiomers and Underivatized Oligosaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ying [Iowa State Univ., Ames, IA (United States)

    2004-01-01

    My graduate research has focused on separation science and bioanalytical analysis, which emphasized in method development. It includes three major areas: enantiomeric separations using high performance liquid chromatography (HPLC), Super/subcritical fluid chromatography (SFC), and capillary electrophoresis (CE); drug-protein binding behavior studies using CE; and carbohydrate analysis using liquid chromatograph-electrospray ionization mass spectrometry (LC-ESI-MS). Enantiomeric separations continue to be extremely important in the pharmaceutical industry. An in-depth evaluation of the enantiomeric separation capabilities of macrocyclic glycopeptides CSPs with SFC mobile phases was investigated using a set of over 100 chiral compounds. It was found that the macrocyclic based CSPs were able to separate enantiomers of various compounds with different polarities and functionalities. Seventy percent of all separations were achieved in less than 4 min due to the high flow rate (4.0 ml/min) that can be used in SFC. Drug-protein binding is an important process in determining the activity and fate of a drug once it enters the body. Two drug/protein systems have been studied using frontal analysis CE method. More sensitive fluorescence detection was introduced in this assay, which overcame the problem of low sensitivity that is common when using UV detection for drug-protein studies. In addition, the first usage of an argon ion laser with 257 nm beam coupled with CCD camera as a frontal analysis detection method enabled the simultaneous observation of drug fluorescence as well as the protein fluorescence. LC-ESI-MS was used for the separation and characterization of underivatized oligosaccharide mixtures. With the limits of detection as low as 50 picograms, all individual components of oligosaccharide mixtures (up to 11 glucose-units long) were baseline resolved on a Cyclobond I 2000 column and detected using ESI-MS. This system is characterized by high chromatographic

  20. Chromatographic Separations of Enantiomers and Underivatized Oligosaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Ying Liu

    2004-12-19

    My graduate research has focused on separation science and bioanalytical analysis, which emphasized in method development. It includes three major areas: enantiomeric separations using high performance liquid chromatography (HPLC), Super/subcritical fluid chromatography (SFC), and capillary electrophoresis (CE); drug-protein binding behavior studies using CE; and carbohydrate analysis using liquid chromatograph-electrospray ionization mass spectrometry (LC-ESI-MS). Enantiomeric separations continue to be extremely important in the pharmaceutical industry. An in-depth evaluation of the enantiomeric separation capabilities of macrocyclic glycopeptides CSPs with SFC mobile phases was investigated using a set of over 100 chiral compounds. It was found that the macrocyclic based CSPs were able to separate enantiomers of various compounds with different polarities and functionalities. Seventy percent of all separations were achieved in less than 4 min due to the high flow rate (4.0 ml/min) that can be used in SFC. Drug-protein binding is an important process in determining the activity and fate of a drug once it enters the body. Two drug/protein systems have been studied using frontal analysis CE method. More sensitive fluorescence detection was introduced in this assay, which overcame the problem of low sensitivity that is common when using UV detection for drug-protein studies. In addition, the first usage of an argon ion laser with 257 nm beam coupled with CCD camera as a frontal analysis detection method enabled the simultaneous observation of drug fluorescence as well as the protein fluorescence. LC-ESI-MS was used for the separation and characterization of underivatized oligosaccharide mixtures. With the limits of detection as low as 50 picograms, all individual components of oligosaccharide mixtures (up to 11 glucose-units long) were baseline resolved on a Cyclobond I 2000 column and detected using ESI-MS. This system is characterized by high chromatographic

  1. Chromatographic Separations of Enantiomers and Underivatized Oligosaccharides

    International Nuclear Information System (INIS)

    My graduate research has focused on separation science and bioanalytical analysis, which emphasized in method development. It includes three major areas: enantiomeric separations using high performance liquid chromatography (HPLC), Super/subcritical fluid chromatography (SFC), and capillary electrophoresis (CE); drug-protein binding behavior studies using CE; and carbohydrate analysis using liquid chromatograph-electrospray ionization mass spectrometry (LC-ESI-MS). Enantiomeric separations continue to be extremely important in the pharmaceutical industry. An in-depth evaluation of the enantiomeric separation capabilities of macrocyclic glycopeptides CSPs with SFC mobile phases was investigated using a set of over 100 chiral compounds. It was found that the macrocyclic based CSPs were able to separate enantiomers of various compounds with different polarities and functionalities. Seventy percent of all separations were achieved in less than 4 min due to the high flow rate (4.0 ml/min) that can be used in SFC. Drug-protein binding is an important process in determining the activity and fate of a drug once it enters the body. Two drug/protein systems have been studied using frontal analysis CE method. More sensitive fluorescence detection was introduced in this assay, which overcame the problem of low sensitivity that is common when using UV detection for drug-protein studies. In addition, the first usage of an argon ion laser with 257 nm beam coupled with CCD camera as a frontal analysis detection method enabled the simultaneous observation of drug fluorescence as well as the protein fluorescence. LC-ESI-MS was used for the separation and characterization of underivatized oligosaccharide mixtures. With the limits of detection as low as 50 picograms, all individual components of oligosaccharide mixtures (up to 11 glucose-units long) were baseline resolved on a Cyclobond I 2000 column and detected using ESI-MS. This system is characterized by high chromatographic

  2. A hybrid strategy for the preparation of 13C-labeled high-mannose-type oligosaccharides with terminal glucosylation for NMR study

    International Nuclear Information System (INIS)

    Stable isotopic labeling dramatically facilitates NMR studies of oligosaccharides. We previously established a method for overexpressing homogeneous high-mannose-type oligosaccharides with metabolic 13C labeling using genetically engineered yeast cells. To extend the applicability of this methodology, we combined it with chemoenzymatic synthesis using a specific glucosyl transferase. Our hybrid approach has enabled the production of a uniformly and selectively 13C-labeled dodecasaccharide with terminal glucosylation, a signal recognized by molecular chaperones, providing useful NMR tools for detailed conformational analyses. (author)

  3. Multifunctional fructans and raffinose family oligosaccharides

    Directory of Open Access Journals (Sweden)

    Wim eVan den Ende

    2013-07-01

    Full Text Available Fructans and Raffinose Family Oligosaccharides (RFOs are the two most important classes of water soluble carbohydrates in plants. Recent progress is summarized on their metabolism (and regulation and on their functions in plants and in food (prebiotics, antioxidants. Interest has shifted from the classic inulin-type fructans to more complex fructans. Similarly, alternative RFOs were discovered next to the classic RFOs. Considerable progress has been made in the understanding of structure-function relationships among different kinds of plant fructan metabolizing enzymes. This helps to understand their evolution from (invertase ancestors, and the evolution and role of so-called defective invertases. Both fructans and RFOs can act as reserve carbohydrates, membrane stabilizers and stress tolerance mediators. Fructan metabolism can also play a role in osmoregulation (e.g. flower opening and source-sink relationships. Here, two novel emerging roles are highlighted. First, fructans and RFOs may contribute to overall cellular ROS homeostasis by specific ROS scavenging processes in the vicinity of organellar membranes (e.g. vacuole, chloroplasts. Second, it is hypothesized that small fructans and RFOs act as phloem-mobile signaling compounds under stress. It is speculated that such underlying antioxidant and oligosaccharide signaling mechanisms contribute to disease prevention in plants as well as in animals and in humans.

  4. Aerobic Dehydrogenation of Cyclohexanone to Cyclohexenone Catalyzed by Pd(DMSO)2(TFA)2: Evidence for Ligand-Controlled Chemoselectivity

    OpenAIRE

    Diao, Tianning; Pun, Doris; Stahl, Shannon S.

    2013-01-01

    The dehydrogenation of cyclohexanones affords cyclohexenones or phenols via removal of one or two equivalents of H2, respectively. We recently reported several PdII catalyst systems that effect aerobic dehydrogenation of cyclohexanones with different product selectivities. Pd(DMSO)2(TFA)2 is unique in its high chemoselectivity for the conversion of cyclohexanones to cyclohexenones, without promoting subsequent dehydrogenation of cyclohexenones to phenols. Kinetic and mechanistic studies of th...

  5. Chemoselective N-nitrosation of secondary amines under heterogeneous and mild conditions via in situ generation of HNO2

    Institute of Scientific and Technical Information of China (English)

    Arash Ghorbani-Choghamarani; Hamid Goudarziafshar; Somaieh Rezaee; Saiedeh Shima Mortazavi

    2009-01-01

    A wide variety of secondary amines are chemoselectively subjected to N-nitrosation reaction with treatment of citric acid and NaNO2 in the presence of wet SiO2(50%,w/w)in dichloromethane at room temperatture under heterogeneous conditions.The N-nitrosation method is very simle and products can be easily isolated with good to high yields.

  6. Novel α-L-Fucosidases from a Soil Metagenome for Production of Fucosylated Human Milk Oligosaccharides.

    Directory of Open Access Journals (Sweden)

    Mateusz Lezyk

    Full Text Available This paper describes the discovery of novel α-L-fucosidases and evaluation of their potential to catalyse the transglycosylation reaction leading to production of fucosylated human milk oligosaccharides. Seven novel α-L-fucosidase-encoding genes were identified by functional screening of a soil-derived metagenome library and expressed in E. coli as recombinant 6xHis-tagged proteins. All seven fucosidases belong to glycosyl hydrolase family 29 (GH 29. Six of the seven α-L-fucosidases were substrate-inhibited, moderately thermostable and most hydrolytically active in the pH range 6-7, when tested with para-nitrophenyl-α-L-fucopyranoside (pNP-Fuc as the substrate. In contrast, one fucosidase (Mfuc6 exhibited a high pH optimum and an unusual sigmoidal kinetics towards pNP-Fuc substrate. When tested for trans-fucosylation activity using pNP-Fuc as donor, most of the enzymes were able to transfer fucose to pNP-Fuc (self-condensation or to lactose. With the α-L-fucosidase from Thermotoga maritima and the metagenome-derived Mfuc5, different fucosyllactose variants including the principal fucosylated HMO 2'-fucosyllactose were synthesised in yields of up to ~6.4%. Mfuc5 was able to release fucose from xyloglucan and could also use it as a fucosyl-donor for synthesis of fucosyllactose. This is the first study describing the use of glycosyl hydrolases for the synthesis of genuine fucosylated human milk oligosaccharides.

  7. Design, modeling, expression, and chemoselective PEGylation of a new nanosize cysteine analog of erythropoietin

    Directory of Open Access Journals (Sweden)

    Ahangari Cohan R

    2011-06-01

    Full Text Available Reza Ahangari Cohan1, Armin Madadkar-Sobhani2,3, Hossein Khanahmad1, Farzin Roohvand4, Mohammad Reza Aghasadeghi4, Mohammad Hossein Hedayati5, Zahra Barghi5, Mehdi Shafiee Ardestani4, Davoud Nouri Inanlou1, Dariush Norouzian11Research and Development Department, Production and Research Complex, Pasteur Institute of Iran, Tehran, Iran; 2Department of Bioinformatics, Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran; 3Department of Life Sciences, Barcelona Supercomputing Center, Barcelona, Spain; 4Hepatitis and AIDS Department, Pasteur Institute of Iran, Tehran, Iran; 5Quality Control Department, Production and Research Complex, Pasteur Institute of Iran, Tehran, IranBackground: Recombinant human erythropoietin (rhEPO is considered to be one of the most pivotal pharmaceutical drugs in the market because of its clinical application in the treatment of anemia-associated disorders worldwide. However, like other therapeutic proteins, it does not have suitable pharmacokinetic properties for it to be administrated at least two to three times per week. Chemoselective cysteine PEGylation, employing molecular dynamics and graphics in in silico studies, can be considered to overcome such a problem.Methods: A special kind of EPO analog was elicited based on a literature review, homology modeling, molecular dynamic simulation, and factors affecting the PEGylation reaction. Then, cDNA of the selected analog was generated by site-directed mutagenesis and subsequently cloned into the expression vector. The construct was transfected to Chinese hamster ovary/dhfr- cells, and highly expressed clones were selected via methotrexate amplification. Ion-immobilized affinity and size exclusion (SE chromatography techniques were used to purify the expressed analog. Thereafter, chemoselective PEGylation was performed and a nanosize PEGylated EPO was obtained through dialysis. The in vitro biologic assay and in vivo pharmacokinetic parameters were

  8. The total synthesis of (-)-nitidasin.

    Science.gov (United States)

    Hog, Daniel T; Huber, Florian M E; Mayer, Peter; Trauner, Dirk

    2014-08-01

    Nitidasin is a pentacyclic sesterterpenoid with a rare 5-8-6-5 carbon skeleton that was isolated from the Peruvian folk medicine "Hercampuri". It belongs to a small class of sesterterpenoids that feature an isopropyl trans-hydrindane moiety fused to a variety of other ring systems. As a first installment of our general approach toward these natural products, we report the total synthesis of the title compound. Our stereoselective, convergent route involves the addition of a complex alkenyl lithium compound to a trans-hydrindanone, followed by chemoselective epoxidation, ring-closing olefin metathesis, and redox adjustment.

  9. Synbiotic matrices derived from plant oligosaccharides and polysaccharides

    Science.gov (United States)

    A porous synbiotic matrix was prepared by lyophilization of alginate and pectin or fructan oligosaccharides and polysaccharides cross-linked with calcium. These synbiotic matrices were excellent physical structures to support the growth of Lactobacillus acidophilus (1426) and Lactobacillus reuteri (...

  10. Applications of Mass Spectrometry to Structural Analysis of Marine Oligosaccharides

    Directory of Open Access Journals (Sweden)

    Yinzhi Lang

    2014-06-01

    Full Text Available Marine oligosaccharides have attracted increasing attention recently in developing potential drugs and biomaterials for their particular physical and chemical properties. However, the composition and sequence analysis of marine oligosaccharides are very challenging for their structural complexity and heterogeneity. Mass spectrometry (MS has become an important technique for carbohydrate analysis by providing more detailed structural information, including molecular mass, sugar constituent, sequence, inter-residue linkage position and substitution pattern. This paper provides an overview of the structural analysis based on MS approaches in marine oligosaccharides, which are derived from some biologically important marine polysaccharides, including agaran, carrageenan, alginate, sulfated fucan, chitosan, glycosaminoglycan (GAG and GAG-like polysaccharides. Applications of electrospray ionization mass spectrometry (ESI-MS are mainly presented and the general applications of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS are also outlined. Some technical challenges in the structural analysis of marine oligosaccharides by MS have also been pointed out.

  11. Deproteinated palm kernel cake-derived oligosaccharides: A preliminary study

    Science.gov (United States)

    Fan, Suet Pin; Chia, Chin Hua; Fang, Zhen; Zakaria, Sarani; Chee, Kah Leong

    2014-09-01

    Preliminary study on microwave-assisted hydrolysis of deproteinated palm kernel cake (DPKC) to produce oligosaccharides using succinic acid was performed. Three important factors, i.e., temperature, acid concentration and reaction time, were selected to carry out the hydrolysis processes. Results showed that the highest yield of DPKC-derived oligosaccharides can be obtained at a parameter 170 °C, 0.2 N SA and 20 min of reaction time.

  12. A Novel Oligosaccharide from the Mucus of the Loach

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A novel oligosaccharide was isolated and purified from the mucus of the loach,Misgurnus anguillicaudatus.It was identified by several qualitative tests and characterized by elementary analysis,UV and IR spectrum.Its average molecular weight (Mw=1539.4) was determined by gel permeation chromatography.The major structural monomers of Misgurnus anguillicaudatus oligosaccharide were identified to be D-galactose and L-fucose by paper chromatography and gas chromatography.

  13. Distribution of Heparan Sulfate Oligosaccharides in Murine Mucopolysaccharidosis Type IIIA

    Science.gov (United States)

    Mason, Kerryn; Meikle, Peter; Hopwood, John; Fuller, Maria

    2014-01-01

    Heparan sulfate (HS) catabolism begins with endo-degradation of the polysaccharide to smaller HS oligosaccharides, followed by the sequential action of exo-enzymes to reduce these oligosaccharides to monosaccharides and inorganic sulfate. In mucopolysaccharidosis type IIIA (MPS IIIA) the exo-enzyme, N-sulfoglucosamine sulfohydrolase, is deficient resulting in an inability to hydrolyze non-reducing end glucosamine N-sulfate esters. Consequently, partially degraded HS oligosaccharides with non-reducing end glucosamine sulfate esters accumulate. We investigated the distribution of these HS oligosaccharides in tissues of a mouse model of MPS IIIA using high performance liquid chromatography electrospray ionization-tandem mass spectrometry. Oligosaccharide levels were compared to total uronic acid (UA), which was used as a measure of total glycosaminoglycan. Ten oligosaccharides, ranging in size from di- to hexasaccharides, were present in all the tissues examined including brain, spleen, lung, heart, liver, kidney and urine. However, the relative levels varied up to 10-fold, suggesting different levels of HS turnover and storage. The relationship between the di- and tetrasaccharides and total UA was tissue specific with spleen and kidney showing a different disaccharide:total UA ratio than the other tissues. The hexasaccharides showed a stronger correlation with total UA in all tissue types suggesting that hexasaccharides may more accurately reflect the storage burden in these tissues. PMID:25513953

  14. Distribution of Heparan Sulfate Oligosaccharides in Murine Mucopolysaccharidosis Type IIIA

    Directory of Open Access Journals (Sweden)

    Kerryn Mason

    2014-12-01

    Full Text Available Heparan sulfate (HS catabolism begins with endo-degradation of the polysaccharide to smaller HS oligosaccharides, followed by the sequential action of exo-enzymes to reduce these oligosaccharides to monosaccharides and inorganic sulfate. In mucopolysaccharidosis type IIIA (MPS IIIA the exo-enzyme, N-sulfoglucosamine sulfohydrolase, is deficient resulting in an inability to hydrolyze non-reducing end glucosamine N-sulfate esters. Consequently, partially degraded HS oligosaccharides with non-reducing end glucosamine sulfate esters accumulate. We investigated the distribution of these HS oligosaccharides in tissues of a mouse model of MPS IIIA using high performance liquid chromatography electrospray ionization-tandem mass spectrometry. Oligosaccharide levels were compared to total uronic acid (UA, which was used as a measure of total glycosaminoglycan. Ten oligosaccharides, ranging in size from di- to hexasaccharides, were present in all the tissues examined including brain, spleen, lung, heart, liver, kidney and urine. However, the relative levels varied up to 10-fold, suggesting different levels of HS turnover and storage. The relationship between the di- and tetrasaccharides and total UA was tissue specific with spleen and kidney showing a different disaccharide:total UA ratio than the other tissues. The hexasaccharides showed a stronger correlation with total UA in all tissue types suggesting that hexasaccharides may more accurately reflect the storage burden in these tissues.

  15. Designing a binding interface for control of cancer cell adhesion via 3D topography and metabolic oligosaccharide engineering.

    Science.gov (United States)

    Du, Jian; Che, Pao-Lin; Wang, Zhi-Yun; Aich, Udayanath; Yarema, Kevin J

    2011-08-01

    This study combines metabolic oligosaccharide engineering (MOE), a technology where the glycocalyx of living cells is endowed with chemical features not normally found in sugars, with custom-designed three-dimensional biomaterial substrates to enhance the adhesion of cancer cells and control their morphology and gene expression. Specifically, Ac(5)ManNTGc, a thiol-bearing analog of N-acetyl-d-mannosamine (ManNAc) was used to introduce thiolated sialic acids into the glycocalyx of human Jurkat T-lymphoma derived cells. In parallel 2D films and 3D electrospun nanofibrous scaffolds were prepared from polyethersulfone (PES) and (as controls) left unmodified or aminated. Alternately, the materials were malemided or gold-coated to provide bio-orthogonal binding partners for the thiol groups newly expressed on the cell surface. Cell attachment was modulated by both the topography of the substrate surface and by the chemical compatibility of the binding interface between the cell and the substrate; a substantial increase in binding for normally non-adhesive Jurkat line for 3D scaffold compared to 2D surfaces with an added degree of adhesion resulting from chemoselective binding to malemidede-derivatived or gold-coated surfaces. In addition, the morphology of the cells attached to the 3D scaffolds via MOE-mediated adhesion was dramatically altered and the expression of genes involved in cell adhesion changed in a time-dependent manner. This study showed that cell adhesion could be enhanced, gene expression modulated, and cell fate controlled by introducing the 3D topograhical cues into the growth substrate and by creating a glycoengineered binding interface where the chemistry of both the cell surface and biomaterials scaffold was controlled to facilitate a new mode of carbohydrate-mediated adhesion. PMID:21549424

  16. Synthesis and characterization of new oligosaccharides with prebiotic activity

    OpenAIRE

    Montenegro, Maria Inês Pereira

    2014-01-01

    A relevância da microbiota intestinal na manutenção da saúde do hospedeiro é bem conhecida e, nas últimas décadas, a consciencialização dos consumidores para a escolha de alimentos saudáveis tem vindo a aumentar. Existem diversas estratégias para estimular a proliferação de bactérias intestinais benéficas, incluindo o consumo de prebióticos. Atualmente, existe uma vasta gama de hidratos de carbono prebióticos no mercado, a maior parte isolados de polissacarídeos de plantas, de que são exemplo...

  17. Enzymatic Synthesis and Anti-Allergic Activities of Curcumin Oligosaccharides

    OpenAIRE

    Hiroki Hamada; Kei Shimoda

    2010-01-01

    Curcumin 4'-O-glucooligosaccharides were synthesized by a two step-enzymatic method using almond β-glucosidase and cyclodextrin glucanotransferase (CGTase). Curcumin was glucosylated to curcumin 4'-O-β-D-glucopyranoside by almond β-glucosidase in 19% yield. Curcumin 4'-O-β-D-glucopyranoside was converted into curcumin 4'-O-β-glucooligosaccharides, i.e. 4'-O-β-maltoside (51%) and 4'-O-β-maltotrioside (25%), by further CGTase-catalyzed glycosylation. Curcumin 4'-O-β-glycosides showed suppressiv...

  18. Recent development of phosphorylases possessing large potential for oligosaccharide synthesis

    DEFF Research Database (Denmark)

    Nakai, Hiroyuki; Kitaoka, Motomitsu; Svensson, Birte;

    2013-01-01

    Phosphorylases are one group of carbohydrate active enzymes involved in the cleavage and formation of glycosidic linkages together with glycoside hydrolases and sugar nucleotide-dependent glycosyltransferases. Noticeably, the catalyzed phosphorolysis is reversible, making phosphorylases suitable ...

  19. Synthesis of Oligosaccharide Fragments of the Pectic Polysaccharide Rhamnogalacturonan I

    DEFF Research Database (Denmark)

    Zakharova, Alexandra

    Pectin is a highly heterogeneous polysaccharide of plant origin. It is found in the primary cell wall and contributes to various cell functions, including support, defense, signaling, and cell adhesion. Pectin also plays important role as a food additive, serving as stabilizing and thickening agent...... in products such as jams, yoghurts and jellies. Rhamnogalacturonan I is one of the structural classes of pectic polysaccharides, along with homogalacturonan and rhamnogalacturonan II. The chemical structure of rhamnogalacturonan I is complex having a backbone consisting of alternating -linked L...

  20. Submillisecond organic synthesis: Outpacing Fries rearrangement through microfluidic rapid mixing.

    Science.gov (United States)

    Kim, Heejin; Min, Kyoung-Ik; Inoue, Keita; Im, Do Jin; Kim, Dong-Pyo; Yoshida, Jun-ichi

    2016-05-01

    In chemical synthesis, rapid intramolecular rearrangements often foil attempts at site-selective bimolecular functionalization. We developed a microfluidic technique that outpaces the very rapid anionic Fries rearrangement to chemoselectively functionalize iodophenyl carbamates at the ortho position. Central to the technique is a chip microreactor of our design, which can deliver a reaction time in the submillisecond range even at cryogenic temperatures. The microreactor was applied to the synthesis of afesal, a bioactive molecule exhibiting anthelmintic activity, to demonstrate its potential for practical synthesis and production. PMID:27151864

  1. Submillisecond organic synthesis: Outpacing Fries rearrangement through microfluidic rapid mixing.

    Science.gov (United States)

    Kim, Heejin; Min, Kyoung-Ik; Inoue, Keita; Im, Do Jin; Kim, Dong-Pyo; Yoshida, Jun-ichi

    2016-05-01

    In chemical synthesis, rapid intramolecular rearrangements often foil attempts at site-selective bimolecular functionalization. We developed a microfluidic technique that outpaces the very rapid anionic Fries rearrangement to chemoselectively functionalize iodophenyl carbamates at the ortho position. Central to the technique is a chip microreactor of our design, which can deliver a reaction time in the submillisecond range even at cryogenic temperatures. The microreactor was applied to the synthesis of afesal, a bioactive molecule exhibiting anthelmintic activity, to demonstrate its potential for practical synthesis and production.

  2. Development of Nanoporous Ni-Sn Alloy and Application for Chemoselective Hydrogenation of Furfural to Furfuryl Alcohol

    Directory of Open Access Journals (Sweden)

    Rodiansono Rodiansono

    2014-03-01

    Full Text Available A very simple synthetic procedure was developed for the preparation of Ni-Sn alloy catalysts that were utilised for chemoselective hydrogenation of furfural, producing furfuryl alcohol almost exclusively. The mixture of nickel nanoparticles supported on aluminium hydroxide (R-Ni/AlOH and a solution containing tin was treated under hydrothermal condition, producing the as prepared nickel-tin alloy supported on aluminium hydroxide (Ni-Sn/AlOH. H2 treatment at range of temperature of 673-873 K for 1.5 h to the as prepared Ni-Sn/AlOH produced nanoporous Ni-Sn alloy catalysts. XRD patterns and SEM images revealed that the formation of Ni-Sn alloy of Ni3Sn and Ni3Sn2 phases and the transformation of crystalline gibbsite and bayerite into amorphous alumina were clearly observed after H2 treatment at 873 K. The formation of the Ni-Sn alloy may have played a key role in the enhancement of the chemoselectivity. © 2014 BCREC UNDIP. All rights reservedReceived: 1st September 2013; Revised: 26th November 2013; Accepted: 7th December 2013[How to Cite: Rodiansono, R., Hara, T., Ichikuni, N., Shimazu, S. (2014. Development of Nanoporous Ni-Sn Alloy and Application for Chemoselective Hydrogenation of Furfural to Furfuryl Alcohol. Bulletin of Chemical Reaction Engineering & Catalysis, 9 (1: 53-59. (doi:10.9767/bcrec.9.1.5529.53-59][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.9.1.5529.53-59

  3. Solid state crystallisation of oligosaccharide ester derivatives

    CERN Document Server

    Wright, E A

    2002-01-01

    An investigation of the solid state properties of oligosaccharide ester derivatives (OEDs) with potential applications in drug delivery has been carried out. The amorphous form of two OEDs, trehalose octa-acetate (TOAC) and 6:6'-di-(beta-tetraacetyl glucuronyl)-hexaacetyl trehalose (TR153), was investigated as a matrix for the sustained release of active ingredients. The matrices showed a tendency to crystallise and so polymorph screens were performed to provide crystalline samples for structural analysis. The crystal structures of TOAC methanolate and TR153 acetonitrile solvate have been determined by single-crystal laboratory X-ray diffraction. TOAC methanolate crystallises in the orthorhombic space group P2 sub 1 2 sub 1 2 sub 1 with a = 15.429(18) A, b = 17.934(19) A and c = 13.518(4) A at 123 K. The structure is isomorphous with the previously reported structure of TOAC monohydrate form II. TR153 acetonitrile solvate crystallises in the monoclinic spacegroup C2 with a = 30:160(6) A, b = 11.878(3) A, c 20...

  4. Evaluation of a Group A Streptococcus synthetic oligosaccharide as vaccine candidate.

    Science.gov (United States)

    Kabanova, Anna; Margarit, Immaculada; Berti, Francesco; Romano, Maria R; Grandi, Guido; Bensi, Giuliano; Chiarot, Emiliano; Proietti, Daniela; Swennen, Erwin; Cappelletti, Emilia; Fontani, Paola; Casini, Daniele; Adamo, Roberto; Pinto, Vittoria; Skibinski, David; Capo, Sabrina; Buffi, Giada; Gallotta, Marilena; Christ, William J; Campbell, A Stewart; Pena, John; Seeberger, Peter H; Rappuoli, Rino; Costantino, Paolo

    2010-12-10

    Bacterial infections caused by Group A Streptococcus (GAS) are a serious health care concern that currently cannot be prevented by vaccination. The GAS cell-wall polysaccharide (GAS-PS) is an attractive vaccine candidate due to its constant expression pattern on different bacterial strains and protective properties of anti-GAS-PS antibodies. Here we report for the first time the immunoprotective efficacy of glycoconjugates with synthetic GAS oligosaccharides as compared to those containing the native GAS-PS. A series of hexa- and dodecasaccharides based on the GAS-PS structure were prepared by chemical synthesis and conjugated to CRM(197). When tested in mice, the conjugates containing the synthetic oligosaccharides conferred levels of immunoprotection comparable to those elicited by the native conjugate. Antisera from immunized rabbits promoted phagocytosis of encapsulated GAS strains. Furthermore we discuss variables that might correlate with glycoconjugate immunogenicity and demonstrate the potential of the synthetic approach that benefits from increased antigen purity and facilitated manufacturing. PMID:20870056

  5. Conformational Analysis of the Oligosaccharides Related to Side Chains of Holothurian Fucosylated Chondroitin Sulfates

    Directory of Open Access Journals (Sweden)

    Alexey G. Gerbst

    2015-02-01

    Full Text Available Anionic polysaccharides fucosylated chondroitin sulfates (FCS from holothurian species were shown to affect various biological processes, such as metastasis, angiogenesis, clot formation, thrombosis, inflammation, and some others. To understand the mechanism of FCSs action, knowledge about their spatial arrangement is required. We have started the systematic synthesis, conformational analysis, and study of biological activity of the oligosaccharides related to various fragments of these types of natural polysaccharides. In this communication, five molecules representing distinct structural fragments of chondroitin sulfate have been studied by means of molecular modeling and NMR. These are three disaccharides and two trisaccharides containing fucose and glucuronic acid residues with one sulfate group per each fucose residue or without it. Long-range C–H coupling constants were used for the verification of the theoretical models. The presence of two conformers for both linkage types was revealed. For the Fuc–GlA linkage, the dominant conformer was the same as described previously in a literature as the molecular dynamics (MD average in a dodechasaccharide FCS fragment representing the backbone chain of the polysaccharide including GalNAc residues. This shows that the studied oligosaccharides, in addition to larger ones, may be considered as reliable models for Quantitative Structure-Activity Relationship (QSAR studies to reveal pharmacophore fragments of FCS.

  6. Homogeneous and heterogeneous photoredox-catalyzed hydroxymethylation of ketones and keto esters: catalyst screening, chemoselectivity and dilution effects

    Directory of Open Access Journals (Sweden)

    Axel G. Griesbeck

    2014-05-01

    Full Text Available The homogeneous titanium- and dye-catalyzed as well as the heterogeneous semiconductor particle-catalyzed photohydroxymethylation of ketones by methanol were investigated in order to evaluate the most active photocatalyst system. Dialkoxytitanium dichlorides are the most efficient species for chemoselective hydroxymethylation of acetophenone as well as other aromatic and aliphatic ketones. Pinacol coupling is the dominant process for semiconductor catalysis and ketone reduction dominates the Ti(OiPr4/methanol or isopropanol systems. Application of dilution effects on the TiO2 catalysis leads to an increase in hydroxymethylation at the expense of the pinacol coupling.

  7. In Vitro fermentability of sugar beet pulp derived oligosaccharides using human and pig fecal inocula

    NARCIS (Netherlands)

    Leijdekkers, A.G.M.; Aguirre, M.; Venema, K.; Bosch, G.; Gruppen, H.; Schols, H.A.

    2014-01-01

    The in vitro fermentation characteristics of different classes of sugar beet pectic oligosaccharides (SBPOS) were studied using human and pig fecal inocula. The SBPOS consisted mainly of partially acetylated rhamnogalacturonan-oligosaccharides and partially methyl esterified/acetylated homogalacturo

  8. Inulin Potential for Enzymatic Obtaining of Prebiotic Oligosaccharides.

    Science.gov (United States)

    Flores, Adriana C; Morlett, Jesús A; Rodríguez, Raúl

    2016-08-17

    Oligosaccharides have been marketed since the 80s as low-calorie agents and recently have gained interest in the pharmaceutical and food industry as functional sweeteners and prebiotic enriching population of Bifidobacteria. Currently, they have an approximated value of $200 per kg and recently, inulin has been proposed as a feedstock for production of oligosaccharides through selective hydrolysis by action of endoinulinase. High optimum temperature (60°C) and thermostability are two important criteria that determine suitability of this enzyme for industrial applications as well as enzyme cost, a major limiting factor. Significant reduction in cost can be achieved by employing low-value and abundant inulin-rich plants as Jerusalem artichoke, dahlia, yacon, garlic, and onion, among others. In general, the early harvested tubers of these plants contain a greater amount of highly polymerized sugar fractions, which offer more industrial value than late-harvested tubers or those after storage. Also, development of recombinant microorganisms could be useful to reduce the cost of enzyme technology for large-scale production of oligosaccharides. In the case of fungal inulinases, several studies of cloning and modification have been made to achieve greater efficiency. The present paper reviews inulin from vegetable sources as feedstock for oligosaccharides production through the action of inulinases, the impact of polymerization degree of inulin and its availability, and some strategies to increase oligosaccharide production.

  9. Inulin Potential for Enzymatic Obtaining of Prebiotic Oligosaccharides.

    Science.gov (United States)

    Flores, Adriana C; Morlett, Jesús A; Rodríguez, Raúl

    2016-08-17

    Oligosaccharides have been marketed since the 80s as low-calorie agents and recently have gained interest in the pharmaceutical and food industry as functional sweeteners and prebiotic enriching population of Bifidobacteria. Currently, they have an approximated value of $200 per kg and recently, inulin has been proposed as a feedstock for production of oligosaccharides through selective hydrolysis by action of endoinulinase. High optimum temperature (60°C) and thermostability are two important criteria that determine suitability of this enzyme for industrial applications as well as enzyme cost, a major limiting factor. Significant reduction in cost can be achieved by employing low-value and abundant inulin-rich plants as Jerusalem artichoke, dahlia, yacon, garlic, and onion, among others. In general, the early harvested tubers of these plants contain a greater amount of highly polymerized sugar fractions, which offer more industrial value than late-harvested tubers or those after storage. Also, development of recombinant microorganisms could be useful to reduce the cost of enzyme technology for large-scale production of oligosaccharides. In the case of fungal inulinases, several studies of cloning and modification have been made to achieve greater efficiency. The present paper reviews inulin from vegetable sources as feedstock for oligosaccharides production through the action of inulinases, the impact of polymerization degree of inulin and its availability, and some strategies to increase oligosaccharide production. PMID:25746219

  10. Glycosyl Thioimidates as Versatile Building Blocks for Organic Synthesis

    Science.gov (United States)

    Hasty, S. J.

    2013-01-01

    This review discusses the synthesis and application of glycosyl thioimidates in chemical glycosylation and oligosaccharide assembly. Although glycosyl thioimidates include a broad range of compounds, the discussion herein centers on S-benzothiazolyl (SBaz), S-benzoxazolyl (SBox), S-thiazolinyl (STaz), and S-benzimidazolyl (SBiz) glycosides. These heterocyclic moieties have recently emerged as excellent anomeric leaving groups that express unique characteristics for highly diastereoselective glycosylation and help to provide the streamlined access to oligosaccharides. PMID:24288416

  11. Beet sugar syrup and molasses as low-cost feedstock for the enzymatic production of fructo-oligosaccharides

    OpenAIRE

    Ghazi, Iraj; Fernández Arrojo, Lucía; Gómez de Segura, María Aránzazu; Alcalde Galeote, Miguel; Plou Gasca, Francisco José; Ballesteros Olmo, Antonio

    2009-01-01

    Sugar syrup and molasses from beet processing containing 620 and 570 mg/ml sucrose, respectively, were assayed as low-cost and available substrates for the enzymatic synthesis of fructo-oligosaccharides (FOS). A commercial pectinase (Pectinex Ultra SP-L, from Aspergillus aculeatus) characterised by the presence of a transfructosylating activity, was used as biocatalyst. The FOS production increased when lowering the initial pH value of syrup (7.5) and molasses (8.9) to 5.5. Sugar syrup and mo...

  12. Novel arabinan and galactan oligosaccharides from dicotyledonous plants

    Science.gov (United States)

    Wefers, Daniel; Tyl, Catrin; Bunzel, Mirko

    2014-11-01

    Arabinans and galactans are neutral pectic side chains and an important part of the cell walls of dicotyledonous plants. To get a detailed insight into their fine structure, various oligosaccharides were isolated from quinoa, potato galactan, and sugar beet pulp after enzymatic treatment. LC-MS2 and one- and two-dimensional NMR spectroscopy were used for unambiguous structural characterization. It was demonstrated that arabinans contain β-(1→3)-linked arabinobiose as a side chain in quinoa seeds, while potato galactan was comprised of β-(1→4)-linked galactopyranoses which are interspersed with α-(1→4)-linked arabinopyranoses. Additionally, an oligosaccharide with two adjacent arabinofuranose units O2-substituted with two ferulic acid monomers was characterized. The isolated oligosaccharides gave further insight into the structures of pectic side chains and may have an impact on plant physiology and dietary fiber fermentation.

  13. Genetic mechanisms of prebiotic oligosaccharide metabolism in probiotic microbes.

    Science.gov (United States)

    Goh, Yong Jun; Klaenhammer, Todd R

    2015-01-01

    Recent insights into the relationship between the human gut and its resident microbiota have revolutionized our appreciation of this symbiosis and its impact on health and disease development. Accumulating evidence on probiotic and prebiotic interventions has demonstrated promising effects on promoting gastrointestinal health by modulating the microbiota toward the enrichment of beneficial microorganisms. However, the precise mechanisms of how prebiotic nondigestible oligosaccharides are metabolized by these beneficial microbes in vivo remain largely unknown. Genome sequencing of probiotic lactobacilli and bifidobacteria has revealed versatile carbohydrate metabolic gene repertoires dedicated to the catabolism of various oligosaccharides. In this review, we highlight recent findings on the genetic mechanisms involved in the utilization of prebiotic fructooligosaccharides, β-galactooligosaccharides, human milk oligosaccharides, and other prebiotic candidates by these probiotic microbes.

  14. Novel arabinan and galactan oligosaccharides from dicotyledonous plants

    Directory of Open Access Journals (Sweden)

    Daniel eWefers

    2014-11-01

    Full Text Available Arabinans and galactans are neutral pectic side chains and an important part of the cell walls of dicotyledonous plants. To get a detailed insight into their fine structure, various oligosaccharides were isolated from quinoa, potato galactan, and sugar beet pulp after enzymatic treatment. LC-MS2 and one- and two-dimensional NMR spectroscopy were used for unambiguous structural characterization. It was demonstrated that arabinans contain β-(1→3-linked arabinobiose as a side chain in quinoa seeds, while potato galactan was comprised of β-(1→4-linked galactopyranoses which are interspersed with α-(1→4-linked arabinopyranoses. Additionally, an oligosaccharide with two adjacent arabinofuranose units O2-substituted with two ferulic acid monomers was characterized. The isolated oligosaccharides gave further insight into the structures of pectic side chains and may have an impact on plant physiology and dietary fiber fermentation.

  15. THE INFLUENCE OF MANNAN OLIGOSACCHARIDES ADDED POLEN ON BRED AREAS

    Directory of Open Access Journals (Sweden)

    OLIMPIA COLIBAR

    2013-07-01

    Full Text Available Probiotics and prebiotics (oligosaccharides and acidifying agents appeared in the place of the old antibiotics. Mannan -oligosaccharides from Saccharomyces cerevisiae (beer-yeast are used with success in the nutrition of pigs, chickens and rabbits. The beer-yeast is used also in the bee family’s foraging with a major success. The bee-bred which is the protein source for the honey bees contains also many species of yeast. Our experiment of adding mannan -oligosaccharides in the energetic and protein feed and of using the artificial bee-bread in the place of pollen shows that those methods didn’t lead an increased performance of the frozen pollen, honey energetic and protein feed.

  16. Overcoming the limited availability of human milk oligosaccharides: challenges and opportunities for research and application.

    Science.gov (United States)

    Bode, Lars; Contractor, Nikhat; Barile, Daniela; Pohl, Nicola; Prudden, Anthony R; Boons, Geert-Jan; Jin, Yong-Su; Jennewein, Stefan

    2016-10-01

    Human milk oligosaccharides (HMOs) are complex sugars highly abundant in human milk but currently not present in infant formula. Rapidly accumulating evidence from in vitro and in vivo studies, combined with epidemiological associations and correlations, suggests that HMOs benefit infants through multiple mechanisms and in a variety of clinical contexts. Until recently, however, research on HMOs has been limited by an insufficient availability of HMOs. Most HMOs are found uniquely in human milk, and thus far it has been prohibitively tedious and expensive to isolate and synthesize them. This article reviews new strategies to overcome this lack of availability by generating HMOs through chemoenzymatic synthesis, microbial metabolic engineering, and isolation from human donor milk or dairy streams. Each approach has its advantages and comes with its own challenges, but combining the different methods and acknowledging their limitations creates new opportunities for research and application with the goal of improving maternal and infant health. PMID:27634978

  17. Overcoming the limited availability of human milk oligosaccharides: challenges and opportunities for research and application.

    Science.gov (United States)

    Bode, Lars; Contractor, Nikhat; Barile, Daniela; Pohl, Nicola; Prudden, Anthony R; Boons, Geert-Jan; Jin, Yong-Su; Jennewein, Stefan

    2016-10-01

    Human milk oligosaccharides (HMOs) are complex sugars highly abundant in human milk but currently not present in infant formula. Rapidly accumulating evidence from in vitro and in vivo studies, combined with epidemiological associations and correlations, suggests that HMOs benefit infants through multiple mechanisms and in a variety of clinical contexts. Until recently, however, research on HMOs has been limited by an insufficient availability of HMOs. Most HMOs are found uniquely in human milk, and thus far it has been prohibitively tedious and expensive to isolate and synthesize them. This article reviews new strategies to overcome this lack of availability by generating HMOs through chemoenzymatic synthesis, microbial metabolic engineering, and isolation from human donor milk or dairy streams. Each approach has its advantages and comes with its own challenges, but combining the different methods and acknowledging their limitations creates new opportunities for research and application with the goal of improving maternal and infant health.

  18. Synthetic oligosaccharides as heparin-mimetics displaying anticoagulant properties.

    Science.gov (United States)

    Avci, Fikri Y; Karst, Nathalie A; Linhardt, Robert J

    2003-01-01

    Heparin and low molecular weight heparins are major clinical anticoagulants and the drugs of choice for the treatment of deep venous thrombosis. The discovery of an antithrombin binding domain in heparin focused interest on understanding the mechanism of heparin's antithrombotic/ anticoagulant activity. Various heparin-mimetic oligosaccharides have been prepared in an effort to replace polydisperse heparin and low molecular weight heparins with a structurally-defined anticoagulant. The goal of attaining a heparin-mimetic with no unwanted side-effects has also provided motivation for these efforts. This article reviews structure-activity relationship (SAR) of structurally-defined heparin-mimetic oligosaccharides. PMID:14529394

  19. An Efficient and Chemoselective Deprotection of tert-Butyldimethylsilyl Protected Alcohols Using SnCl2·2H2O as Catalyst

    Institute of Scientific and Technical Information of China (English)

    Jun HUA; Zhi Yong JIANG; Yan Guang WANG

    2004-01-01

    An efficient and selective method for the deprotection of primary alcoholic tert-butylallow primary alcoholic TBS ethers to be desilylated chemoselectively in the presence of phenolic TBS ethers, secondary and tertiary alcolholic TBS ethers, and the extensively used TBDPS-,acetyl-, benzyloxycarbonyl-, p-toluenesulfonyl- and benzyl protective groups.

  20. Transcriptome profiling of bovine milk oligosaccharide metabolism genes using RNA-sequencing.

    Directory of Open Access Journals (Sweden)

    Saumya Wickramasinghe

    Full Text Available This study examines the genes coding for enzymes involved in bovine milk oligosaccharide metabolism by comparing the oligosaccharide profiles with the expressions of glycosylation-related genes. Fresh milk samples (n = 32 were collected from four Holstein and Jersey cows at days 1, 15, 90 and 250 of lactation and free milk oligosaccharide profiles were analyzed. RNA was extracted from milk somatic cells at days 15 and 250 of lactation (n = 12 and gene expression analysis was conducted by RNA-Sequencing. A list was created of 121 glycosylation-related genes involved in oligosaccharide metabolism pathways in bovine by analyzing the oligosaccharide profiles and performing an extensive literature search. No significant differences were observed in either oligosaccharide profiles or expressions of glycosylation-related genes between Holstein and Jersey cows. The highest concentrations of free oligosaccharides were observed in the colostrum samples and a sharp decrease was observed in the concentration of free oligosaccharides on day 15, followed by progressive decrease on days 90 and 250. Ninety-two glycosylation-related genes were expressed in milk somatic cells. Most of these genes exhibited higher expression in day 250 samples indicating increases in net glycosylation-related metabolism in spite of decreases in free milk oligosaccharides in late lactation milk. Even though fucosylated free oligosaccharides were not identified, gene expression indicated the likely presence of fucosylated oligosaccharides in bovine milk. Fucosidase genes were expressed in milk and a possible explanation for not detecting fucosylated free oligosaccharides is the degradation of large fucosylated free oligosaccharides by the fucosidases. Detailed characterization of enzymes encoded by the 92 glycosylation-related genes identified in this study will provide the basic knowledge for metabolic network analysis of oligosaccharides in mammalian milk. These candidate

  1. Non-digestible oligosaccharides used as prebiotic agents: mode of production and beneficial effects on animal and human health.

    Science.gov (United States)

    Grizard, D; Barthomeuf, C

    1999-01-01

    Prebiotic agents are food ingredients that are potentially beneficial to the health of consumers. The main commercial prebiotic agents consist of oligosaccharides and dietary fibres (mainly inulin). They are essentially obtained by one of three processes: 1) the direct extraction of natural polysaccharides from plants; 2) the controlled hydrolysis of such natural polysaccharides; 3) enzymatic synthesis, using hydrolases and/or glycosyl transferases. Both of these enzyme types catalyse transglycosylation reactions, allowing synthesis of small molecular weight synthetic oligosaccharides from mono- and disaccharides. Presently, in Europe, inulin-type fructans, characterised by the presence of fructosyl units bound to the beta-2,1 position of sucrose, are considered as one of the carbohydrate prebiotic references. Prebiotics escape enzymatic digestion in the upper gastrointestinal tract and enter the caecum without change to their structure. None are excreted in the stools, indicating that they are fermented by colonic flora so as to give a mixture of short-chain fatty acids (acetate, propionate and butyrate), L-lactate, carbon dioxide and hydrogen. By stimulating bifidobacteria, they may have the following implications for health: 1) potential protective effects against colorectal cancer and infectious bowel diseases by inhibiting putrefactive bacteria (Clostridium perfringens ) and pathogen bacteria (Escherichia coli, Salmonella, Listeria and Shigella ), respectively; 2) improvement of glucid and lipid metabolisms; 3) fibre-like properties by decreasing the renal nitrogen excretion; 4) improvement in the bioavailability of essential minerals; and 5) low cariogenic factor. These potential beneficial effects have been largely studied in animals but have not really been proven in humans. The development of a second generation of oligosaccharides and the putative implication of a complex bacterial trophic chain in the intestinal prebiotic fermentation process are also

  2. Effect of oligosaccharides on the growth of Lactobacillus delbrueckii subsp. bulgaricus strains isolated from dairy products.

    Science.gov (United States)

    Ignatova, Tseteslava; Iliev, Ilia; Kirilov, Nikolai; Vassileva, Tonka; Dalgalarrondo, Michèle; Haertlé, Thomas; Chobert, Jean-Marc; Ivanova, Iskra

    2009-10-28

    Eighteen lactic acid bacteria (LAB) strains isolated from dairy products, all identified as Lactobacillus delbrueckii subsp. bulgaricus, were tested for their ability to grow on three different oligosaccharides: fructo-oligosaccharides (FOS), gluco-oligosaccharides (GOS) and galacto-oligosaccharides (GalOS). The growth of LAB on different oligosaccharides was very different. Study of the antimicrobial activities of these LAB indicated that the system of uptake of unusual sugars influenced in a specific way the production of antimicrobial substances (bacteriocins) specific against gram-negative bacteria. The added oligosaccharides induced LAB to form end-products of a typical mixed acid fermentation. The utilization of different types of oligosaccharides may help to explain the ability of Lactobacillus strains to compete with other bacteria in the ecosystem of the human gastro-intestinal tract.

  3. Simultaneous analysis of heparosan oligosaccharides by isocratic liquid chromatography with charged aerosol detection/mass spectrometry.

    Science.gov (United States)

    Ji, Xiaohu; Hu, Guixin; Zhang, Qiongyan; Wang, Fengshan; Liu, Chunhui

    2016-11-01

    Uncovering the biological roles of heparosan oligosaccharides requires a simple and robust method for their separation and identification. We reported on systematic investigations of the retention behaviors of synthetic heparosan oligosaccharides on porous graphitic carbon (PGC) column by HPLC with charged aerosol detection. Oligosaccharides were strongly retained by PGC material in water-acetonitrile mobile phase, and eluted by trifluoroacetic acid occurring as narrow peaks. Addition of small fraction of methanol led to better selectivity of PGC to oligosaccharides than acetonitrile modifier alone, presumably, resulting from displacement of methanol to give different chemical environment at the PGC surface. Van't-Hoff plots demonstrated that retention behaviors highly depended on the column temperature and oligosaccharide moieties. By implementing the optimal MeOH content and temperature, a novel isocratic elution method was successfully developed for baseline resolution and identification of seven heparosan oligosaccharides using PGC-HPLC-CAD/MS. This approach allows for rapid analysis of heparosan oligosaccharides from various sources. PMID:27516280

  4. Extracellular gluco-oligosaccharide degradation by Caulobacter crescentus.

    Science.gov (United States)

    Presley, Gerald N; Payea, Matthew J; Hurst, Logan R; Egan, Annie E; Martin, Brandon S; Periyannan, Gopal R

    2014-03-01

    The oligotrophic bacterium Caulobacter crescentus has the ability to metabolize various organic molecules, including plant structural carbohydrates, as a carbon source. The nature of β-glucosidase (BGL)-mediated gluco-oligosaccharide degradation and nutrient transport across the outer membrane in C. crescentus was investigated. All gluco-oligosaccharides tested (up to celloheptose) supported growth in M2 minimal media but not cellulose or CM-cellulose. The periplasmic and outer membrane fractions showed highest BGL activity, but no significant BGL activity was observed in the cytosol or extracellular medium. Cells grown in cellobiose showed expression of specific BGLs and TonB-dependent receptors (TBDRs). Carbonyl cyanide 3-chlorophenylhydrazone lowered the rate of cell growth in cellobiose but not in glucose, indicating potential cellobiose transport into the cell by a proton motive force-dependent process, such as TBDR-dependent transport, and facilitated diffusion of glucose across the outer membrane via specific porins. These results suggest that C. crescentus acquires carbon from cellulose-derived gluco-oligosaccharides found in the environment by extracellular and periplasmic BGL activity and TBDR-mediated transport. This report on extracellular degradation of gluco-oligosaccharides and methods of nutrient acquisition by C. crescentus supports a broader suite of carbohydrate metabolic capabilities suggested by the C. crescentus genome sequence that until now have not been reported.

  5. Screening Substrate Properties of Microorganisms for Biosensor Detection of Oligosaccharides

    Science.gov (United States)

    Oligosaccharides feature high biological activity ensuring their wide application in the biotechnology, food, and cosmetic industries. On the other hand they are considered environmental pollutants. The study outlines a biosensor approach to detect these substances which is important from above st...

  6. Xylo-oligosaccharides inhibit pathogen adhesion to enterocytes in vitro

    DEFF Research Database (Denmark)

    Ebersbach, Tine; Andersen, Jens Bo; Bergström, Anders;

    2012-01-01

    We previously reported that the non-digestible carbohydrates inulin and apple pectin promoted Listeria monocytogenes infection in guinea pigs, whereas xylo- and galacto-oligosaccharides (XOS and GOS), prevented infection by this pathogen. In the present study, mechanisms that could explain...

  7. Inulin, a flexible oligosaccharide. II : Review of its pharmaceutical applications

    NARCIS (Netherlands)

    Mensink, Maarten A; Frijlink, Henderik W; van der Voort Maarschalk, Kees; Hinrichs, Wouter L J

    2015-01-01

    Inulin is a flexible oligosaccharide which has been used primarily in food for decades. Recently new applications in the pharmaceutical arena were described. In a previous review (Mensink et al. (2015). Carbohydrate Polymers, 130, 405) we described the physicochemical characteristics of inulin, char

  8. Enzymatic production of human milk oligosaccharides

    DEFF Research Database (Denmark)

    Guo, Yao

    as a sialyl donor. This is the first study reporting α-2,6-trans-sialidase activity of this enzyme. Using response surface design allowed identification of two differently optimised conditions for PmST-catalysed production of 3'-sialyllactose and 6'-sialyllactose, giving maximum yields of 2.8 mM and 3.3 m......M from casein glycomacropeptide (9 mM bound sialic acid), respectively. The k cat / K m value for PmST catalysing 6'-sialyllactose synthesis using 3'-sialyllactose as donor was 23.2±0.7 M -1 s -1 . Further, the enzyme was capable of catalysing synthesis of both 3'- and 6'-sialylated...... was almost abolished. The k cat / K m value for PmST P34H catalysing 6'-sialyllactose synthesis using 3'-sialyllactose as donor was 31.2 M -1 s -1 . Moreover, both the wild type enzyme and PmST P34H were capable of catalysing the hydrolysis and transfer of α-2,6 bound sialic acid....

  9. Kinetic analysis of inhibition of glucoamylase and active site mutants via chemoselective oxime immobilization of acarbose on SPR chip surfaces

    DEFF Research Database (Denmark)

    Sauer, Jørgen; Abou Hachem, Maher; Svensson, Birte;

    2013-01-01

    We here report a quantitative study on the binding kinetics of inhibition of the enzyme glucoamylase and how individual active site amino acid mutations influence kinetics. To address this challenge, we have developed a fast and efficient method for anchoring native acarbose to gold chip surfaces...... for surface plasmon resonance studies employing wild type glucoamylase and active site mutants, Y175F, E180Q, and R54L, as analytes. The key method was the chemoselective and protecting group-free oxime functionalization of the pseudo-tetrasaccharide-based inhibitor acarbose. By using this technique we have...... shown that at pH 7.0 the association and dissociation rate constants for the acarbose-glucoamylase interaction are 104M−1s−1 and 103s−1, respectively, and that the conformational change to a tight enzyme–inhibitor complex affects the dissociation rate constant by a factor of 102s−1. Additionally...

  10. Chemoselective Bromodecarboxylation of α-Carboxy-α-cinnamoyl Ketene Cyclic Dithioacetals

    Institute of Scientific and Technical Information of China (English)

    WANG Mang; XU Xian-xiu; LIU Qun; YANG Xiao-xia

    2005-01-01

    @@ Introduction α-Oxoketene dithioacetals(compound 1) are versatile synthons for organic synthesis due to their specially structural characteristic, that is, the masked ketene is conjugated with the convertible carbonyl in their molecules[1-8].

  11. Chitosan and its oligosaccharide derivatives (chito-oligosaccharides) as feed supplements in poultry and swine nutrition.

    Science.gov (United States)

    Swiatkiewicz, S; Swiatkiewicz, M; Arczewska-Wlosek, A; Jozefiak, D

    2015-02-01

    Chitosan is a non-toxic polyglucosamine, widespread in nature, which is deacetylated to varying degrees form of chitin, a component of exoskeleton of shrimps, crabs and insects. Because chitosan contains reactive functional groups, that is, amino acids and hydroxyl groups, it is characterised by antimicrobial, anti-inflammatory, anti-oxidative, antitumor, immunostimulatory and hypocholesterolemic properties when fed as dietary additive for farm animals. This article reviews and discusses the results of studies on the effects of dietary chitosan and its oligosaccharide derivatives on performance and metabolic response in poultry and pigs, that is, haematological, biochemical and immunological blood characteristics, microbiological profile of intestines, intestinal morphology and digestibility of nutrients, as well as on the quality of meat and eggs. The results of most of the experiments presented in this review indicate that chitosan used as a feed additive for poultry and pigs has some beneficial, biological effects, including immunomodulatory, anti-oxidative, antimicrobial and hypocholesterolemic properties. These properties of chitosan, unlike many other kinds of feed additives, were often reflected in improved growth performance (body weight gain and/or feed conversion ratio) of young animals, that is, broiler chickens and weaned pigs. PMID:25041091

  12. Milk Oligosaccharide Variation in Sow Milk and Milk Oligosaccharide Fermentation in Piglet Intestine.

    Science.gov (United States)

    Difilippo, Elisabetta; Pan, Feipeng; Logtenberg, Madelon; Willems, Rianne H A M; Braber, Saskia; Fink-Gremmels, Johanna; Schols, Henk Arie; Gruppen, Harry

    2016-03-16

    Porcine milk oligosaccharides (PMOs) were analyzed in six colostrum and two mature milk samples from Dutch Landrace sows. In total, 35 PMOs were recognized of which 13 were new for the PMO literature: neutral HexNAc-Hex, β4'-galactosyllactose, putative GalNAc(α/β1-3)Gal(β1-4)Glc, lacto-N-fucopentaose-II, lacto-N-tetraose, galactose substituted lacto-N-neohexaose, lacto-N-hexaose and difucosyl-lacto-N-hexaose, and acidic Neu5Ac(α2-6)GlcNAc(β1-3)Gal(β1-4)Glc, sialyllacto-N-tetraose-a and -b, Neu5Ac2-Hex3, and sialyllacto-N-fucopentaose-II. PMOs were analyzed using capillary electrophoresis with laser-induced florescence detection or mass spectrometry and using liquid chromatography with mass spectrometry. Interindividual variation regarding PMO presence and concentration was observed between porcine milks. Within a limited sample set, a 43% decrease of the major PMOs was found during a 1 w lactation period. Interestingly, while some PMOs decreased, some other PMOs increased in concentration. PMOs were also monitored in fecal samples of suckling piglets. In feces of 1-2 d old piglets, few intact PMOs were found, indicating considerable PMO fermentation at early stage of life. PMID:26882005

  13. Radiolabelled oligosaccharide probes: An approach for infection imaging

    International Nuclear Information System (INIS)

    Full text: Aim/Background: Acute gastrointestinal infections due to rotaviruses and other enteric pathogens are major causes of morbidity and mortality in infants and young children throughout the world. The oligosaccharide fraction of human milk bear structural homology to cell surface glycoconjugates and used as receptors by pathogens which protect nursing infants from infections. The similarities between cell surface glycoconjugates and oligosaccharides in human milk strengthen the idea that specific interactions of those oligosaccharides with pathogenic microorganisms do occur preventing the attachment of microbes to epithelial cells. Streptococcus pneumoniae and Haemophilus influenzas are major respiratory pathogens. They attach to the mucosal surfaces of the respiratory tract. This attachment is the first contact with the host tissues and may determine whether the bacteria will colonize the mucosa and cause infection. Conversely, if attachment is inhibited, the infection may be prevented. The free oligosaccharide blocks adhesion. So does human milk, which contains the receptor oligosaccharides. More than 130 lactose-derived oligosaccharides have been identified in human milk. There is the striking evidence that human milk oligosaccharides are potent inhibitors of bacterial adhesion to epithelial surfaces, an initial stage of infective processes. Therefore, these oligosaccharides are considered to be soluble receptor analogues of epithelial cell surfaces participating in the non-immunological defense system of human milk-fed infants. About 130 oligosaccharide complexes have been isolated and characterized from human milk. The presence of oligosaccharides binding proteins (eg.Cym E and Cym B) in bacterial membranes have also been reported. The binding of Streptococcus pneumonia, enteropathogenic E.coli and Haemophilus to their receptors is inhibited by human breast milk oligosaccharides. The binding of oligosaccharides to highly specific recognition receptor

  14. Fructo-oligosaccharides: Production, Purification and Potential Applications.

    Science.gov (United States)

    Bali, Vandana; Panesar, Parmjit S; Bera, Manab B; Panesar, Reeba

    2015-01-01

    The nutritional and therapeutic benefits of prebiotics have attracted the keen interest of consumers and food processing industry for their use as food ingredients. Fructo-oligosaccharides (FOS), new alternative sweeteners, constitute 1-kestose, nystose, and 1-beta-fructofuranosyl nystose produced from sucrose by the action of fructosyltransferase from plants, bacteria, yeast, and fungi. FOS has low caloric values, non-cariogenic properties, and help gut absorption of ions, decrease levels of lipids and cholesterol and bifidus-stimulating functionality. The purified linear fructose oligomers are added to various food products like cookies, yoghurt, infant milk products, desserts, and beverages due to their potential health benefits. This review is focused on the various aspects of biotechnological production, purification and potential applications of fructo-oligosaccharides. PMID:24915337

  15. Inulin, a flexible oligosaccharide. II: Review of its pharmaceutical applications.

    Science.gov (United States)

    Mensink, Maarten A; Frijlink, Henderik W; van der Voort Maarschalk, Kees; Hinrichs, Wouter L J

    2015-12-10

    Inulin is a flexible oligosaccharide which has been used primarily in food for decades. Recently new applications in the pharmaceutical arena were described. In a previous review (Mensink et al. (2015). Carbohydrate Polymers, 130, 405) we described the physicochemical characteristics of inulin, characteristics which make inulin a highly versatile substance. Here, we review its pharmaceutical applications. Applications of inulin that are addressed are stabilization of proteins, modified drug delivery (dissolution rate enhancement and drug targeting), and lastly physiological and disease-modifying effects of inulin. Further uses of inulin include colon specific drug administration and stabilizing and adjuvating vaccine formulations. Overall, the uses of inulin in the pharmaceutical area are very diverse and research is still continuing, particularly with chemically modified inulins. It is therefore likely that even more applications will be found for this flexible oligosaccharide.

  16. Preparation of oligosaccharides from Chinese yam and their antioxidant activity.

    Science.gov (United States)

    Chen, Yi-Feng; Zhu, Qin; Wu, Shengjun

    2015-04-15

    In the present study, the oligosaccharides from Chinese yam were prepared by hydrolysis with hydrogen peroxide (H2O2), which can cleave the glycosidic bonds in polysaccharides. The hydrolysis conditions were optimised by using a central composite design (CCD) as follows: reaction time 4.02 h, temperature 84.35 °C, and H2O2 concentration 2.46%, under which the yield of Chinese yam derived oligosaccharides (CYOs) reached 11.73%, which was consistent with the predicted yield by analysis of the results of CCD (11.89%). The CYOs products were partially characterised by chemical component and Fourier transform infrared spectrum. The CYOs scavenged hydroxyl radical by 89.05% at the concentration of 100 μg/mL, indicating that the CYOs may be a viable option for use as a food antioxidant. PMID:25466131

  17. The chromatographic analysis of oligosaccharides and preparation of 1-kestose and nystose in yacon.

    Science.gov (United States)

    Zhu, Zhen-Yuan; Lian, Hong-Yu; Si, Chuan-Ling; Liu, Yang; Liu, Nian; Chen, Jing; Ding, Li-Na; Yao, Qiang; Zhang, Yongmin

    2012-05-01

    The thin-layer chromatographic analysis of the crude oligosaccharides extracted from yacon revealed the presence of glucose, fructose, sucrose, 1-kestose and nystose. The qualitative and quantitative analysis was carried out on oligosaccharides by high pressure liquid chromatography and the results showed that the contents of d-glucose, fructose, sucrose, 1-kestose, nystose and 1-fructofuranosyl nystose in oligosaccharides were 38.30%, 16.44%, 14.58%, 12.29%, 12.17%, 6.20%, respectively. The content of the fructooligosaccharides in oligosaccharides was 30.66%. The crude oligosaccharides were separated and purified by silica gel column chromatography. The two fractions obtained from crude oligosaccharides were 1-kestose and nystose, which were identified by mass spectra. The yield of 1-kestose and nystose were 10.36% and 9.73%, respectively. The purity of 1-kestose was 82.9% and of nystose was 73.6%. PMID:22013906

  18. Overexpression of a homogeneous oligosaccharide with 13C labeling by genetically engineered yeast strain.

    Science.gov (United States)

    Kamiya, Yukiko; Yamamoto, Sayoko; Chiba, Yasunori; Jigami, Yoshifumi; Kato, Koichi

    2011-08-01

    This report describes a novel method for overexpression of (13)C-labeled oligosaccharides using genetically engineered Saccharomyces cerevisiae cells, in which a homogeneous high-mannose-type oligosaccharide accumulates because of deletions of genes encoding three enzymes involved in the processing pathway of asparagine-linked oligosaccharides in the Golgi complex. Using uniformly (13)C-labeled glucose as the sole carbon source in the culture medium of these engineered yeast cells, high yields of the isotopically labeled Man(8)GlcNAc(2) oligosaccharide could be successfully harvested from glycoprotein extracts of the cells. Furthermore, (13)C labeling at selected positions of the sugar residues in the oligosaccharide could be achieved using a site-specific (13)C-enriched glucose as the metabolic precursor, facilitating NMR spectral assignments. The (13)C-labeling method presented provides the technical basis for NMR analyses of structures, dynamics, and interactions of larger, branched oligosaccharides.

  19. Chemoselective Switch in the Asymmetric Organocatalysis of 5 H -Oxazol-4-ones and N -Itaconimides: Addition-Protonation or [4+2] Cycloaddition

    KAUST Repository

    Zhu, Bo

    2015-12-09

    © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. We report a synthetic strategy for a chemoselective switch and a diastereo-divergent approach for the asymmetric reaction of 5H-oxazol-4-ones and N-itaconimides catalyzed by L-tert-leucine-derived tertiary amine-urea compounds. The reaction was modulated to harness either tandem conjugate addition-protonation or [4+2] cycloaddition as major product with excellent enantio- and diastereoselectivities. Subjecting the enantio-enriched cycloaddition products to a basic silica gel reagent yields the diastereomer vis-à-vis the product directly obtained under conditions for addition-protonation, thus opening a diastereo-divergent route for creating 1,3-tertiary-hetero-quaternary stereocenters. Quantum chemical studies further provide stereochemical analysis for the [4+2] process and a plausible mechanism for this chemoselective switch is proposed.

  20. A New Flavonol Oligosaccharide from the Seeds of Aesculus chinensis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new flavonol oligosaccharide, quercetin-3-O-[b-D-xylopyranosyl-(1?2)- a-L-rhamnopyranosyl-(1?6)]-b-D-glucopyranoside-3¢-O-b-D-glucopyranoside, named aescuflavoside was isolated from Aesculus chinensis. It¢s structure was elucidated by spectra FAB-MS, 1D NMR and 2D NMR including 1H NMR, 13C NMR, HMQC and HMBC techniques.

  1. Galacto-Oligosaccharides : production, properties, applications, and significance as prebiotics

    OpenAIRE

    D. Torres; M. P. Gonçalves; Teixeira, J.A.; Rodrigues, L. R.

    2010-01-01

    Galacto-oligosaccharides (GOS) have now been definitely established as prebiotic ingredients after in vitro and animal and human in vivo studies. Currently, GOS are produced by glycoside hydrolases (GH) using lactose as substrate. Converting lactose into GOS by GH results in mixtures containing GOS of different degrees of polymerization (DP), unreacted lactose, and monomeric sugars (glucose and galactose). Recent and future developments in the production of GOS aim at delivering p...

  2. Human milk oligosaccharides are differentially metabolised in neonatal rats.

    Science.gov (United States)

    Jantscher-Krenn, Evelyn; Marx, Carolin; Bode, Lars

    2013-08-01

    Human milk oligosaccharides (HMO) are complex glycans that are highly abundant in human milk, but not in infant formula. Accumulating data, mostly from in vitro and animal studies, indicate that HMO benefit the breast-fed infant in multiple ways and in different target organs. In vitro incubation studies suggest that HMO can resist the low pH in the infant's stomach and enzymatic degradation in the small intestine and reach the colon in the same composition as in the mother's milk. The oligosaccharide composition in faeces of breast-fed infants is, however, very different from that in the mother's milk, raising questions on when, where and how HMO are metabolised between ingestion and excretion. To answer some of these questions, we established a pulse-chase model in neonatal rats and analysed HMO profiles to track their composition over time in five consecutive equal-length intestinal segments as well as in serum and urine. The relative abundance of individual HMO changed significantly within the first 2 h after feeding and already in the segments of the small intestine prior to reaching the colon. Only 3'-sialyllactose, the major oligosaccharide in rat milk, and hardly any other HMO appeared in the serum and the urine of HMO-fed rats, indicating a selective absorption of rat milk-specific oligosaccharides. The present results challenge the paradigm that HMO reach the colon and other target organs in the same composition as originally secreted with the mother's milk. The present results also raise questions on whether rats and other animals represent suitable models to study the effects of HMO.

  3. Postcolumn HPLC Detection of Mono- and Oligosaccharides with a Chemosensor

    Science.gov (United States)

    Kim, Kyu Kwang; Escobedo, Jorge O.; St. Luce, Nadia N.; Rusin, Oleksandr; Wong, Douglas; Strongin, Robert M.

    2012-01-01

    Novel chromophoric compound 1 promotes the HPLC postcolumn detection of mono- and oligosaccharides. The detection of chromatographic peaks in the visible region for glucose, fructose, maltodextrins, sialic acid, and a ganglioside can be accomplished with a standard UV–vis detector. The use of selective, reversible binding agents in automated HPLC assays should allow for improved monitoring of specific analytes as well as material recovery. PMID:14682751

  4. Structural Determination and Daily Variations of Porcine Milk Oligosaccharides

    OpenAIRE

    Tao, Nannan; Ochonicky, Karen L.; German, J Bruce; Donovan, Sharon M.; Lebrilla, Carlito B.

    2010-01-01

    Free milk oligosaccharides (OS) is a major component of mammalian milk. Swine are important agricultural species and biomedical models. Despite their importance, little is known of the OS profile of porcine milk. Herein, the porcine milk glycome was elucidated and monitored over the entire lactation period by liquid chromatography profiling and structural determination with mass spectrometry. Milk was collected from second parity sows (n=3) at farrowing and on days 1, 4, 7 and 24 of lactation...

  5. Oligosaccharides Affect Performance and Gut Development of Broiler Chickens

    OpenAIRE

    Ao, Z; Choct, M.

    2013-01-01

    The effects of oligosaccharide supplementation on the growth performance, flock uniformity and GIT development of broiler chickens were investigated. Four diets, one negative control, one positive control supplemented with zinc-bacitracin, and two test diets supplemented with mannoligosaccharide (MOS) and fructooligosaccharide (FOS), were used for the experiment. Birds given MOS or FOS had improved body weight (BW) and feed efficiency (FCR), compared to those fed the negative control diet dur...

  6. Rapid detection of malto-oligosaccharide-forming bacterial amylases by high performance anion-exchange chromatography

    DEFF Research Database (Denmark)

    Duedahl-Olesen, Lene; Larsen, K. L.; Zimmermann, W.

    2000-01-01

    High performance anion-exchange chromatography with pulsed amperometric detection was applied for the rapid analysis of malto-oligosaccharides formed by extracellular enzyme preparations from 49 starch-degrading bacterial strains isolated from soil and compost samples. Malto-oligosaccharide-formi......-oligosaccharide-forming amylases, indicated by a predominant formation of maltohexaose from starch, were produced by enzyme preparations from four of the isolates growing at pH 7.0 and 10....

  7. Cellulase-assisted extraction of oligosaccharides from defatted rice bran.

    Science.gov (United States)

    Patindol, J; Wang, L; Wang, Y-J

    2007-11-01

    Defatted rice bran was subjected to cellulase treatment in order to increase its extractable oligosaccharides. Various combinations of enzyme concentration (0%, 0.5%, 1.0%, and 2.0%), temperature (room, 30, 40, and 50 degrees C), and time (1, 3, 5, and 16 h) were tested to identify the optimum extraction conditions. The saccharide content and composition of the extracts were analyzed by high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). Digestibility was assayed in vitro with human salivary and porcine pancreatic alpha-amylases. Extraction yield ranged from 13.4% (without cellulase) to 39.9% (with 2% cellulase). Total carbohydrates, reducing sugars, and crude protein of the dried extracts ranged from 69.2% to 87.2%, 18.7% to 62.3%, and 7.1% to 22.3%, respectively. Mono- and disaccharides constituted more than 50% of the total carbohydrates in the extracts. Inherent oligosaccharides and those produced by cellulolysis made up less than 25%. The in vitro digestibility of the extracts by alpha-amylases was lower compared with that of the original rice bran sample and potato dextrin, which could be attributed to the increased concentrations of oligosaccharides and reducing sugars. PMID:18034713

  8. Novel and Chemoselective Dehydrogenation of 3,4-Dihydropyrimidin-2(1H)-ones with 1,4-Bis(triphenylphosphonium)-2-butene Peroxodisulfate

    Energy Technology Data Exchange (ETDEWEB)

    Gorjizadeh, Maryam [Islamic Azad Univ., Tehran (Iran, Islamic Republic of)

    2013-06-15

    3,4-Dihydropyrimidin-2(1H)-ones were efficiently converted into the corresponding pyrimidin-2(1H)-ones in high yields within a short period of time on treatment with aqueous acetonitrile using 1,4-bis(triphenylphosphonium)-2-butene peroxodisulfate. Chemoselective oxidation of 3,4-dihydropyrimidin in the presence of other oxidizable functional groups was also achieved by this reagent.

  9. Sulfonic acid-functionalized ordered nanoporous Na+-montmorillonite as an efficient, eco-benign, and water-tolerant nanoreactor for chemoselective oxathioacetalization of aldehydes

    Science.gov (United States)

    Shirini, Farhad; Atghia, Seyyed Vahid; Mamaghani, Manouchehr

    2013-01-01

    Sulfonic acid-functionalized ordered nanoporous sodium montmorillonite has been found to be a mild and efficient solid acid catalyst for the chemoselective protection of a variety of carbonyl compounds as oxathiolanes in good to excellent yields. The present method offers several advantages such as short reaction times, high yields, simple procedure and mild conditions. Also, the catalyst could be recycled and reused at least for five times without noticeably decreasing the catalytic activity.

  10. Xyloglucan oligosaccharides promote growth and activate cellulase: Evidence for a role of cellulase in cell expansion

    International Nuclear Information System (INIS)

    Oligosaccharides produced by the action of fungal cellulase on xyloglucans promoted the elongation of etiolated pea (Pisum sativum L.) stem segments in a straight-growth bioassay designed for the determination of auxins. The oligosaccharides were most active at about 1 micromolar. We tested the relative growth-promoting activities of four HPLC-purified oligosaccharides which shared a common glucose4·xylose3 (XG7) core. The substituted oligosaccharides XG8 (glucose4·xylose3·galactose) and XG9n (glucose4·xylose3·galactose2) were more effective than XG7 itself and XG9 (glucose4·xylose3·galactose·fucose). The same oligosaccharides also promoted the degradation, assayed viscometrically, of xyloglucan by an acidic cellulase from bean (Phaseolus vulgaris L.) leaves. The oligosaccharides were highly active at 10-4 molar, causing up to a fourfold increase in activity, but the effect was still detectable at 1 micromolar. Those oligosaccharides (XG8 and XG9n) which best promoted growth, stimulated cellulase activity to the greatest extent. The oligosaccharides did not stimulate the action of the cellulase in an assay based on the conversion of [3H]xyloglucan to ethanol-soluble fragments. This suggests that the oligosaccharides enhanced the midchain hydrolysis of xyloglucan molecules (which would rapidly reduce the viscosity of the solution), at the expense of cleavage near the termini (which would yield ethanol-soluble products)

  11. Asparagine-linked oligosaccharides on lutropin, follitropin, and thyrotropin: distributions of sulfated and sialylated oligosaccharides on bovine, ovine, and human pituitary glycoprotein hormones

    International Nuclear Information System (INIS)

    The asparagine-linked oligosaccharides on the pituitary glycoprotein hormones lutropin (LH), follitropin (FSH), and thyrotropin (TSH) consist of a heterogeneous array of neutral, sulfated, sialylated, and sulfated/sialylated structures. In this study, the authors determined the relative quantities of the various asparagine-linked oligosaccharides on LH, FSH, and TSH from these three animal species. The proportions of sulfated versus sialylated oligosaccharides varied markedly among the different hormones. Both hormone- and animal species-specific differences in the types and distributions of sulfated, sialylated, and sulfated/sialylated structures were evident. In particular, LH and FSH, which are synthesized in the same pituitary cell and bear α-subunits with the identical amino acid sequence, contained significantly different distributions of sulfated and sialylated oligosaccharides. For all three animal species, the ratio of sialylated to sulfated oligosaccharides differed by >10-fold for LH and FSH, with sulfated structures dominating on LH and sialylated structures on FSH. Sialylated oligosaccharides were also heterogeneous with respect to sialic acid linkage (α2,3 versus α2,6). The differences in oligosaccharide structures among the various pituitary glycoprotein hormones as well as among the various glycosylation sites within a single hormone support the hypothesis that glycosylation may serve important functional roles in the expression and/or regulation of hormone bioactivity

  12. Chemical characterization of milk oligosaccharides of the koala (Phascolarctos cinereus).

    Science.gov (United States)

    Urashima, Tadasu; Taufik, Epi; Fukuda, Rino; Nakamura, Tadashi; Fukuda, Kenji; Saito, Tadao; Messer, Michael

    2013-11-01

    Previous structural characterizations of marsupial milk oligosaccharides had been performed in only two macropod species, the tammar wallaby and the red kangaroo. To clarify the homology and heterogeneity of milk oligosaccharides among marsupial species, which could provide information on their evolution, the oligosaccharides of the koala milk carbohydrate fraction were characterized in this study. Neutral and acidic oligosaccharides were separated from the carbohydrate fraction of milk of the koala, a non-macropod marsupial, and characterized by (1)H-nuclear magnetic resonance spectroscopy. The structures of the neutral saccharides were found to be Gal(β1-4)Glc (lactose), Gal(β1-3)Gal(β1-4)Glc (3'-galactosyllactose), Gal(β1-3)Gal(β1-3)Gal(β1-4)Glc (3',3″-digalactosyllactose), Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (lacto-N-novopentaose I) and Gal(β1-3){Gal(β1-4)[Fuc(α1-3)]GlcNAc(β1-6)}Gal(β1-4)Glc (fucosyl lacto-N-novopentaose I), while those of the acidic saccharides were Neu5Ac(α2-3)Gal(β1-4)Glc (3'-SL), Neu5Ac(α2-3)Gal(β1-3)Gal(β1-4)Gal (sialyl 3'-galactosyllactose), Neu5Ac(α2-3)Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (sialyl lacto-N-novopentaose a), Gal(β1-3)[Neu5Ac(α2-6)Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (sialyl lacto-N-novopentaose b), Gal(β1-3)[Neu5Ac(α2-3)Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (sialyl lacto-N-novopentaose c), and Neu5Ac(α2-3)Gal(β1-3){Gal(β1-4)[Fuc(α1-3)]GlcNAc(β1-6)}Gal(β1-4)Glc (fucosyl sialyl lacto-N-novopentaose a). The neutral oligosaccharides, other than fucosyl lacto-N-novopentaose I, a novel hexasaccharide, had been found in milk of the tammar wallaby, a macropod marsupial, while the acidic oligosaccharides, other than fucosyl sialyl lacto-N-novopentaose a had been identified in milk carbohydrate of the red kangaroo. The presence of fucosyl oligosaccharides is a significant feature of koala milk, in which it differs from milk of the tammar wallaby and the red kangaroo.

  13. Biotechnological production of fucosylated human milk oligosaccharides: Prokaryotic fucosyltransferases and their use in biocatalytic cascades or whole cell conversion systems.

    Science.gov (United States)

    Petschacher, Barbara; Nidetzky, Bernd

    2016-10-10

    Human milk oligosaccharides (HMOs) constitute a class of complex carbohydrates unique to mother's milk and are strongly correlated to the health benefits of breastfeeding in infants. HMOs are important as functional ingredients of advanced infant formula and have attracted broad interest for use in health-related human nutrition. About 50% of the HMOs structures contain l-fucosyl residues, which are introduced into nascent oligosaccharides by enzymatic transfer from GDP-l-fucose. To overcome limitation in the current availability of fucosylated HMOs, biotechnological approaches for their production have been developed. Functional expression of the fucosyltransferase(s) and effective supply of GDP-l-fucose, respectively, are both bottlenecks of the biocatalytic routes of synthesis. Strategies of in vitro and in vivo production of fucosylated HMOs are reviewed here. Besides metabolic engineering for enhanced HMO production in whole cells, the focus is on the characteristics and the heterologous overexpression of prokaryotic α1,2- and α1,3/4-fucosyltransferases. Up to 20g/L of fucosylated HMOs were obtained in optimized production systems. Optimized expression enabled recovery of purified fucosyltransferases in a yield of up to 45mg/L culture for α1,2-fucosyltransferases and of up to 200mg protein/L culture for α1,3/4-fucosyltransferases.

  14. Synthesis of Heterocyclic Ring Systems Using Organometallic Reagents

    Institute of Scientific and Technical Information of China (English)

    Sameer Agarwal; Jan Kn(o)ll; Micha P. Krahl; Hans-Joachim Kn(o)lker

    2005-01-01

    @@ 1Introduction We developed novel synthetic routes to heterocyclic ring systems by using transition metal-mediated or -catalyzed reactions. A Lewis acid-promoted addition of the propargyl Grignard reagent 2 to the Schiff base 1 followed by a silvermediated oxidative cyclization of the homopropargylamine 3 provided the aryl-substituted pyrrole 4. Combined with a chemoselective hydrogenation of the pyrrole ring, this method has been applied to the total synthesis of the biologically active fused indolizidine alkaloids ( ± )-harmicine and ( ± )-crispine A[1]. See Fig. 1.

  15. A Pot-Economical Approach to the Total Synthesis of Sch-725674.

    Science.gov (United States)

    Bodugam, Mahipal; Javed, Salim; Ganguly, Arghya; Torres, Jessica; Hanson, Paul R

    2016-02-01

    A pot-economical total synthesis of antifungal Sch-725674, 1, is reported. The approach takes advantage of a number of one-pot, sequential transformations, including a phosphate tether-mediated one-pot, sequential RCM/CM/chemoselective hydrogenation protocol, a one-pot tosylation/acrylation sequence, and a one-pot, sequential Finkelstein reaction/Boord olefination/acetonide deprotection procedure to streamline the synthesis route by reducing isolation and purification procedures, thus saving time. Overall, an asymmetric route has been developed that is efficiently accomplished in seven pots from phosphate (S,S)-triene and with minimal purification. PMID:26760683

  16. A Convergent Solid-Phase Synthesis of Actinomycin Analogues - Towards Implementation of Double-Combinatorial Chemistry

    DEFF Research Database (Denmark)

    Tong, Glenn; Nielsen, John

    1996-01-01

    with the requirements for combinatorial synthesis and furthermore, the final segment condensation allows, for the first time, double-combinatorial chemistry to be performed where two combinatorial libraries can be reacted with each other. Copyright (C) 1996 Elsevier Science Ltd....... of peptide-aryl-peptide conjugates modeled upon natural actinomycins. The features of this method include the use of Fmoc solid-phase peptide synthesis, side-chain to side-chain cyclization on the solid phase, a chemoselective cleavage step and segment condensation. The synthetic scheme is consistent...

  17. In Vitro Determination of Prebiotic Properties of Oligosaccharides Derived from an Orange Juice Manufacturing By-Product Stream

    OpenAIRE

    Manderson, K.; Pinart, M.; Tuohy, K. M.; Grace, W. E.; Hotchkiss, A T; Widmer, W.; Yadhav, M. P.; Gibson, G R; Rastall, R. A.

    2005-01-01

    Fermentation properties of oligosaccharides derived from orange peel pectin were assessed in mixed fecal bacterial culture. The orange peel oligosaccharide fraction contained glucose in addition to rhamnogalacturonan and xylogalacturonan pectic oligosaccharides. Twenty-four-hour, temperature- and pH-controlled, stirred anaerobic fecal batch cultures were used to determine the effects that oligosaccharides derived from orange products had on the composition of the fecal microbiota. The effects...

  18. Understanding the fundamental mechanism behind accumulation of oligosaccharides during high solids loading enzymatic hydrolysis

    Science.gov (United States)

    During enzymatic hydrolysis of biomass, polysaccharides are cleaved by glycosyl hydrolases to soluble oligosaccharides and further hydrolyzed by ß-glucosidase, ß-xylosidase and other enzymes to monomeric sugars. However, commercial enzyme mixtures do not hydrolyze all of these oligosaccharides and v...

  19. Enzymatic production and purification of prebiotic oligosaccharides by chromatography and membrane systems

    DEFF Research Database (Denmark)

    Michalak, Malwina

    , maltose, and fucose were sialylated with this enzyme resulting in creating novel human milk-like oligosaccharides. Both HMO and human milk- like oligosaccharides were purified by filtration and chromatography. The last compounds produced during this study were GOS and some galactopolysaccharides...

  20. Rational design of anticoagulant drugs using oligosaccharide chemistry.

    Science.gov (United States)

    El Hadri, Ahmed; Petitou, Maurice

    2011-01-01

    For a long time, heparin and low molecular weight heparins have been the drugs of choice for the management of thrombosis. Discovery of the antithrombin binding domain in heparin, a critical element in the anticoagulant activity of this polysaccharide, allowed a rational approach based on medicinal carbohydrate chemistry in the design of new anticoagulants. The fully synthetic pentasaccharide fondaparinux that selectively targets blood coagulation factor Xa was first to be developed as a drug. Fondaparinux was followed by various heparin mimicking oligosaccharides prepared with a view to replace polydisperse heparin and low molecular weight heparins by structurally-defined anticoagulants with no unwanted side-effects. PMID:21469438

  1. Computational models explain the oligosaccharide specificity of cyanovirin-N

    OpenAIRE

    Fujimoto, Yukiji K.; TerBush, Ryan N.; Patsalo, Vadim; Green, David F.

    2008-01-01

    The prokaryotic lectin cyanovirin-N (CV-N) is a potent inhibitor of HIV envelope-mediated cell entry, and thus is a leading candidate among a new class of potential anti-HIV microbicides. The activity of CV-N is a result of interactions with the D1 arm of high-mannose oligosaccharides on the viral glycoprotein gp120. Here, we present computationally refined models of CV-N recognition of the di- and trisaccharides that represent the terminal three sugars of the D1 arm by each CV-N binding site...

  2. Mannose-6-phosphate regulates destruction of lipid-linked oligosaccharides

    OpenAIRE

    Gao, Ningguo; Shang, Jie; Huynh, Dang; Manthati, Vijaya L.; Arias, Carolina; Harding, Heather P.; Kaufman, Randal J.; Mohr, Ian; Ron, David; Falck, John R.; Lehrman, Mark A.

    2011-01-01

    Mannose-6-phosphate (M6P) is an essential precursor for mannosyl glycoconjugates, including lipid-linked oligosaccharides (LLO; glucose3mannose9GlcNAc2-P-P-dolichol) used for protein N-glycosylation. In permeabilized mammalian cells, M6P also causes specific LLO cleavage. However, the context and purpose of this paradoxical reaction are unknown. In this study, we used intact mouse embryonic fibroblasts to show that endoplasmic reticulum (ER) stress elevates M6P concentrations, leading to clea...

  3. Oligosaccharide binding to barley alpha-amylase 1

    DEFF Research Database (Denmark)

    Robert, X.; Haser, R.; Mori, H.;

    2005-01-01

    Enzymatic subsite mapping earlier predicted 10 binding subsites in the active site substrate binding cleft of barley alpha-amylase isozymes. The three-dimensional structures of the oligosaccharide complexes with barley alpha-amylase isozyme 1 (AMY1) described here give for the first time a thorough...... in barley alpha-amylase isozyme 2 (AMY2), and the sugar binding modes are compared between the two isozymes. The "sugar tongs" surface binding site discovered in the AMY1-thio-DP4 complex is confirmed in the present work. A site that putatively serves as an entrance for the substrate to the active site...

  4. NMR structural studies of oligosaccharides and other natural products

    DEFF Research Database (Denmark)

    Kjærulff, Louise

    depsipeptides capable of attenuating virulence in S. aureus by quorum sensing inhibition through the accessory gene regulator agr. This is likely due to their structural similarities with the auto-inducing peptides of S. aureus, controlling quorum sensing in bacterial populations. A filamentous fungus, A...... found in human milk are important for infant nutrition, and a collaborative effort of university and industry partners was aimed at establishing methods for production of human milk oligosaccharides. Two different bioenzymatic methods for production of 3’-sialyllactose were investigated, and a screening...

  5. Core Oligosaccharide of Plesiomonas shigelloides PCM 2231 (Serotype O17 Lipopolysaccharide — Structural and Serological Analysis

    Directory of Open Access Journals (Sweden)

    Anna Maciejewska

    2013-02-01

    Full Text Available The herein presented complete structure of the core oligosaccharide of lipopolysaccharide (LPS P. shigelloides Polish Collection of Microorganisms (PCM 2231 (serotype O17 was investigated by 1H, 13C NMR spectroscopy, mass spectrometry, chemical analyses and serological methods. The core oligosaccharide is composed of an undecasaccharide, which represents the second core type identified for P. shigelloides serotype O17 LPS. This structure is similar to that of the core oligosaccharide of P. shigelloides strains 302-73 (serotype O1 and 7-63 (serotype O17 and differs from these only by one sugar residue. Serological screening of 55 strains of P. shigelloides with the use of serum against identified core oligosaccharide conjugated with bovine serum albumin (BSA indicated the presence of similar structures in the LPS core region of 28 O-serotypes. This observation suggests that the core oligosaccharide structure present in strain PCM 2231 could be the most common type among P. shigelloides lipopolysaccharides.

  6. Production of agaro- and carra-oligosaccharides by partial acid hydrolysis of galactans

    Directory of Open Access Journals (Sweden)

    Diogo R. B. Ducatti

    2011-04-01

    Full Text Available Agaro- and carra-oligosaccharides were produced by partial acid hydrolysis of commercial agarose and kappa-carrageenan. Di- and tetrasaccharides were purified by gel filtration chromatography and characterized by NMR (1D and 2D spectroscopy and ESIMS. The following oligosaccharides were obtained: agarobiose, agarotetraose, kappa-carrabiose and kappa-carratetraose. Agarobiose and agarotetraose were used as standards to develop a high performance size exclusion chromatography (HPSEC method which was utilized to study the hydrolysis rate of agarose and oligosaccharide production. Six hours of hydrolysis (0.1 M TFA, 65 ºC produced mainly di- and tetrasaccharides. The methodology for oligosaccharide production and evaluation developed in the present work shows good potential for the production of bioactive oligosaccharides.

  7. Effects of supplemental fructo-oligosaccharide and mannan-oligosaccharide on nutrient digestibilities, volatile fatty acid concentrations, and immune function in horses

    OpenAIRE

    GÜRBÜZ, Emel; İNAL, Fatma; ATA, Sakine Ülküm; ÇİTİL, Özcan Barış

    2010-01-01

    This research was performed to study the effects of fructo-oligosaccharide (FOS) and mannan-oligosaccharide (MOS) on nutrient digestibilities, fecal pH and volatile fatty acids compositions, and immune function in adult horses. Four adult Thoroughbred horses were used in a 4×4 Latin Square design with 20-day treatment periods. A 12-day adaptation phase was followed by 6-day collection of feces and 2-day blood sampling phases. Four different treatments were administered: 1) Control (no supplem...

  8. Magnetic removal of Entamoeba cysts from water using chitosan oligosaccharide-coated iron oxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Shukla S

    2015-07-01

    Full Text Available Sudeep Shukla,1 Vikas Arora,2 Alka Jadaun,3 Jitender Kumar,1 Nishant Singh,1 Vinod Kumar Jain1 1School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, Delhi, India; 2Department of Chemistry, Indian Institute of Technology, New Delhi, Delhi, India; 3School of Biotechnology, Jawaharlal Nehru University, New Delhi, Delhi, India Abstract: Amebiasis, a major health problem in developing countries, is the second most common cause of death due to parasitic infection. Amebiasis is usually transmitted by the ingestion of Entamoeba histolytica cysts through oral–fecal route. Herein, we report on the use of chitosan oligosaccharide-functionalized iron oxide nanoparticles for efficient capture and removal of pathogenic protozoan cysts under the influence of an external magnetic field. These nanoparticles were synthesized through a chemical synthesis process. The synthesized particles were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and zeta potential analysis. The particles were found to be well dispersed and uniform in size. The capture and removal of pathogenic cysts were demonstrated by fluorescent microscopy, transmission electron microscopy, and scanning electron microscopy (SEM. Three-dimensional modeling of various biochemical components of cyst walls, and thereafter, flexible docking studies demonstrate the probable interaction mechanism of nanoparticles with various components of E. histolytica cyst walls. Results of the present study suggest that E. histolytica cysts can be efficiently captured and removed from contaminated aqueous systems through the application of synthesized nanoparticles. Keywords: amebiasis, water treatment, nanotechnology

  9. Magnetic removal of Entamoeba cysts from water using chitosan oligosaccharide-coated iron oxide nanoparticles.

    Science.gov (United States)

    Shukla, Sudeep; Arora, Vikas; Jadaun, Alka; Kumar, Jitender; Singh, Nishant; Jain, Vinod Kumar

    2015-01-01

    Amebiasis, a major health problem in developing countries, is the second most common cause of death due to parasitic infection. Amebiasis is usually transmitted by the ingestion of Entamoeba histolytica cysts through oral-fecal route. Herein, we report on the use of chitosan oligosaccharide-functionalized iron oxide nanoparticles for efficient capture and removal of pathogenic protozoan cysts under the influence of an external magnetic field. These nanoparticles were synthesized through a chemical synthesis process. The synthesized particles were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and zeta potential analysis. The particles were found to be well dispersed and uniform in size. The capture and removal of pathogenic cysts were demonstrated by fluorescent microscopy, transmission electron microscopy, and scanning electron microscopy (SEM). Three-dimensional modeling of various biochemical components of cyst walls, and thereafter, flexible docking studies demonstrate the probable interaction mechanism of nanoparticles with various components of E. histolytica cyst walls. Results of the present study suggest that E. histolytica cysts can be efficiently captured and removed from contaminated aqueous systems through the application of synthesized nanoparticles.

  10. Phytic acid and raffinose series oligosaccharides metabolism in developing chickpea seeds.

    Science.gov (United States)

    Zhawar, Vikramjit Kaur; Kaur, Narinder; Gupta, Anil Kumar

    2011-10-01

    Phytic acid and raffinose series oligosaccharides (RFOs) have anti-nutritional properties where phytic acid chelates minerals and reduces their bioavailability to humans and other animals, and RFOs cause flatulence. Both phytic acid and RFOs cannot be digested by monogastric animals and are released as pollutant-wastes. Efforts are being made to reduce the contents of these factors without affecting the viability of seeds. This will require a thorough understanding of their metabolism in different crops. Biosynthetic pathways of both metabolites though are interlinked but not well described. This study was made on metabolism of these two contents in developing chickpea (Cicer arietinum L cv GL 769) seeds. In this study, deposition of RFOs was found to occur before deposition of phytic acid. A decline in inorganic phosphorus and increase in phospholipid phosphorus and phytic acid was observed in seeds during development. Acid phosphatase was the major phosphatase in seed as well as podwall and its activity was highest at early stage of development, thereafter it decreased. Partitioning of (14) C label from (14) C-glucose and (14) C-sucrose into RFOs and phytic acid was studied in seeds in presence of inositol, galactose and iositol and galactose, which favored the view that galactinol synthase is not the key enzyme in RFOs synthesis.

  11. Comparative and genetic analyses of the putative Vibrio cholerae lipopolysaccharide core oligosaccharide biosynthesis (wav) gene cluster.

    Science.gov (United States)

    Nesper, Jutta; Kraiss, Anita; Schild, Stefan; Blass, Julia; Klose, Karl E; Bockemühl, Jochen; Reidl, Joachim

    2002-05-01

    We identified five different putative wav gene cluster types, which are responsible for the synthesis of the core oligosaccharide (OS) region of Vibrio cholerae lipopolysaccharide. Preliminary evidence that the genes encoded by this cluster are involved in core OS biosynthesis came from analysis of the recently released O1 El Tor V. cholerae genome sequence and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of O1 El Tor mutant strains defective in three genes (waaF, waaL, and wavB). Investigations of 38 different V. cholerae strains by Southern blotting, PCR, and sequencing analyses showed that the O1 El Tor wav gene cluster type is prevalent among clinical isolates of different serogroups associated with cholera and environmental O1 strains. In contrast, we found differences in the wav gene contents of 19 unrelated non-O1, non-O139 environmental and human isolates not associated with cholera. These strains contained four new wav gene cluster types that differ from each other in distinct gene loci, providing evidence for horizontal transfer of wav genes and for limited structural diversity of the core OS among V. cholerae isolates. Our results show genetic diversity in the core OS biosynthesis gene cluster and predominance of the type 1 wav gene locus in strains associated with clinical cholera, suggesting that a specific core OS structure could contribute to V. cholerae virulence.

  12. Transglutaminase catalyzed hydrolyzed wheat gliadin grafted with chitosan oligosaccharide and its characterization.

    Science.gov (United States)

    Jiang, Wen; Zhou, Zhiming; Wang, Dan; Zhou, Xiaohua; Tao, Renyou; Yang, Yang; Shi, Yexin; Zhang, Guiluo; Wang, Deyi; Zhou, Zhen

    2016-11-20

    Chitosan oligosaccharide (COS) was grafted on hydrolyzed wheat gliadin (HWG) with microbial transglutaminase (MTGase) as catalyst. The grafting reaction exhibited the best performance when it was done under the optimum temperature 50°C for 50min with HWG/COS mass ratio of 40:1, pH 6.00-6.50. The maximum grafting rate of COS was 64.83% at this condition. The chemical structure characterizations of HWG-COS performed by FTIR, (13)C NMR, X-ray diffractometry and TGA-DTG illustrated that amino groups in COS had participated in the formations of the amino band during the synthesis. HPLC and GFC analysis showed that HWG-COS had two main components, which together accounted for 80.64% of the total polymer and the molecular weight of the two components was 61.77kDa and 27.29kDa, respectively. HWG-COS was undissolved in water and many organic solvent, slightly soluble in 1% NaOH, with a solubility of 1.84mg/L. In antibacterial activity test, HWG-COS showed the best antimicrobial properties to Salmonella enteriditis, with an antibacterial activity improved by 41.74%. PMID:27561477

  13. Nitric Oxide Potentiates Oligosaccharide-induced Artemisinin Production in Artemisia annua Hairy Roots

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The purpose of the present study was to characterize the generation of nitric oxide (NO) in Artemisia annua roots induced by an oligosaccharide elicitor (OE) from Fusarium oxysporum mycelium and the potentiation role of NO in the elicitation of artemisinin accumulation. The OE (0.3 mg total sugar/mL) induced a rapid production of NO in cultures, which exhibited a biphasic time course, reaching the first plateau within 1.5 h and the second within 8 h of OE treatment. Artemisinin content in 20-day-old hairy roots was increased from 0.7 mg/g dry wt to 1.3 mg/g dry wt by using the OE treatment for 4d. In the absence of OE, the NO donor sodium nitroprusside (SNP) at 10, 50 μM and 100 μM enhanced the growth of hairy roots, but had no effect on artemisinin synthesis. The combination of SNP with OE increased artemisinin content from 1.2 mg/g dry wt to 2.2 mg/g dry wt, whereas the maximum production of artemisinin in cultures was 28.5 mg/L, a twofold increase over the OE treatment alone. The effects of SNP on the OE-induced artemisinin were suppressed strongly by the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO). The results suggest that NO can strongly potentiate elicitor-induced artemisinin synthesis in A. annua hairy roots.

  14. Esterificación quimioselectiva de fitosteroles de madera mediante lipasas Chemoselective transesterification of wood steroles by lipases

    Directory of Open Access Journals (Sweden)

    Álvaro Gregorio

    2008-07-01

    estanol; enzima inmovilizadaThe chemoselective transesterification of wood sterols is a novel type application of lipases that is considered within a technological platform for the upgrading of black liquor from the Kraft pulping process. Wood sterols are a mixture of sterols and stanols (saturated sterols in which more than 90% is represented by β-sitosterol and β-sitostanol. Both products are oriented to different markets, representing the fractionation of the wood sterols a significant added value. Both substances are structurally similar which precludes its separation by physical operations, being its fractionation by chemoselective esterification with lipases a very appealing strategy. Several commercial lipases were evaluated in their capacity for the selective transesterification of stanols and two of them were selected: one immobilized and one non-supported. The process was optimized with the immobilized lipase obtaining more than 90% esterification of sterols with around 20% esterification of sterols, which satisfied the criterion of selectivity. The immobilized enzyme was however poorly stable because of protein desorption during the reaction; therefore, several strategies of immobilization of the non-supported lipase were developed, best results being obtained with butyl Sepabeads® as support. The selected biocatalyst was tested in the sequential batch reaction of transesterification, proving that the biocatalyst can be used for five sequential batches with very little loss of activity and insignificant reduction in conversion and productivity, which satisfies the profitability criterion of the process. Key words: Lipase; enzymatic transesterification; wood sterols; stanol esters; immobilized enzyme.

  15. Study of TiO2 nanoparticle phase alteration and its catalytic effect on the chemoselective -sulphonylation of amines and urazoles

    Indian Academy of Sciences (India)

    Davood Azarifar; Fatemeh Soleimanei; Babak Jaleh

    2013-07-01

    Anatase and rutile are the two major crystalline phases of TiO2. Heat treatment can change crystal structure and physical properties of TiO2 nanoparticles. The effect of particles size on anatase-rutile phase transformation has been studied for the -sulphonylation of amines and urazoles both under the conventional and ultrasound irradiation conditions. The main advantages allocated to this method are chemoselectivity, reduced reaction times, high yield, non-solvent green conditions and easy procedure. The catalyst can be easily recovered simply by filtration and reused with no significant loss in its reactivity.

  16. Ionic liquid-H2O Resulting in a Highly Chemoselective Oxidation of Benzylic Alcohols in the Presence of Aliphatic Analogues Catalyzed by Immobilized TEMPO

    Institute of Scientific and Technical Information of China (English)

    HU,Ruijun; LEI,Ming; WEI,Hegeng; WANG,Yanguang

    2009-01-01

    In ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate([bmim][PF6])-H2O,a highly chemoselective oxidation of benzylic alcohols in the presence of aliphatic ones to the corresponding hydroxyl benzyl aldehydes and ketones was allowed in high yields using N-chlorosuccinimide(NCS)/NaBr/IL-TEMPO(ionic liquid immobilized 2,2,6,6-tetramethylpiperidine-1-oxyl)as a facile and effective catalytic oxidation system.The medium,[bmiml[PF6],together with the catalyst IL-TEMPO could be easily recycled for ten runs without any influence on the efficacy of the reaction in terms of yield and selectivity of the product.

  17. ZrOCl2 Catalysed Chemoselective Conversion of Aldehydes to geminal-Diacetates and Their Cleavage: A Mild and Efficient Method

    Institute of Scientific and Technical Information of China (English)

    NAGARAJ, Adki; SANJEEVA REDDY,Cherkupally

    2007-01-01

    ZrOCl2 was found to be an effective Lewis acid catalyst for the solventless chemoselective conversion of aldehydes into geminal-diacetates in high yields at room temperature. Regeneration of the aldehydes from the acetals was also achieved using the same catalyst in water. The beneficial effect of microwave irradiation on the reaction was also described. Other advantages are the very low loading of catalyst, high yields achieved even on a gram scale, and considerably shortened reaction time compared to the conventional method.

  18. Enhancing Metal-Support Interactions by Molybdenum Carbide: An Efficient Strategy toward the Chemoselective Hydrogenation of α,β-Unsaturated Aldehydes.

    Science.gov (United States)

    He, Sina; Shao, Zheng-Jiang; Shu, Yijin; Shi, Zhangping; Cao, Xiao-Ming; Gao, Qingsheng; Hu, Peijun; Tang, Yi

    2016-04-11

    Metal-support interactions are desired to optimize the catalytic turnover on metals. Herein, the enhanced interactions by using a Mo2 C nanowires support were utilized to modify the charge density of an Ir surface, accomplishing the selective hydrogenation of α,β-unsaturated aldehydes on negatively charged Ir(δ-) species. The combined experimental and theoretical investigations showed that the Ir(δ-) species derive from the higher work function of Ir (vs. Mo2 C) and the consequently electron transfer. In crotonaldehyde hydrogenation, Ir/Mo2 C delivered a crotyl alcohol selectivity as high as 80 %, outperforming those of counterparts (competitive for chemoselective hydrogenation. PMID:26934305

  19. Oligosaccharides and glycolipids addition in charged lamellar phases; Addition d`oligosaccharides et de glycolipides dans des phases lamellaires chargees

    Energy Technology Data Exchange (ETDEWEB)

    Ricoul, F

    1997-09-26

    The aim of this work is to study the addition of oligosaccharides and glycolipids in lamellar phases of the cationic surfactant DDAB (di-dodecyl-dimethyl-ammonium bromide). Two steps have been followed: the determination of phases prisms and the thermodynamic interpretation in terms of molecular interactions. In order to characterize these systems, two new experimental small angle scattering methods have been perfected: 1) a neutron scattering contrast variation method which allows to study the adsorption of aqueous solution in bilayers and 2) a capillary concentration gradient method to establish directly and quantitatively the phases diagrams of ternary systems by X rays scattering. It has been pointed out that the oligosaccharides induce a depletion attractive force on the lamellar-lamellar equilibrium of the DDAB when they are excluded of the most concentrated phase. For the two studied glycolipids: 2-O lauroyl-saccharose and N-lauroyl N-nonyl lactitol, the ternary phase diagrams water-DDAB-glycolipid have been established in terms of temperature. Critical points at ambient temperature have been given. The osmotic pressure in concentrated lamellar phases has been measured. It has been shown that glycolipids increase the hydration repulsion at short distance and that the electrostatic repulsion is outstanding and unchanged at high distance if there is at less 1 mole percent of ionic surfactant. In a dilute solution, glycolipids decrease the maximum swelling of lamellar phases, with a competition between the lamellar phase and the micellae dilute phase for water. (O.M.). 165 refs.

  20. Comparative structural study of N-linked oligosaccharides of urinary and recombinant erythropoietins

    Energy Technology Data Exchange (ETDEWEB)

    Tsuda, E.; Goto, M.; Murakami, A.; Akia, K.; Ueda, M.; Kawanishi, G.; Takahashi, N.; Sasaki, R.; Chiba, H.; Ishihara, H.; Mori, M.

    1988-07-26

    The structures of the N-linked oligosaccharides of the urinary erythropoietin (u-EPOI) purified from urine of aplastic anemic patients were analyzed and compared with those for recombinant erythropoietin (r-EPO) prepared with baby hamster kidney (BHK) cells. Asparagine-linked neutral oligosaccharides were released from each EPO protein by N-oligosaccharide glycopeptidase (almond) digestion. The reducing ends of the oligosaccharide chains thus obtained were aminated with a fluorescent reagent, 2-aminopyridine, and the mixture of pyridylamino derivatives of the oligosaccharides was separated by high-performance liquid chromatography (HPLC) on an ODS silica column. More than 8 and 13 kinds of oligosaccharide fractions for u-EPO and r-EPO (BHK), respectively, were completely separated by the one-step HPLC procedure. The structure of each oligosaccharide thus isolated was analyzed by a combination of sequential exoglycosidase digestion and another kind of HPLC with an amide-silica column. Furthermore, high-resolution proton nuclear magnetic resonance (/sup 1/H NMR) spectroscopy and methylation analyses were carried out in the case of r-EPO (BHK).

  1. Mass spectrometric analysis of O-linked oligosaccharides from various recombinant expression systems.

    Science.gov (United States)

    Kenny, Diarmuid T; Gaunitz, Stefan; Hayes, Catherine A; Gustafsson, Anki; Sjöblom, Magnus; Holgersson, Jan; Karlsson, Niclas G

    2013-01-01

    Analysis of O-linked glycosylation is one of the main challenges during structural validation of recombinant glycoproteins. With methods available for N-linked glycosylation in regard to oligosaccharide analysis as well as glycopeptide mapping, there are still challenges for O-linked glycan analysis. Here, we present mass spectrometric methodology for O-linked oligosaccharides released by reductive β-elimination. Using LC-MS and LC-MS(2) with graphitized carbon columns, oligosaccharides are analyzed without derivatization. This approach provides a high-throughput method for screening during clonal selection, as well as product structure verification, without impairing sequencing ability. The protocols are exemplified by analysis of glycoproteins from mammalian cell cultures (CHO cells) as well as insect cells and yeast. The data shows that the method can be successfully applied to both neutral and acidic O-linked oligosaccharides, where sialic acid, hexuronic acid, and sulfate are common substituents. Further characterization of O-glycans can be achieved using permethylation. Permethylation of O-linked oligosaccharides followed by direct infusion into the mass spectrometer provide information about oligosaccharide composition, and subsequent MS (n) experiments can be carried out to elucidate oligosaccharide structure including linkage information and sequence.

  2. Application of ultrasound for enhanced extraction of prebiotic oligosaccharides from selected fruits and vegetables.

    Science.gov (United States)

    Jovanovic-Malinovska, Ruzica; Kuzmanova, Slobodanka; Winkelhausen, Eleonora

    2015-01-01

    Ultrasound assisted extraction (UAE) was used to extract oligosaccharides from selected fruits (blueberry, nectarine, raspberry, watermelon) and vegetables (garlic, Jerusalem artichoke, leek, scallion, spring garlic and white onion). The individual fractions of the oligosaccharides were analyzed: 1-kestose (GF2), nystose (GF3) and 1F-β-fructofuranosylnystose (GF4) from the fructo-oligosaccharides (FOS), and raffinose and stachyose from the raffinose family oligosaccharides (RFO). Extraction parameters including solvent concentration (35-85% v/v), extraction temperature (25-50°C) and sonication time (5-15min) were examined using response surface methodology (RSM). Ethanol concentration of 63% v/v, temperature of 40°C and extraction time of 10min gave maximal concentration of the extracted oligosaccharides. The experimental values under optimal conditions were consistent with the predicted values. UAE increased the concentration of extracted oligosaccharides in all fruits and vegetables from 2 to 4-fold compared to conventional extraction. The highest increase of total oligosaccharides extracted by UAE was detected in Jerusalem artichoke, 7.17±0.348g/100gFW, compared to 1.62±0.094g/100gFW with conventional method.

  3. Application of ultrasound for enhanced extraction of prebiotic oligosaccharides from selected fruits and vegetables.

    Science.gov (United States)

    Jovanovic-Malinovska, Ruzica; Kuzmanova, Slobodanka; Winkelhausen, Eleonora

    2015-01-01

    Ultrasound assisted extraction (UAE) was used to extract oligosaccharides from selected fruits (blueberry, nectarine, raspberry, watermelon) and vegetables (garlic, Jerusalem artichoke, leek, scallion, spring garlic and white onion). The individual fractions of the oligosaccharides were analyzed: 1-kestose (GF2), nystose (GF3) and 1F-β-fructofuranosylnystose (GF4) from the fructo-oligosaccharides (FOS), and raffinose and stachyose from the raffinose family oligosaccharides (RFO). Extraction parameters including solvent concentration (35-85% v/v), extraction temperature (25-50°C) and sonication time (5-15min) were examined using response surface methodology (RSM). Ethanol concentration of 63% v/v, temperature of 40°C and extraction time of 10min gave maximal concentration of the extracted oligosaccharides. The experimental values under optimal conditions were consistent with the predicted values. UAE increased the concentration of extracted oligosaccharides in all fruits and vegetables from 2 to 4-fold compared to conventional extraction. The highest increase of total oligosaccharides extracted by UAE was detected in Jerusalem artichoke, 7.17±0.348g/100gFW, compared to 1.62±0.094g/100gFW with conventional method. PMID:25116595

  4. Characterization of oligosaccharides from an antigenic mannan of Saccharomyces cerevisiae.

    Science.gov (United States)

    Young, M; Davies, M J; Bailey, D; Gradwell, M J; Smestad-Paulsen, B; Wold, J K; Barnes, R M; Hounsell, E F

    1998-08-01

    Mannans of the yeast Saccharomyces cerevisiae have been implicated as containing the allergens to which bakers and brewers are sensitive and also the antigen recognized by patients with Crohn's disease. A fraction of S. cerevisiae mannan, Sc500, having high affinity for antibodies in Crohn's patients has been characterized by NMR spectroscopy followed by fragmentation using alkaline elimination, partial acid hydrolysis and acetolysis. The released oligosaccharides were separated by gel filtration on a Biogel P4 column and analyzed by fluorescence labeling, HPLC and methylation analysis. The relationship between structure and antigen activity was measured by competitive ELISA. The antigenic activity of the original high molecular weight mannan could be ascribed to terminal Manalpha1-->3Manalpha1-->2 sequences which are rarely found in human glycoproteins but were over-represented in Sc500 compared to other yeast mannans.

  5. Recent insight into oligosaccharide uptake and metabolism in probiotic bacteria

    DEFF Research Database (Denmark)

    Abou Hachem, Maher; Andersen, Joakim Mark; Barrangou, Rodolphe;

    2013-01-01

    In recent years, a plethora of studies have demonstrated the paramount physiological importance of the gut microbiota on various aspects of human health and development. Particular focus has been set on probiotic members of this community, the best studied of which are assigned into the Lactobaci......, glycan metabolism is an important attribute of probiotic action and a factor influencing the composition of the gut microbiota. In the quest to understand the molecular mechanism of this selectivity for certain glycans, we have explored the routes of uptake and utilization of a variety...... of oligosaccharides differing in size, composition, and glycosidic linkages. A combination of "omics" technologies bioinformatics, enzymology and protein characterization proved fruitful in elucidating the protein transport and catabolic machinery conferring the utilization of glucosides, galactosides, and xylosides...

  6. Iron(Ⅲ) Trifluoroacetate:Chemoselective and Recyclable Lewis Acid Catalyst for Diacetylation of Aldehydes,Thioacetalization and Transthioacetalization of Carbonyl Compounds and Aerobic Coupling of Thiols

    Institute of Scientific and Technical Information of China (English)

    ADIBI Ha-di; SAMIMI Heshmat Allah; IRANPOOR Nasser

    2008-01-01

    Iron(Ⅲ)trifluoroacetate [Fe(CF3CO2)3] was found to be a recyclable,highly efficient and chemoselective Lewis acid catalyst for protection of a variety of carbonyl compounds as thioacetals under nearly neutral conditions.With the use of this catalyst,1,3-dithiolanes and 1,3-dithianes were obtained in high yields from various aldehydes.Un-der the same conditions ketones were similarly but more slowly thioketalized.This difference in reactivity between aldehydes and ketones was successfully utilized for the selective thioacetalization of aldehydes in the presence of ketones and also for the chemoselective conversion of β-diketone into the corresponding dithioacetal.Transthio-acetalization of O,O-acetals and O,O-ketals into cyclic thioacetals was also achieved by using this catalyst.Addi-tionally,iron(Ⅲ)trifluoroacetate has been found to be efficient catalyst for the addition of acetic anhydride to both aromatic and aliphatic aldehydes to afford 1,1-diacetates(gem diacetates).Aerobic dimerization of thiols was achieved by this reagent mediated by sodium iodide and air atmosphere.

  7. Effects of Wheat Bran Extract Containing Arabinoxylan Oligosaccharides on Gastrointestinal Parameters in Healthy Preadolescent Children

    NARCIS (Netherlands)

    Francois, Isabelle E. J. A.; Lescroart, Olivier; Veraverbeke, Wim S.; Marzorati, Massimo; Possemiers, Sam; Hamer, Henrike; Windey, Karen; Welling, Gjalt W.; Delcour, Jan A.; Courtin, Christophe M.; Verbeke, Kristin; Broekaert, Willem F.

    2014-01-01

    Objectives: We assessed whether wheat bran extract (WBE) containing arabinoxylan-oligosaccharides (AXOS) elicited a prebiotic effect and modulated gastrointestinal (GI) parameters in healthy preadolescent children upon consumption in a beverage. Methods: This double-blind randomized placebo-controll

  8. Chemically synthesized 58-mer LysM domain binds lipochitin oligosaccharide

    DEFF Research Database (Denmark)

    Sørensen, Kasper Kildegaard; Simonsen, Jens Bæk; Maolanon, Nicolai Nareth;

    2014-01-01

    Recognition of carbohydrates by proteins is a ubiquitous biochemical process. In legume-rhizobium symbiosis, lipochitin oligosaccharides, also referred to as nodulation (nod) factors, function as primary rhizobial signal molecules to trigger root nodule development. Perception of these signal mol...

  9. Immunomodulatory effects of dietary non-digestible oligosaccharides in T cell-mediated autoimmune arthritis

    NARCIS (Netherlands)

    Rogier, R.; Ederveen, T.; Hartog, A.; Walgreen, B.; Van Den Bersselaar, L.; Helsen, M.; Vos, P.; Garssen, J.; Willemsen, L.; Van Den Berg, W.; Koenders, M.; Abdollahi-Roodsaz, S.

    2015-01-01

    Background: Accumulating evidence indicates the relevance of intestinal microbiota in shaping the immune response and supports its contribution to the development of autoimmune diseases. Prebiotic non-digestible oligosaccharides are known to selectively support growth of commensal Bifidobacteria and

  10. OLIGOSACCHARIDE LEVELS IN IMMATURE AND NATURE SEEDS FROM SEVERAL VARIETIES OF PIGEON PEAS (Cajanus cajan)

    OpenAIRE

    Jairo Osvaldo CAZETTA; Hugo Candido SILVA; Gilberto Leite BRAGA; Roberto de CARVALHO

    2009-01-01

    ABSTRACT: Oligosaccharide level were evaluated in immature and nature seeds from different varieties of pigeon peas (Cajanus cajan) and compared to those of common beans (Phaseolus vulgaris) and peas (Pisum sativum): The effect of seed processing by soaking and cooking was also determined. Immature pigeon peas seeds presented low oligosaccharide levels when compared to mature pigeon pea seeds or to pea seeds, thus representing a good alternative for human consumption....

  11. Structural basis for arabinoxylo‐oligosaccharide capture by the probiotic Bifidobacterium animalis subsp. lactis Bl‐04

    DEFF Research Database (Denmark)

    Hansen, Morten Ejby; Fredslund, Folmer; Vujicic‐Zagar, Andreja;

    2013-01-01

    Glycan utilization plays a key role in modulating the composition of the gut microbiota, but molecular insight into oligosaccharide uptake by this microbial community is lacking. Arabinoxylo‐oligosaccharides (AXOS) are abundant in the diet, and are selectively fermented by probiotic bifidobacteria...... analyses show that BlAXBP is highly conserved within Bifidobacterium, but is lacking in other gut microbiota members. These data indicate niche adaptation within Bifidobacterium and highlight the metabolic syntrophy (cross‐feeding) among the gut microbiota....

  12. Structural basis for arabinoxylo-oligosaccharide capture by the probiotic Bifidobacterium animalis subsp lactis Bl-04

    OpenAIRE

    Ejby, Morten; Fredslund, Folmer; Vujicic-Zagar, Andreja; Svensson, Birte; Slotboom, Dirk Jan; Abou Hachem, Maher

    2013-01-01

    Glycan utilization plays a key role in modulating the composition of the gut microbiota, but molecular insight into oligosaccharide uptake by this microbial community is lacking. Arabinoxylo-oligosaccharides (AXOS) are abundant in the diet, and are selectively fermented by probiotic bifidobacteria in the colon. Here we show how selectivity for AXOS uptake is established by the probiotic strain Bifidobacterium animalis subsp. lactisBl-04. The binding protein BlAXBP, which is associated with an...

  13. Manufacture of gluco-oligosaccharide prebiotic by Gluconobacter oxydans NCIMB 4943

    Directory of Open Access Journals (Sweden)

    Santad Wichienchot

    2010-01-01

    Full Text Available This study investigated the optimal environmental factors for gluco-oligosaccharide production by Gluconobacter oxydans NCIMB 4943 from a range of commercial maltodextrins, and the influence of reaction parameters on the molecular weight distribution and chemical structure of the gluco-oligosaccharide products. G. oxydans gave significantly (p<0.01 higher gluco-oligosaccharide yield in maltodextrin complex medium (30.4% than using cell suspensions (19.6%. Cell concentration had a significant (p<0.05 effect on gluco-oligosaccharide yields at 24 h. The optimal pH was found to be 4.5 for the cell suspension method. Temperature had a significant (p<0.05 effect and the optimal temperature was found to be30°C. Maximum yield (30.0% was obtained with high dextrose equivalent (DE maltodextrin in maltodextrin complexmedium. Low DE substrates gave the lowest gluco-oligosaccharide yields. Substrate concentration affected gluco-oligosaccharideformation significantly (p<0.05. Low molecular weight (approximately 1 kDa maltodextrin was converted to higher molecular weight gluco-oligosaccharide (7.8-65.6 kDa with ratios of -1,6-, -1,4- and -1,4,6-D-glucosidic linkages in the ranges of 1.37-3.99, 1.48-4.30 and 0.29-0.73 respectively, depending on the manufacturing conditions. Glucooligosaccharides contained at least 88 glucose residues.

  14. Lactodifucotetraose, a human milk oligosaccharide, attenuates platelet function and inflammatory cytokine release.

    Science.gov (United States)

    Newburg, David S; Tanritanir, Ayse C; Chakrabarti, Subrata

    2016-07-01

    Human milk strongly quenches inflammatory processes in vitro, and breastfed infants have lower incidence of inflammatory diseases than those fed artificially. Platelets from neonates, in contrast to those from adults, are less responsive to platelet agonists such as collagen, thrombin, ADP, and epinephrine. Breastfed infants absorb oligosaccharides intact from the human milk in their gut to the circulation. This study was to determine whether these oligosaccharides can attenuate platelet function and platelet secretion of pro-inflammatory proteins, and to identify the active component. The natural mixture of oligosaccharides from human milk and pure individual human milk oligosaccharides were tested for their ability to modulate responses of platelets isolated from human blood following exposure to thrombin, ADP, and collagen. Human milk and the natural mixture of human milk oligosaccharides inhibited platelet release of inflammatory proteins. Of the purified human milk oligosaccharides tested, only lactodifucotetraose (LDFT) significantly inhibited thrombin induced release of the pro-inflammatory proteins RANTES and sCD40L. LDFT also inhibited platelet adhesion to a collagen-coated surface, as well as platelet aggregation induced by ADP or collagen. These data indicate that LDFT may help modulate hemostasis by suppressing platelet-induced inflammatory processes in breastfed infants. This activity suggests further study of LDFT for its potential as a therapeutic agent in infants and adults.

  15. Separation of xylo-oligosaccharides from enzymatic hydrolytes using membrane reactor

    Institute of Scientific and Technical Information of China (English)

    杨富国; 方正; 徐勇; 姚春才; 余世袁; 朱琼霞

    2003-01-01

    The time course of xylo-oligosaccharides concentration and xylo-oligosaccharides yield in the separation of xylo-oligosaccharides from enzymatic hydrolytes was studied using a membrane reactor with constant permeate flux of 4 L @ m-2 @ h-1. The results show that xylanases retain 90% of its activity in the reactor. The concentration of xylo-oligosaccharides achieves the maximum, about 5.48 g/L in 30 min. The difference of xylo-oligosaccharides in the retentate and permeate stream is low, <0.62 g/L, therefore it can permeate through membrane. Under the operating conditions that xylan concentration is 30.0 g/L, pH 5.0, operating pressure 16 kPa, temperature 48 ℃,feed velocity 400 mL/min, reaction volume 400 mL, enzyme dosage 10%(volume fraction), dilution rate 1 h -1, and enzymatic hydrolysis time 195 min, the yield of xylo-oligosaccharides reaches 31.69 %.

  16. Lactodifucotetraose, a human milk oligosaccharide, attenuates platelet function and inflammatory cytokine release.

    Science.gov (United States)

    Newburg, David S; Tanritanir, Ayse C; Chakrabarti, Subrata

    2016-07-01

    Human milk strongly quenches inflammatory processes in vitro, and breastfed infants have lower incidence of inflammatory diseases than those fed artificially. Platelets from neonates, in contrast to those from adults, are less responsive to platelet agonists such as collagen, thrombin, ADP, and epinephrine. Breastfed infants absorb oligosaccharides intact from the human milk in their gut to the circulation. This study was to determine whether these oligosaccharides can attenuate platelet function and platelet secretion of pro-inflammatory proteins, and to identify the active component. The natural mixture of oligosaccharides from human milk and pure individual human milk oligosaccharides were tested for their ability to modulate responses of platelets isolated from human blood following exposure to thrombin, ADP, and collagen. Human milk and the natural mixture of human milk oligosaccharides inhibited platelet release of inflammatory proteins. Of the purified human milk oligosaccharides tested, only lactodifucotetraose (LDFT) significantly inhibited thrombin induced release of the pro-inflammatory proteins RANTES and sCD40L. LDFT also inhibited platelet adhesion to a collagen-coated surface, as well as platelet aggregation induced by ADP or collagen. These data indicate that LDFT may help modulate hemostasis by suppressing platelet-induced inflammatory processes in breastfed infants. This activity suggests further study of LDFT for its potential as a therapeutic agent in infants and adults. PMID:26743063

  17. Oligosaccharides in several Philippine indigenous food legumes: determination, localization and removal.

    Science.gov (United States)

    Revilleza, M J; Mendoza, E M; Raymundo, L C

    1990-01-01

    The oligosaccharide profile of raw mature seeds of seven different legumes indigenous to the Philippines was measured in 70% ethanol extracts of the seeds by thin layer chromatography using HPTLC plates and quantified by a densitometer. Based on the results, the legumes could be ranked according to decreasing oligosaccharide content or flatulence potential as follows: Sam-samping (Clitoria ternatea) greater than hyacinth bean (Dolichos lablab) greater than sabawel (Mucuna pruriens) greater than lima bean (Phaseolus lunatus) greater than swordbean (Canavalia gladiata) greater than rice bean (Vigna umbellata) greater than jack bean (Canavalia ensiformis). Sam-samping had 4.79% total oligosaccharides and hyacinth bean or batao, 3.66%. A jack bean accession had 1.79% oligosaccharides. Simple processing methods were tested to detoxify the oligosaccharides. Soaking the batao seeds had no effect while boiling even resulted in a net 23-31% increase in the levels of raffinose, stachyose and verbascose. On the other hand, two min of dry roasting resulted in complete removal of oligosaccharides whereas germination resulted in about 30-40% decrease after 1 and 2 days, respectively. PMID:2345736

  18. Structural characterization of novel L-galactose-containing oligosaccharide subunits of jojoba seed xyloglucans.

    Science.gov (United States)

    Hantus, S; Pauly, M; Darvill, A G; Albersheim, P; York, W S

    1997-10-28

    Jojoba seed xyloglucan was shown to be a convenient source of biologically active xyloglucan oligosaccharides that contain both L- and D-galactosyl residues [E. Zablackis et al., Science, 272 (1996) 1808-1810]. Oligosaccharides were isolated by liquid chromatography of the mixture of oligosaccharides generated by treating jojoba seed xyloglucan with a beta-(1-->4)-endoglucanase. The purified oligosaccharides were reduced with NaBH4, converting them to oligoglycosyl alditol derivatives that were structurally characterized by a combination of mass spectrometry and 2-dimensional NMR spectroscopy. This analysis established that jojoba xyloglucan oligosaccharides contain the novel side-chain [alpha-L-Gal p-(1-->2)-beta-D-Galp-(1-->2)-alpha-D-Xyl p-(1-->6)-], which is structurally homologous to the fucose-containing side-chain [alpha-L-Fucp-(1-->2)-beta-D-Galp-(1-->2)-alpha-D-Xyl p-(1-->6)-] found in other biologically active xyloglucan oligosaccharides.

  19. Effect of Different Oligosaccharides on Immunity, and Cecal Microflora in Broilers

    Institute of Scientific and Technical Information of China (English)

    GAO Ying; SHAN An-shan

    2004-01-01

    One hundred and forty-four Avin broilers (1 d old) were randomly divided into six treatments, with three replicates of eight birds each to investigate the effect of different oligosaccharides on index of immune organ, cecal weight and microflora in broilers. The control group (Group Ⅰ) was fed with corn-soybean meal as basal diet, and the trial groups (group Ⅱ, Ⅲ, Ⅳ, Ⅴ and Ⅵ ) were fed with basal diet plus 0.1% manoligosaccharides (MOS), 0.3% soybean-oligosaccharides (SBOS), 0.3% fructooligosaccharides (FOS), 0.3% α -glucooligosaccharides(α -GOS) and 0.03% chlortetracycline (CTC), respectively. The results showed that oligosaccharides supplementation significantly (P<0.05) increased bifidobacteria concentration ofyoung broilers and did not affect on bifidobacteria or escherichia coli concentration of the birds ( P >0.05). Cecal weights of 21 d old broilers fed with FOS and α -GOS were significantly (P <0.05) increased, higher than those with MOS and SBOS, but addition of oligosaccharides had no effect on the birds. The effect of oligosaccharides on the cecal length was the same as on the cecal weights. Oligosaccharides supplement did not affect on indexes of immune organs.

  20. Characterization of the glucansucrase GTF180 W1065 mutant enzymes producing polysaccharides and oligosaccharides with altered linkage composition.

    Science.gov (United States)

    Meng, Xiangfeng; Pijning, Tjaard; Tietema, Martin; Dobruchowska, Justyna M; Yin, Huifang; Gerwig, Gerrit J; Kralj, Slavko; Dijkhuizen, Lubbert

    2017-02-15

    Exopolysaccharides produced by lactic acid bacteria are extensively used for food applications. Glucansucrase enzymes of lactic acid bacteria use sucrose to catalyze the synthesis of α-glucans with different linkage compositions, size and physico-chemical properties. Crystallographic studies of GTF180-ΔN show that at the acceptor binding sites +1 and +2, residue W1065 provides stacking interactions to the glucosyl moiety. However, the detailed functional roles of W1065 have not been elucidated. We performed random mutagenesis targeting residue W1065 of GTF180-ΔN, resulting in the generation of 10 mutant enzymes that were characterized regarding activity and product specificity. Characterization of mutant enzymes showed that residue W1065 is critical for the activity of GTF180-ΔN. Using sucrose, and sucrose (donor) plus maltose (acceptor) as substrates, the mutant enzymes synthesized polysaccharides and oligosaccharides with changed linkage composition. The stacking interaction of an aromatic residue at position 1065 is essential for polysaccharide synthesis. PMID:27664611

  1. Mass spectrometric detection of multiple extended series of neutral highly fucosylated N-acetyllactosamine oligosaccharides in human milk

    Science.gov (United States)

    Pfenninger, Anja; Chan, Shiu-Yung; Karas, Michael; Finke, Berndt; Stahl, Bernd; Costello, Catherine E.

    2008-12-01

    Complex mixtures of high-molecular weight fractions of pooled neutral human milk oligosaccharides (obtained via gel permeation chromatography) have been investigated. The subfractions were each permethylated and analyzed by high-resolution mass spectrometry, using matrix-assisted laser desorption/ionization (MALDI)-Fourier transform ion cyclotron resonance (FTICR) mass spectrometry, in order to investigate their oligosaccharide compositions. The obtained spectra reveal that human milk contains more complex neutral oligosaccharides than have been described previously; the data show that these oligosaccharides can be highly fucosylated, and that their poly-N-acetyllactosamine cores are substituted with up to 10 fucose residues on an oligosaccharide that has 7-N-acetyllactosamine units. This is the first report of the existence in human milk of this large range of highly fucosylated oligosaccharides which possess novel, potentially immunologically active structures.

  2. Methodologies for screening of bacteria-carbohydrate interactions: anti-adhesive milk oligosaccharides as a case study.

    Science.gov (United States)

    Lane, Jonathan A; Mariño, Karina; Rudd, Pauline M; Carrington, Stephen D; Slattery, Helen; Hickey, Rita M

    2012-07-01

    Many studies have demonstrated the capacity of glycan-based compounds to disrupt microbial binding to mucosal epithelia. Therefore, oligosaccharides have potential application in the prevention of certain bacterial diseases. However, current screening methods for the identification of anti-adhesive oligosaccharides have limitations: they are time-consuming and require large amounts of oligosaccharides. There is a need to develop analytical techniques which can quickly screen for, and structurally define, anti-adhesive oligosaccharides prior to using human cell line models of infection. Considering this, we have developed a rapid method for screening complex oligosaccharide mixtures for potential anti-adhesive activity against bacteria. Our approach involves the use of whole bacterial cells to "deplete" free oligosaccharides from solution. As a case study, the free oligosaccharides from the colostrum of Holstein Friesian cows were screened for interactions with whole Escherichia coli cells. Reductions in oligosaccharide concentrations were determined by High pH Anion Exchange Chromatography and Hydrophilic Interaction Liquid Chromatography (HILIC-HPLC). Oligosaccharide structures were confirmed by a combination of HILIC-HPLC, exoglycosidase digestion and off-line negative ion mode MS/MS. The depletion assay confirmed selective bacterial interaction with certain bovine oligosaccharides which in previous studies, by other methodologies, had been shown to interact with E. coli. In particular, the bacterial cells depleted the following oligosaccharides in a population dependent manner: 3'-sialyllactose, disialyllactose, and 6'-sialyllactosamine. The assay methodology was further validated by studies in which we demonstrated the inhibitory activity of 3'-sialyllactose, and a mixture of bovine colostrum oligosaccharides, on E. coli adhesion to differentiated HT-29 cells. PMID:22507447

  3. Fractionation, solid-phase immobilization and chemical degradation of long pectin oligogalacturonides. Initial steps towards sequencin of oligosaccharides

    DEFF Research Database (Denmark)

    Guillaumie, Fanny; Justesen, Sune F. L.; Mutenda, Kudzai E.;

    2006-01-01

    were produced in excellent purity (>95%). Elution of OGAs followed by direct analysis of the peak fractions by MALDI-TOF MS. Purified OGAs (DP 5-7) were chemoselectively immobilized onto aminooxy-terminated polyethylene glycol polyacrylamide (PEGA) supports. Solid-phase anchoring took place...

  4. Fractionation, solid-phase immobilization and chemical degradation of long pectin oligogalacturonides. Initial steps towards sequencing of oligosaccharides

    DEFF Research Database (Denmark)

    Guillaumie, Fanny; Justesen, Sune Frederik Lamdahl; Mutenda, K.E.;

    2006-01-01

    were produced in excellent purity (> 95%). Elution of OGAs followed by direct analysis of the peak fractions by MALDI-TOF MS. Purified OGAs (DP 5-7) were chemoselectively immobilized onto aminooxy-terminated polyethylene glycol polyacrylamide (PEGA) supports. Solid-phase anchoring took place...

  5. Biomimetic oligosaccharide and peptide surfactant polymers designed for cardiovascular biomaterials

    Science.gov (United States)

    Ruegsegger, Mark Andrew

    A common problem associated with cardiovascular devices is surface induced thrombosis initiated by the rapid, non-specific adsorption of plasma proteins onto the biomaterial surface. Control of the initial protein adsorption is crucial to achieve the desired longevity of the implanted biomaterial. The cell membrane glycocalyx acts as a non-thrombogenic interface through passive (dense oligosaccharide structures) and active (ligand/receptor interactions) mechanisms. This thesis is designed to investigate biomimicry of the cell glycocalyx to minimize non-specific protein adsorption and promote specific ligand/receptor interactions. Biomimetic macromolecules were designed through the molecular-scale engineering of polymer surfactants, utilizing a poly(vinyl amine) (PVAm) backbone to which hydrophilic (dextran, maltose, peptide) and hydrophobic alkyl (hexanoyl or hexanal) chains are simultaneously attached. The structure was controlled through the molar feed ratio of hydrophobic-to-hydrophilic groups, which also provided control of the solution and surface-active properties. To mimic passive properties, a series of oligomaltose surfactants were synthesized with increasing saccharide length (n = 2, 7, 15 where n is number of glucose units) to investigate the effect of coating height on protein adsorption. The surfactants were characterized by infra red (IR) and nuclear magnetic resonance (NMR) spectroscopies for structural properties and atomic force microscopy (AFM) and contact angle goniometry for surface activity. Protein adsorption under dynamic flow (5 dyn/cm2) was reduced by 85%--95% over the bare hydrophobic substrate; platelet adhesion dropped by ˜80% compared to glass. Peptide ligands were incorporated into the oligosaccharide surfactant to promote functional activity of the passive coating. The surfactants were synthesized to contain 0%, 25%, 50%, 75%, and 100% peptide ligand density and were stable on hydrophobic surfaces. The peptide surface density was

  6. Occurrence of heterogeneity of N-linked oligosaccharides attached to sycamore (Acer pseudoplatanus L.) laccase after excretion.

    Science.gov (United States)

    Tezuka, K; Hayashi, M; Ishihara, H; Onozaki, K; Nishimura, M; Takahashi, N

    1993-03-01

    The N-linked oligosaccharide moieties of sycamore (Acer pseudoplatanus L.) laccase are known to be highly heterogeneous. We confirmed that this oligosaccharide heterogeneity was caused not only during the oligosaccharide biosynthesis in Golgi apparatus, but also after the excretion of laccase protein into a culture medium. The culture medium for the sycamore cells (Acer pseudoplatanus L.) contained beta-galactosidase, alpha-L-fucosidase, beta-N-acetylglucosaminidase, alpha-mannosidase and beta-xylosidase activities. We showed that the largest sugar chain in laccase, oligosaccharide F, [formula: see text] was degraded to [formula: see text] by a crude exoglycosidase mixture in the culture medium.

  7. A bio-inspired total synthesis of tetrahydrofuran lignans.

    Science.gov (United States)

    Albertson, Anna K F; Lumb, Jean-Philip

    2015-02-01

    Lignan natural products comprise a broad spectrum of biologically active secondary metabolites. Their structural diversity belies a common biosynthesis, which involves regio- and chemoselective oxidative coupling of propenyl phenols. Attempts to replicate this oxidative coupling have revealed significant challenges for controlling selectivity, and these challenges have thus far prevented the development of a unified biomimetic route to compounds of the lignan family. A practical solution is presented that hinges on oxidative ring opening of a diarylcyclobutane to intercept a putative biosynthetic intermediate. The effectiveness of this approach is demonstrated by the first total synthesis of tanegool in 4 steps starting from ferulic acid, as well as a concise synthesis of the prototypical furanolignan pinoresinol.

  8. Specific sizes of hyaluronan oligosaccharides stimulate fibroblast migration and excisional wound repair.

    Directory of Open Access Journals (Sweden)

    Cornelia Tolg

    Full Text Available The extracellular matrix polysaccharide hyaluronan (HA plays a key role in both fibrotic and regenerative tissue repair. Accumulation of high molecular weight HA is typical of regenerative repair, which is associated with minimal inflammation and fibrosis, while fragmentation of HA is typical of postnatal wounds, which heal in the presence of inflammation and transient fibrosis. It is generally considered that HA oligosaccharides and fragments of a wide size range support these processes of adult, fibrotic wound repair yet the consequences of sized HA fragments/oligosaccharides to each repair stage is not well characterized. Here, we compared the effects of native HA, HA oligosaccharide mixtures and individual sizes (4-10 mer oligosaccharides, 5 and, 40 kDa of HA oligosaccharides and fragments, on fibroblast migration in scratch wound assays and on excisional skin wound repair in vivo. We confirm that 4-10 mer mixtures significantly stimulated scratch wound repair and further report that only the 6 and 8 mer oligosaccharides in this mixture are responsible for this effect. The HA 6 mer promoted wound closure, accumulation of wound M1 and M2 macrophages and the M2 cytokine TGFβ1, but did not increase myofibroblast differentiation. The effect of 6 mer HA on wound closure required both RHAMM and CD44 expression. In contrast, The 40 kDa HA fragment inhibited wound closure, increased the number of wound macrophages but had no effect on TGFβ1 accumulation or subsequent fibrosis. These results show that specific sizes of HA polymer have unique effects on postnatal wound repair. The ability of 6 mer HA to promote wound closure and inflammation resolution without increased myofibroblast differentiation suggests that this HA oligosaccharide could be useful for treatment of delayed or inefficient wound repair where minimal fibrosis is advantageous.

  9. OMICS-rooted studies of milk proteins, oligosaccharides and lipids.

    Science.gov (United States)

    Casado, Begoña; Affolter, Michael; Kussmann, Martin

    2009-12-01

    Milk has co-evolved with mammals and mankind to nourish their offspring and is a biological fluid of unique complexity and richness. It contains all necessary nutrients for the growth and development of the newborn. Structure and function of biomolecules in milk such as the macronutrients (glyco-) proteins, lipids, and oligosaccharides are central topics in nutritional research. Omics disciplines such as proteomics, glycomics, glycoproteomics, and lipidomics enable comprehensive analysis of these biomolecule components in food science and industry. Mass spectrometry has largely expanded our knowledge on these milk bioactives as it enables identification, quantification and characterization of milk proteins, carbohydrates, and lipids. In this article, we describe the biological importance of milk macronutrients and review the application of proteomics, glycomics, glycoproteomics, and lipidomics to the analysis of milk. Proteomics is a central platform among the Omics tools that have more recently been adapted and applied to nutrition and health research in order to deliver biomarkers for health and comfort as well as to discover beneficial food bioactives.

  10. Oligosaccharides and monomeric carbohydrates production from olive tree pruning biomass.

    Science.gov (United States)

    Mateo, Soledad; Puentes, Juan G; Sánchez, Sebastián; Moya, Alberto J

    2013-04-01

    Using the severity factor, it has been possible to study cellulose and hemicellulose fractional conversion, sugar yields change and oligosaccharides variation through olive tree pruning biomass pretreatments with acid or liquid hot water under pressure. The temperatures tested were in the range 180-230°C, operation time varying between 0 and 30min and acid concentration used did not exceed 0.05M. Complete hemicellulose solubilization in autohydrolysis was achieved using severity factors (logR0) close to 3.9 (most sugars are like oligomers), while if sulfuric acid 0.025M is employed, this parameter could be smaller (≥3.4). With these treatments, we have obtained cellulose conversions between 30 and 42% from liquid hot water experiments, 40-51% with sulfuric acid 0.025M and 42-57% when the acid concentration was 0.05M. The best results in terms of maximum yield in total sugars, d-glucose and d-xylose, with a low amount of acetic acid and hydroxymethylfurfural, was obtained at 200°C, 0min (what means that there is no time of temperature maintenance, only heating and cooling) and H2SO4 0.025M. PMID:23499077

  11. Recent developments in manufacturing oligosaccharides with prebiotic functions.

    Science.gov (United States)

    Kovács, Zoltán; Benjamins, Eric; Grau, Konrad; Ur Rehman, Amad; Ebrahimi, Mehrdad; Czermak, Peter

    2014-01-01

    The market for prebiotics is steadily growing. To satisfy this increasing worldwide demand, the introduction of effective bioprocessing methods and implementation strategies is required. In this chapter, we review recent developments in the manufacture of galactooligosaccharides (GOS) and fructooligosaccharides (FOS). These well-established oligosaccharides (OS) provide several health benefits and have excellent technological properties that make their use as food ingredients especially attractive. The biosyntheses of lactose-based GOS and sucrose-based FOS show similarities in terms of reaction mechanisms and product formation. Both GOS and FOS can be synthesized using whole cells or (partially) purified enzymes in immobilized or free forms. The biocatalysis results in a final product that consists of OS, unreacted disaccharides, and monosaccharides. This incomplete conversion poses a challenge to manufacturers because an enrichment of OS in this mixture adds value to the product. For removing digestible carbohydrates from OS, a variety of bioengineering techniques have been investigated, including downstream separation technologies, additional bioconversion steps applying enzymes, and selective fermentation strategies. This chapter summarizes the state-of-the-art manufacturing strategies and recent advances in bioprocessing technologies that can lead to new possibilities for manufacturing and purifying sucrose-based FOS and lactose-based GOS.

  12. β-mannanase and mannan oligosaccharides in broiler chicken feed

    Directory of Open Access Journals (Sweden)

    Victor Ramos Sales Mendes de Barros

    2015-01-01

    Full Text Available The study aimed to evaluate the use of β-mannanase and mannan oligosaccharides (MOS to replace growth promoters in broiler diets. Four hundred male Cobb broiler chicks were used, with initial weight of 45±1g, distributed in a completely randomized design with five treatments and eight repetitions of ten birds. The treatments were: basal feed; basal feed without growth promoter; basal feed without growth promoter + β-mannanase; basal feed without growth promoter + MOS; and basal feed without growth promoter + β-mannanase + MOS. The feed intake of the birds increased in response to dietary treatments compared to basal diet during the period 1-21 days of age. A higher weight gain and improved feed conversion was found at 42 days of age among birds that had received the basal diet without growth promoter + MOS. The absolute weight at slaughter, relative carcass and prime cuts except breast weights improved in response to dietary treatments compared to the basal diet at 42 days of age. No difference was observed in relative weight of the liver, while significant differences were found in the weight of heart, gizzard, and abdominal fat. It was concluded that β-mannanase and MOS can replace the growth promoters in broiler diets without compromising production and economic performance. However, the association of these products into the feed may cause negative interaction that reduces the broiler chickens' performance

  13. Galacto-oligosaccharides attenuate renal injury with microbiota modification.

    Science.gov (United States)

    Furuse, Satoshi U; Ohse, Takamoto; Jo-Watanabe, Airi; Shigehisa, Akira; Kawakami, Koji; Matsuki, Takahiro; Chonan, Osamu; Nangaku, Masaomi

    2014-07-01

    Tubulointerstitial injury is central to the progression of end-stage renal disease. Recent studies have revealed that one of the most investigated uremic toxins, indoxyl sulfate (IS), caused tubulointerstitial injury through oxidative stress and endoplasmic reticulum (ER) stress. Because indole, the precursor of IS, is synthesized from dietary tryptophan by the gut microbiota, we hypothesized that the intervention targeting the gut microbiota in kidney disease with galacto-oligosaccharides (GOS) would attenuate renal injury. After 2 weeks of GOS administration for 5/6 nephrectomized (Nx) or sham-operated (Sham) rats, cecal indole and serum IS were measured, renal injury was evaluated, and the effects of GOS on the gut microbiota were examined using pyrosequencing methods. Cecal indole and serum IS were significantly decreased and renal injury was improved with decreased infiltrating macrophages in GOS-treated Nx rats. The expression levels of ER stress markers and apoptosis were significantly increased in the Nx rats and decreased with GOS. The microbiota analysis indicated that GOS significantly increased three bacterial families and decreased five families in the Nx rats. In addition, the analysis also revealed that the bacterial family Clostridiaceae was significantly increased in the Nx rats compared with the Sham rats and decreased with GOS. Taken altogether, our data show that GOS decreased cecal indole and serum IS, attenuated renal injury, and modified the gut microbiota in the Nx rats, and that the gut microbiota were altered in kidney disease. GOS could be a novel therapeutic agent to protect against renal injury.

  14. Enzymatic production of pectic oligosaccharides from onion skins.

    Science.gov (United States)

    Babbar, Neha; Baldassarre, Stefania; Maesen, Miranda; Prandi, Barbara; Dejonghe, Winnie; Sforza, Stefano; Elst, Kathy

    2016-08-01

    Onion skins are evaluated as a new raw material for the enzymatic production of pectic oligosaccharides (POS) with a targeted degree of polymerization (DP). The process is based on a two-stage process consisting of a chelator-based crude pectin extraction followed by a controlled enzymatic hydrolysis. Treatment of the extracted crude onion skin's pectin with various enzymes (EPG-M2, Viscozyme and Pectinase) shows that EPG-M2 is the most appropriate enzyme for tailored POS production. The experiments reveal that the highest amount of DP2 and DP3 is obtained at a time scale of 75-90min with an EPG-M2 concentration of 26IU/mL. At these conditions the production amounts 2.5-3.0% (w/w) d.m for DP2 and 5.5-5.6% (w/w) d.m for DP3 respectively. In contrast, maximum DP4 production of 5.2-5.5% (w/w) d.m. is obtained with 5.2IU/mL at a time scale of 15-30min. Detailed LC-MS analysis reveals the presence of more methylated oligomers compared to acetylated forms in the digests. PMID:27112872

  15. Evaluation of commercial resins for fructo-oligosaccharide separation.

    Science.gov (United States)

    Nobre, C; Suvarov, P; De Weireld, G

    2014-01-25

    Fructo-oligosaccharides (FOS) produced by fermentative processes are obtained in mixtures containing significant amounts of salts and other non-prebiotic sugars. A demineralisation process using a mixture of a cationic and an anionic resin was proposed. The separation of FOS from a mixture of fructose, glucose and sucrose was evaluated. Experiments were conducted with several commercial cationic exchange resins in calcium, sodium and potassium forms packed in preparative columns (7cm×2.2cm length×diameter). Resins in potassium form obtained the higher retention factor values for sugars when compared to the other ionic forms. However, when compared to calcium and sodium ones, resins in potassium cationic forms were shown to be the less efficient separating sugar mixtures. The resin with best separation performance was the Diaion UBK535Ca. A recovery yield of 92% (w/w) of FOS with 90% (w/w) of purity was obtained from batch experiments conducted in a single column loaded with the Diaion UBK535Ca resin at 25°C. The temperature shown did not influence the separation performance significantly. By increasing the column length, the purity of FOS increased to 92% (w/w), however the recovery yield decreased to 88% (w/w). PMID:23806732

  16. Recent developments in manufacturing oligosaccharides with prebiotic functions.

    Science.gov (United States)

    Kovács, Zoltán; Benjamins, Eric; Grau, Konrad; Ur Rehman, Amad; Ebrahimi, Mehrdad; Czermak, Peter

    2014-01-01

    The market for prebiotics is steadily growing. To satisfy this increasing worldwide demand, the introduction of effective bioprocessing methods and implementation strategies is required. In this chapter, we review recent developments in the manufacture of galactooligosaccharides (GOS) and fructooligosaccharides (FOS). These well-established oligosaccharides (OS) provide several health benefits and have excellent technological properties that make their use as food ingredients especially attractive. The biosyntheses of lactose-based GOS and sucrose-based FOS show similarities in terms of reaction mechanisms and product formation. Both GOS and FOS can be synthesized using whole cells or (partially) purified enzymes in immobilized or free forms. The biocatalysis results in a final product that consists of OS, unreacted disaccharides, and monosaccharides. This incomplete conversion poses a challenge to manufacturers because an enrichment of OS in this mixture adds value to the product. For removing digestible carbohydrates from OS, a variety of bioengineering techniques have been investigated, including downstream separation technologies, additional bioconversion steps applying enzymes, and selective fermentation strategies. This chapter summarizes the state-of-the-art manufacturing strategies and recent advances in bioprocessing technologies that can lead to new possibilities for manufacturing and purifying sucrose-based FOS and lactose-based GOS. PMID:23942834

  17. α-D-Mannopyranosylmethyl-P-nitrophenyltriazene effects on the degradation and biosynthesis of N-linked oligosaccharide chains on α1-acid glycoprotein by liver cells

    International Nuclear Information System (INIS)

    The effects of α-D-mannopyranosylmethyl-p-nitrophenyltriazene (α-ManMNT) on the degradation and processing of oligosaccharide chains on α1-acid glycoprotein (AGP) were studied. Addition of the triazene to a perfused liver blocked the complete degradation of endocytosed N-acetyl [14C]glucosamine-labeled asialo-AGP and caused the accumulation of Man2GlcNAc1 fragments in the lysosome-enriched fraction of the liver homogenate. This compound also reduced the reincorporation of lysosomally-derived [14C]GlcNAc into newly secreted glycoproteins. Cultured hepatocytes treated with the inhibitor synthesized and secreted fully-glycosylated AGP. However, the N-linked oligosaccharide chains on AGP secreted by the α-ManMNT-treated hepatocytes remained sensitive to digestion with endoglycosidase H, were resistant to neuraminidase, and consisted of Man/sub 9-7/GlcNAc2 structures as analyzed by high resolution Bio-Gel P-4 chromatography. As measured by their resistance to cleavage by endoglycosidase H, the normal processing of all six carbohydrate chains on AGP to the complex form did not completely resume until nearly 24 h after triazene treatment. Since ManMNT is likely to irreversibly inactivate α-D-mannosidases, the return of AGP to secretory forms with complex chains after 24 h probably resulted from synthesis of new processing enzymes

  18. Enhancing Metal-Support Interactions by Molybdenum Carbide: An Efficient Strategy toward the Chemoselective Hydrogenation of α,β-Unsaturated Aldehydes.

    Science.gov (United States)

    He, Sina; Shao, Zheng-Jiang; Shu, Yijin; Shi, Zhangping; Cao, Xiao-Ming; Gao, Qingsheng; Hu, Peijun; Tang, Yi

    2016-04-11

    Metal-support interactions are desired to optimize the catalytic turnover on metals. Herein, the enhanced interactions by using a Mo2C nanowires support were utilized to modify the charge density of an Ir surface, accomplishing the selective hydrogenation of α,β-unsaturated aldehydes on negatively charged Ir(δ-) species. The combined experimental and theoretical investigations showed that the Ir(δ-) species derive from the higher work function of Ir (vs. Mo2C) and the consequently electron transfer. In crotonaldehyde hydrogenation, Ir/Mo2C delivered a crotyl alcohol selectivity as high as 80%, outperforming those of counterparts (Mo2C was highlighted by its higher selectivity as well as the better activity. Additionally, the efficacy for various substrates further verified our Ir/Mo2C system to be competitive for chemoselective hydrogenation.

  19. Production, properties and applications of oligosaccharidesProdução, propriedades e aplicações de oligossacarídeos

    Directory of Open Access Journals (Sweden)

    Roberto da Silva

    2011-07-01

    Full Text Available Oligosaccharides participate in the formation of dietary fiber and are mainly used as prebiotic agents. This review presents ways of obtaining these sugars, which can be produced by synthesis (chemical or enzymatic, or through depolymerization of polysaccharides (physical, chemical or enzymatic. Oligosaccharides have also been used commercially as an ingredient in cosmetics, pharmaceuticals, agricultural products and especially in the food industry because of their physical properties. The potential applications of oligosaccharides in several areas such as food, animal feed, pharmaceuticals and cosmetics have contributed to the increase in scientific research on these carbohydrates. The use of oligosaccharides as immuno-modulatory agents and biological response modifiers has been recently described, and their effects as anti-inflammatory and in reducing cholesterol. An overview of the various nutraceutical and biological functions of these carbohydrates in order to benefit human health is also reported.Os oligossacarídeos participam da constituição da fibra alimentar e são principalmente utilizados como prebióticos. Esta revisão apresenta as vias de obtenção destes açúcares, os quais podem ser produzidos por síntese (química ou enzimática ou da despolimerização de polissacarídeos (física, química ou enzimática, como descrito na presente revisão. Os oligossacarídeos vêm sendo utilizados comercialmente como ingredientes de cosméticos, medicamentos, produtos agrícolas e principalmente na indústria alimentícia. O potencial de aplicações dos oligossacarídeos nessas áreas nas mais diversas áreas tais como alimentos, rações animais, fármacos e cosméticos tem contribuído para o aumento das investigações científicas. O uso de oligossacarídeos como agentes imunomoduladores e modificadores de respostas biológicas foi recentemente descrito, assim como seus efeitos como compostos antiinflamatórios e hipocolesterol

  20. Screening,cloning,expression,characterization of β-galactosidase and enzymatic synthesis of galacto-oligosaccharides%β半乳糖苷酶的筛选、克隆表达、酶学性质及其酶法合成低聚半乳糖

    Institute of Scientific and Technical Information of China (English)

    王欣; 吴斌; 何冰芳

    2015-01-01

    采用人工底物邻硝基苯酚β D 半乳糖苷( oNPG)为筛选标记,从耐有机溶剂微生物菌库中,筛选出具有较高水解活性的β半乳糖苷酶产生菌,再以乳糖为底物考察菌株低聚半乳糖的合成性能,筛选得到1株产β半乳糖苷酶的Erwinia billingiae WX1。根据GenBank中相同属种的基因组序列推测β半乳糖苷酶基因,克隆得到β半乳糖苷酶基因gal,并在大肠杆菌中实现了来源于Erwinia billingiae菌β半乳糖苷酶的克隆表达。该基因的开放阅读框(ORF)为1428 bp,编码475个氨基酸,理论相对分子质量为5�2×104。镍柱法分离纯化得到电泳纯的β半乳糖苷酶GAL,其酶学性质研究表明最适催化温度55℃,最适pH 7�0;Mg2+、Mn2+对该酶起较强促进作用, EDTA对该酶抑制作用较强。利用β半乳糖苷酶GAL的转糖基作用,以乳糖为底物合成低聚半乳糖,初步优化的反应条件:底物乳糖质量浓度400 g/L,每克乳糖添加酶量1�0 U,在40℃反应16 h后,低聚半乳糖合成率达到34%(质量分数),显示了较好的开发前景。%Strains were screened from organic solvent tolerant bacteria, though the hydrolysis of o⁃nitrophenyl⁃β⁃D⁃galactopyranoside (oNPG).After rescreened by lactose as using lactose as substrate,strain Erwinia billingiae WX1 showed high transgalactosidation. Based on the nucleotide sequence of the β⁃galactosidase from Erwinia billingiae,the gene encoding theβ⁃galactosidase GAL was cloned and expressed in Escherichia coli. The gene consists of 1 428 bp,and the translated protein encodes 475 amino acids and its molecular mass is approximately 5�2×104. After purification,the purity of this enzyme showed that the optimal pH and temperature were 7�0 and 55 ℃,respectively. Its activity was notably promoted by Mg2+, Mn2+,whereas EDTA had high inhibition to the enzyme. The enzyme synthesis of galacto⁃oligosachorides was

  1. Legume receptors perceive the rhizobial lipochitin oligosaccharide signal molecules by direct binding

    DEFF Research Database (Denmark)

    Broghammer, Angelique; Krusell, Lene; Blaise, Mickaël;

    2012-01-01

    , and NFR1 protein retained its in vitro kinase activity. Processing of NFR5 protein was characterized by determining the N-glycosylation patterns of the ectodomain. Two different glycan structures with identical composition, Man(3)XylFucGlcNAc(4), were identified by mass spectrometry and located at...... amino acid positions N68 and N198. Receptor-ligand interaction was measured by using ligands that were labeled or immobilized by application of chemoselective chemistry at the anomeric center. High-affinity ligand binding was demonstrated with both solid-phase and free solution techniques. The K...

  2. Synthesis of N-protected Galactosamine Building Blocks from D-Tagatose via the Heyns Rearrangement

    DEFF Research Database (Denmark)

    Wrodnigg, Tanja M.; Lundt, Inge; Stütz, Arnold E.

    2006-01-01

    N-Acetyl-D-galactosamine (11), a very important naturally occurring building block of oligosaccharides, is easily accessible via the Heyns rearrangement of D-tagatose (3) with benzylamine. The short and efficient synthesis of various differently N-protected D-galactosamine derivatives is reported....

  3. Structure elucidation of two novel yak milk oligosaccharides and their DFT studies

    Science.gov (United States)

    Singh, Ashish Kumar; Ranjan, Ashok Kr.; Srivastava, Gaurav; Deepak, Desh

    2016-03-01

    Milk is a primary dynamic biological fluid responsible for development of neonates. Besides the other regular constituents it have oligosaccharides in it which are responsible for antitumor, anticancer, antigenic and immunostimulant activities. In our endeavor to find biologically active novel oligosaccharides, yak milk was taken, which is a rich source of oligosaccharide and its milk is used as antihypertensive, antioxidative and heart strengthening agent in folk medicine. For this purpose yak milk was processed by method of Kobata and Ginsburg followed by gel filtration HPLC and CC which resulted in the isolation of two novel milk oligosaccharides namely (I) Grunniose and (II) Vakose. The structure of purified milk oligosaccharides were elucidated with the help of chemical degradation, chemical transformation, spectroscopic techniques like NMR (1H, 13C and 2D-NMR), structure reporter group theory and mass spectrometry. The optimized geometry of compound Grunniose and Vakose, at B3LYP method and 6-311 + G basis set on Gaussian 09 program, show that the compound Grunniose is lower in energy as compared to compound Vakose.

  4. [Study on intestinal absorption features of oligosaccharides in Morinda officinalis How. with sigle-pass perfusion].

    Science.gov (United States)

    Deng, Shao-Dong; Zhang, Peng; Lin, Li; Xiao, Feng-Xia; Lin, Jing-Ran

    2015-01-01

    To study the in situ intestinal absorption of five oligosaccharides contained in Morinda officinalis How. (sucrose, kestose, nystose, 1F-Fructofuranosyinystose and Bajijiasu). The absorption of the five oligosaccharides in small intestine (duodenum, jejunum and ileum) and colon of rats and their contents were investigated by using in situ single-pass perfusion model and HPLC-ELSD. The effects of drug concentration, pH in perfusate and P-glycoprotein inhibitor on the intestinal absorption were investigated to define the intestinal absorption mechanism of the five oligosaccharides in rats. According to the results, all of the five oligosaccharides were absorbed in the whole intestine, and their absorption rates were affected by the pH of the perfusion solution, drug concentration and intestinal segments. Verapamil Hydrochloride could significantly increase the absorptive amount of sucrose and Bajijiasu, suggesting sucrose and Bajijiasu are P-gp's substrate. The five oligosaccharides are absorbed mainly through passive diffusion in the intestinal segments, without saturated absorption. They are absorbed well in all intestines and mainly in duodenum and jejunum.

  5. Oligosaccharide binding proteins from Bifidobacterium longum subsp. infantis reveal a preference for host glycans.

    Directory of Open Access Journals (Sweden)

    Daniel Garrido

    Full Text Available Bifidobacterium longum subsp. infantis (B. infantis is a common member of the infant intestinal microbiota, and it has been characterized by its foraging capacity for human milk oligosaccharides (HMO. Its genome sequence revealed an overabundance of the Family 1 of solute binding proteins (F1SBPs, part of ABC transporters and associated with the import of oligosaccharides. In this study we have used the Mammalian Glycan Array to determine the specific affinities of these proteins. This was correlated with binding protein expression induced by different prebiotics including HMO. Half of the F1SBPs in B. infantis were determined to bind mammalian oligosaccharides. Their affinities included different blood group structures and mucin oligosaccharides. Related to HMO, other proteins were specific for oligomers of lacto-N-biose (LNB and polylactosamines with different degrees of fucosylation. Growth on HMO induced the expression of specific binding proteins that import HMO isomers, but also bind blood group and mucin oligosaccharides, suggesting coregulated transport mechanisms. The prebiotic inulin induced other family 1 binding proteins with affinity for intestinal glycans. Most of the host glycan F1SBPs in B. infantis do not have homologs in other bifidobacteria. Finally, some of these proteins were found to be adherent to intestinal epithelial cells in vitro. In conclusion, this study represents further evidence for the particular adaptations of B. infantis to the infant gut environment, and helps to understand the molecular mechanisms involved in this process.

  6. [Study on intestinal absorption features of oligosaccharides in Morinda officinalis How. with sigle-pass perfusion].

    Science.gov (United States)

    Deng, Shao-Dong; Zhang, Peng; Lin, Li; Xiao, Feng-Xia; Lin, Jing-Ran

    2015-01-01

    To study the in situ intestinal absorption of five oligosaccharides contained in Morinda officinalis How. (sucrose, kestose, nystose, 1F-Fructofuranosyinystose and Bajijiasu). The absorption of the five oligosaccharides in small intestine (duodenum, jejunum and ileum) and colon of rats and their contents were investigated by using in situ single-pass perfusion model and HPLC-ELSD. The effects of drug concentration, pH in perfusate and P-glycoprotein inhibitor on the intestinal absorption were investigated to define the intestinal absorption mechanism of the five oligosaccharides in rats. According to the results, all of the five oligosaccharides were absorbed in the whole intestine, and their absorption rates were affected by the pH of the perfusion solution, drug concentration and intestinal segments. Verapamil Hydrochloride could significantly increase the absorptive amount of sucrose and Bajijiasu, suggesting sucrose and Bajijiasu are P-gp's substrate. The five oligosaccharides are absorbed mainly through passive diffusion in the intestinal segments, without saturated absorption. They are absorbed well in all intestines and mainly in duodenum and jejunum. PMID:25993803

  7. An important developmental role for oligosaccharides during early embryogenesis of cyprinid fish.

    Science.gov (United States)

    Bakkers, J; Semino, C E; Stroband, H; Kijne, J W; Robbins, P W; Spaink, H P

    1997-07-22

    Derivatives of chitin oligosaccharides have been shown to play a role in plant organogenesis at nanomolar concentrations. Here we present data which indicate that chitin oligosaccharides are important for embryogenesis in vertebrates. We characterize chitin oligosaccharides synthesized in vitro by zebrafish and carp embryos in the late gastrulation stage by incorporation of radiolabeled N-acetyl-D-[U14C]glucosamine and by HPLC in combination with enzymatic conversion using the Bradyrhizobium NodZ alpha-1, 6-fucosyltransferase and chitinases. A rapid and sensitive bioassay for chitin oligosaccharides was also used employing suspension-cultured plant cells of Catharanthus roseus. We show that chitin oligosaccharide synthase activity is apparent only during late gastrulation and can be inhibited by antiserum raised against the Xenopus DG42 protein. The DG42 protein, a glycosyltransferase, is transiently expressed between midblastula and neurulation in Xenopus and zebrafish embryogenesis. Microinjection of the DG42 antiserum or the Bradyrhizobium NodZ enzyme in fertilized eggs of zebrafish led to severe defects in trunk and tail development.

  8. α-1,6-Mannosylation of N-Linked Oligosaccharide Present on Cell Wall Proteins Is Required for Their Incorporation into the Cell Wall in the Filamentous Fungus Neurospora crassa▿†

    OpenAIRE

    Maddi, Abhiram; Free, Stephen J.

    2010-01-01

    The enzyme α-1,6-mannosyltransferase (OCH-1) is required for the synthesis of galactomannans attached to the N-linked oligosaccharides of Neurospora crassa cell wall proteins. The Neurospora crassa och-1 mutant has a tight colonial phenotype and a defective cell wall. A carbohydrate analysis of the och-1 mutant cell wall revealed a 10-fold reduction in the levels of mannose and galactose and a total lack of 1,6-linked mannose residues. Analysis of the integral cell wall protein from wild-type...

  9. Understanding sugar yield loss and enzyme inhibition due to oligosaccharides accumulation during high solids-loading enzymatic hydrolisis.

    Science.gov (United States)

    During enzymatic hydrolysis of biomass, polysaccharides are cleaved by glycosyl hydrolases to soluble oligosaccharides and further hydrolyzed by ß-glucosidase, ß-xylosidase and other enzymes to monomeric sugars. However, not all oligosaccharides can be fully hydrolyzed and they may accumulate to 18-...

  10. The Effect of Neutral Oligosaccharides on Reducing the Incidence of Necrotizing Enterocolitis in Preterm infants: A Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Amir-Mohammad Armanian

    2014-01-01

    Conclusions: Enteral supplementation with prebiotic significantly reduced the incidence of NEC in VLBW infants who were fed exclusively breast-milk. This finding suggests that it might have been the complete removal of formula which caused a synergistic effect between nonhuman neutral oligosaccharides (prebiotic and human oligosaccharides.

  11. Galacto‐oligosaccharides attenuate renal injury with microbiota modification

    Science.gov (United States)

    Furuse, Satoshi U.; Ohse, Takamoto; Jo‐Watanabe, Airi; Shigehisa, Akira; Kawakami, Koji; Matsuki, Takahiro; Chonan, Osamu; Nangaku, Masaomi

    2014-01-01

    Abstracts Tubulointerstitial injury is central to the progression of end‐stage renal disease. Recent studies have revealed that one of the most investigated uremic toxins, indoxyl sulfate (IS), caused tubulointerstitial injury through oxidative stress and endoplasmic reticulum (ER) stress. Because indole, the precursor of IS, is synthesized from dietary tryptophan by the gut microbiota, we hypothesized that the intervention targeting the gut microbiota in kidney disease with galacto‐oligosaccharides (GOS) would attenuate renal injury. After 2 weeks of GOS administration for 5/6 nephrectomized (Nx) or sham‐operated (Sham) rats, cecal indole and serum IS were measured, renal injury was evaluated, and the effects of GOS on the gut microbiota were examined using pyrosequencing methods. Cecal indole and serum IS were significantly decreased and renal injury was improved with decreased infiltrating macrophages in GOS‐treated Nx rats. The expression levels of ER stress markers and apoptosis were significantly increased in the Nx rats and decreased with GOS. The microbiota analysis indicated that GOS significantly increased three bacterial families and decreased five families in the Nx rats. In addition, the analysis also revealed that the bacterial family Clostridiaceae was significantly increased in the Nx rats compared with the Sham rats and decreased with GOS. Taken altogether, our data show that GOS decreased cecal indole and serum IS, attenuated renal injury, and modified the gut microbiota in the Nx rats, and that the gut microbiota were altered in kidney disease. GOS could be a novel therapeutic agent to protect against renal injury. PMID:24994892

  12. Transgalactosylation and hydrolytic activities of commercial preparations of β-galactosidase for the synthesis of prebiotic carbohydrates.

    Science.gov (United States)

    Guerrero, Cecilia; Vera, Carlos; Conejeros, Raúl; Illanes, Andrés

    2015-03-01

    β-Galactosidases exhibit both hydrolytic and transgalactosylation activities; the former has been used traditionally for the production of delactosed milk and dairies, while the latter is being increasingly used for the synthesis of lactose-derived oligosaccharides: balance between both activities was highly dependent on the enzyme origin: β-galactosidases from Aspegillus oryzae and Bacillus circulans exhibited high transgalactosylation activity, while those from one from Kluyveromyces exhibited high hydrolytic activity but quite low transgalactosylation activity. Also the affinity for the donors (lactose or lactulose) and the acceptors (lactose, lactulose or fructose) of transgalactosylated galactose was dependent on the enzyme origin, as reflected by the Michaelis constants obtained in the synthesis of galacto-oligosaccharides, fructosyl-galacto-oligosaccharides and lactulose. Finally, the balance between transgalactosylation and hydrolytic activities of β-galactosidases could be tuned by changing the concentration of galactose donor.

  13. Isolation, structure elucidation and DFT study on two novel oligosaccharides from yak milk

    Science.gov (United States)

    Singh, Meenakshi; Kumar, Alok; Srivastava, Gaurav; Deepak, Desh; Singh, M. P. V. V.

    2016-08-01

    Two novel oligosaccharides were isolated from yak milk. The milk was processed by the method of Kobata and Ginsberg involving deproteination, centrifugation and lyophilization followed by gel filtrate chromatography acetylation and silica gel column chromatography of derivatized oligosaccharides while their homogeneity was confirmed by HPLC. The structures of these isolated oligosaccharides were elucidated by chemical transformation, chemical degradation, 1H, 13C NMR, 2D NMR (COSY, TOCSY and HSQC) and mass spectrometry. The geometry of compound A (Bosiose) and B (Bovisose) have been optimized at B3LYP method and 6-311 + G(d,p) basis set. The difference between the energies of A and B is 1.269 a.u. or 796.309 kcal/mol.

  14. Total Synthesis of Plakilactones C, B and des-Hydroxyplakilactone B by the Oxidative Cleavage of Gracilioether Furanylidenes.

    Science.gov (United States)

    Norris, Matthew D; Perkins, Michael V

    2016-08-01

    A chemoselective oxidative cleavage of synthetic gracilioether B, 11-epi-gracilioether C benzoate, and des-hydroxygracilioether C with pyridinium chlorochromate, which proceeds with loss of the furanyl acetate, has enabled total synthesis and stereochemical elucidation of the marine sponge metabolites (4R,6R)-plakilactone C, (4R,6R,9R)-plakilactone B, and (4R,6R)-des-hydroxyplakilactone B. des-Hydroxygracilioether C, the putative biosynthetic precursor to hippolachnin A, was also found to undergo a facile ene cyclization on treatment with SnCl4. PMID:27359169

  15. Anti-infective bovine colostrum oligosaccharides: Campylobacter jejuni as a case study.

    Science.gov (United States)

    Lane, Jonathan A; Mariño, Karina; Naughton, Julie; Kavanaugh, Devon; Clyne, Marguerite; Carrington, Stephen D; Hickey, Rita M

    2012-07-01

    Campylobacter jejuni is the leading cause of acute bacterial infectious diarrhea in humans. Unlike in humans, C. jejuni is a commensal within the avian host. Heavily colonized chickens often fail to display intestinal disease, and no cellular attachment or invasion has been demonstrated in-vivo. Recently, researchers have shown that the reason for the attenuation of C. jejuni virulence may be attributed to the presence of chicken intestinal mucus and more specifically chicken mucin. Since mucins are heavily glycosylated molecules this observation would suggest that glycan-based compounds may act as anti-infectives against C. jejuni. Considering this, we have investigated naturally sourced foods for potential anti-infective glycans. Bovine colostrum rich in neutral and acidic oligosaccharides has been identified as a potential source of anti-infective glycans. In this study, we tested oligosaccharides isolated and purified from the colostrum of Holstein Friesian cows for anti-infective activity against a highly invasive strain of C. jejuni. During our initial studies we structurally defined 37 bovine colostrum oligosaccharides (BCO) by HILIC-HPLC coupled with exoglycosidase digests and off-line mass spectroscopy, and demonstrated the ability of C. jejuni to bind to some of these structures, in-vitro. We also examined the effect of BCO on C. jejuni adhesion to, invasion of and translocation of HT-29 cells. BCO dramatically reduced the cellular invasion and translocation of C. jejuni, in a concentration dependent manner. Periodate treatment of the BCO prior to inhibition studies resulted in a loss of the anti-infective activity of the glycans suggesting a direct oligosaccharide-bacterial interaction. This was confirmed when the BCO completely prevented C. jejuni binding to chicken intestinal mucin, in-vitro. This study builds a strong case for the inclusion of oligosaccharides sourced from cow's milk in functional foods. However, it is only through further

  16. A new method for the chemoselective reduction of aldehydes and ketones using boron tri-isopropoxide, B(OPr)3: Comparison with boron tri-ethoxide, B(OEt)3

    Indian Academy of Sciences (India)

    Burcu Uysal; Birsen S Oksal

    2011-09-01

    A chemoselective Meerwein-Ponndorf-Verley reduction process of various aliphatic and allylic ,-unsaturated aldehydes and ketones is described. This chemoselective reduction is catalysed by boron triisopropoxide B(OPr)3. Kinetics of reduction of aldehydes and ketones to corresponding alcohols were also examined and rate constant of each carbonyl compounds were measured. Rate constant and reduction yield of each carbonyl compounds in the presence of B(OPr)3 were compared with those in the presence of B(OEt)3. The alcohols that are the reduction product were analysed by GC-MS. The rate constants and alcohol yields were found to be higher with B(OEt)3 than with B(OPr)3. The mechanism proposed involves a six-membered transition state in which both the alcohol and the carbonyl are coordinated to the same boron centre of a boron alkoxide catalyst.

  17. Cyclitols, galactosyl cyclitols and raffinose family oligosaccharides in Mexican wild lupin seeds

    Directory of Open Access Journals (Sweden)

    Agnieszka I. Piotrowicz-Cieślak

    2011-04-01

    Full Text Available Ten to 16 ethanol-soluble carbohydrate components were identified in the seeds of six Mexican wild lupins. The analysed carbohydrates included: monosaccharides, disaccharides, cyclitols, galactosyl cyclitols and raffinose family oligosaccharides. Stachyose and sucrose were the main carbohydrate component in the Lupinus montanus, L. rotundiflorus, L. exaltatus, L. mexicanus and L. elegans seeds. Only trace quantities of verbascose were detected in Lupinus mexicanus seeds. The analysed seeds accumulated 38 to 78 mg/g d.m. carbohydrates. The raffinose family oligosaccharides constituted 41 to 85.2% of the identified carbohydrate component pool. The analysed Lupinus seeds contained 3 to 8 unidentified carbohydrate components.

  18. Simultaneous analysis of monosaccharides and oligosaccharides by high-performance liquid chromatography with postcolumn fluorescence derivatization.

    Science.gov (United States)

    Kakita, Hirotaka; Kamishima, Hiroshi; Komiya, Katsuo; Kato, Yoshio

    2002-06-28

    To develop a fluorimetric HPLC technique for the simultaneous microanalysis of reducing mono- and oligosaccharides, the technique of linear gradient elution was introduced into the postcolumn fluorimetric detemination system of reducing saccharides with benzamidine. Fluorescence measurement was performed at 288 nm for excitation and 470 nm for emission and an optimization study for this postcolumn fluorescence derivatization carried out. Under optimum conditions, the detection limits of D-glucose and maltohexaose were 1.78 and 2.59 pmol, respectively. The present method was successfully applied to saccharide analysis and should prove useful for automated simultaneous microanalysis of reducing mono- and oligosaccharides in foods. PMID:12186393

  19. The application of HP-GFC chromatographic method for the analysis of oligosaccharides in bioactive complexes

    Directory of Open Access Journals (Sweden)

    Savić Ivan

    2009-01-01

    Full Text Available The aim of this work was to optimize a GFC method for the analysis of bioactive metal (Cu, Co and Fe complexes with olygosaccharides (dextran and pullulan. Bioactive metal complexes with olygosaccharides were synthesized by original procedure. GFC was used to study the molecular weight distribution, polymerization degree of oligosaccharides and bioactive metal complexes. The metal bounding in complexes depends on the ligand polymerization degree and the presence of OH groups in coordinative sphere of the central metal ion. The interaction between oligosaccharide and metal ions are very important in veterinary medicine, agriculture, pharmacy and medicine.

  20. Presence of inulin-type fructo-oligosaccharides and shift from raffinose family oligosaccharide to fructan metabolism in leaves of boxtree (Buxus sempervirens

    Directory of Open Access Journals (Sweden)

    Wim eVan den Ende

    2016-03-01

    Full Text Available from raffinose family oligosaccharide to fructan metabolism in leaves of boxtree (Buxus sempervirens Wim Van den Ende1,* Marlies Coopman1, Rudy Vergauwen1, André Van Laere11 KU Leuven, Laboratory of Molecular Plant Biology, Institute of Botany and Microbiology, Kasteelpark Arenberg 31, B-3001 Leuven, Belgium* Correspondence: Wim Van den Ende, Laboratory of Molecular Plant Biology,Institute of Botany and Microbiology, Kasteelpark Arenberg 31, B-3001 Leuven, Belgium tel +32 16321952; fax +32 16321967;Wim.vandenende@bio.kuleuven.beKeywords: inulin, oligosaccharides, stress, RFO, fructanAbstractFructans are known to occur in 15% of flowering plants and their accumulation is often associated with stress responses. Typically, particular fructan types occur within particular plant families. The family of the Buxaceae, harbouring Pachysandra terminalis, an accumulator of graminan- and levan-type fructans, also harbours boxtree (Buxus sempervirens, a cold and drought tolerant species. Surprisingly, boxtree leaves do not accumulate the expected graminan- and levan-type fructans but small inulin fructo-oligosaccharides (FOS: 1-kestotriose and nystose and raffinose family oligosaccharides (RFO: raffinose and stachyose instead. The seasonal variation in concentrations of glucose, fructose, sucrose, FOS and RFO were followed. Raffinose and stachyose peaked during the winter months, while FOS peaked at a very narrow time-interval in spring, immediately preceded by a prominent sucrose accumulation. Sucrose may function as a reserve carbohydrate in winter and early spring leaves. The switch from RFO to fructan metabolism in spring strongly suggests that fructan and RFO fulfil distinct roles in boxtree leaves. RFO may play a key role in the cold acclimation of winter leaves while temporal fructan biosynthesis in spring might increase sink strength to sustain the formation of new shoots.

  1. Chemically defined diet alters the protective properties of fructo-oligosaccharides and isomalto-oligosaccharides in HLA-B27 transgenic rats.

    Directory of Open Access Journals (Sweden)

    Petya Koleva

    Full Text Available Non-digestible oligosaccharides (NDO were shown to reduce inflammation in experimental colitis, but it remains unclear whether microbiota changes mediate their colitis-modulating effects. This study assessed intestinal microbiota and intestinal inflammation after feeding chemically defined AIN-76A or rat chow diets, with or without supplementation with 8 g/kg body weight of fructo-oligosaccharides (FOS or isomalto-oligosaccharides (IMO. The study used HLA-B27 transgenic rats, a validated model of inflammatory bowel disease (IBD, in a factorial design with 6 treatment groups. Intestinal inflammation and intestinal microbiota were analysed after 12 weeks of treatment. FOS and IMO reduced colitis in animals fed rat chow, but exhibited no anti-inflammatory effect when added to AIN-76A diets. Both NDO induced specific but divergent microbiota changes. Bifidobacteria and Enterobacteriaceae were stimulated by FOS, whereas copy numbers of Clostridium cluster IV were decreased. In addition, higher concentrations of total short-chain fatty acids (SCFA were observed in cecal contents of rats on rat chow compared to the chemically defined diet. AIN-76A increased the relative proportions of propionate, iso-butyrate, valerate and iso-valerate irrespective of the oligosaccharide treatment. The SCFA composition, particularly the relative concentration of iso-butyrate, valerate and iso-valerate, was associated (P ≤ 0.004 and r ≥ 0.4 with increased colitis and IL-1 β concentration of the cecal mucosa. This study demonstrated that the protective effects of fibres on colitis development depend on the diet. Although diets modified specific cecal microbiota, our study indicates that these changes were not associated with colitis reduction. Intestinal inflammation was positively correlated to protein fermentation and negatively correlated with carbohydrate fermentation in the large intestine.

  2. Novel process for the coproduction of xylo-oligosaccharides, fermentable sugars, and lignosulfonates from hardwood.

    Science.gov (United States)

    Huang, Caoxing; Jeuck, Ben; Du, Jing; Yong, Qiang; Chang, Hou-Min; Jameel, Hasan; Phillips, Richard

    2016-11-01

    Many biorefineries have not been commercialized due to poor economic returns from final products. In this work, a novel process has been developed to coproduce valuable sugars, xylo-oligosaccharides, and lignosulfonates from hardwood. The modified process includes a mild autohydrolysis pretreatment, which enables for the recovery of the xylo-oligosaccharides in auto-hydrolysate. Following enzymatic hydrolysis, the residue is sulfomethylated to produce lignosulfonates. Recycling the sulfomethylation residues increased both the glucan recovery and lignosulfonate production. The glucose recovery was increased from 81.7% to 87.9%. Steady state simulation using 100g of hardwood produced 46.7g sugars, 5.9g xylo-oligosaccharides, and 25.7g lignosulfonates, which were significantly higher than that produced from the no-recycling process with 39.1g sugars, 5.9g xylo-oligosaccharides, and 15.0g lignosulfonates. The results indicate that this novel biorefinery process can improve the production of fermentable sugars and lignosulfonate from hardwood as compared to a conventional biorefinery process. PMID:27543951

  3. Capillary Electrophoresis-Mass Spectrometry for the Analysis of Heparin Oligosaccharides and Low Molecular Weight Heparin.

    Science.gov (United States)

    Sun, Xiaojun; Lin, Lei; Liu, Xinyue; Zhang, Fuming; Chi, Lianli; Xia, Qiangwei; Linhardt, Robert J

    2016-02-01

    Heparins, highly sulfated, linear polysaccharides also known as glycosaminoglycans, are among the most challenging biopolymers to analyze. Hyphenated techniques in conjunction with mass spectrometry (MS) offer rapid analysis of complex glycosaminoglycan mixtures, providing detailed structural and quantitative data. Previous analytical approaches have often relied on liquid chromatography (LC)-MS, and some have limitations including long separation times, low resolution of oligosaccharide mixtures, incompatibility of eluents, and often require oligosaccharide derivatization. This study examines the analysis of glycosaminoglycan oligosaccharides using a novel electrokinetic pump-based capillary electrophoresis (CE)-MS interface. CE separation and electrospray were optimized using a volatile ammonium bicarbonate electrolyte and a methanol-formic acid sheath fluid. The online analyses of highly sulfated heparin oligosaccharides, ranging from disaccharides to low molecular weight heparins, were performed within a 10 min time frame, offering an opportunity for higher-throughput analysis. Disaccharide compositional analysis as well as top-down analysis of low molecular weight heparin was demonstrated. Using normal polarity CE separation and positive-ion electrospray ionization MS, excellent run-to-run reproducibility (relative standard deviation of 3.6-5.1% for peak area and 0.2-0.4% for peak migration time) and sensitivity (limit of quantification of 2.0-5.9 ng/mL and limit of detection of 0.6-1.8 ng/mL) could be achieved.

  4. Secretion and apparent activation of human hepatic lipase requires proper oligosaccharide processing in the endoplasmic reticulum

    NARCIS (Netherlands)

    A.J.M. Verhoeven (Adrie); B.P. Neve (Bernadette); H. Jansen (Hans)

    1999-01-01

    textabstractHuman hepatic lipase (HL) is a glycoprotein with four N-linked oligosaccharide side chains. The importance of glycosylation for the secretion of catalytically active HL was studied in HepG2 cells by using inhibitors of intracellular trafficking, N-glycosylat

  5. Tracking developmentally regulated post-synthetic processing of homogalacturonan and chitin using reciprocal oligosaccharide probes

    DEFF Research Database (Denmark)

    Mravec, Jozef; Kračun, Stjepan K.; Rydahl, Maja G.;

    2014-01-01

    is limited by a lack of suitable molecular tools. Here, we report the development of a novel non-immunological approach for producing highly selective reciprocal oligosaccharide-based probes for chitosan (the product of chitin deacetylation) and for demethylesterified homogalacturonan. Specific reciprocal...

  6. Is there a role for oligosaccharides in seed longevity? An assessment of intracellular glass stability

    NARCIS (Netherlands)

    Buitink, J.; Hemminga, M.A.; Hoekstra, F.A.

    2000-01-01

    We examined whether oligosaccharides extend seed longevity by increasing the intracellular glass stability. For that purpose, we used a spin probe technique to measure the molecular mobility and glass transition temperature of the cytoplasm of impatiens (Impatiens walleriana) and bell pepper (Capsic

  7. A snapshot into the metabolism of isomalto-oligosaccharides in probiotic bacteria

    DEFF Research Database (Denmark)

    Abou Hachem, Maher; Møller, Marie Sofie; Andersen, Joakim Mark;

    2013-01-01

    -04, respectively. Utilization of IMO and malto-oligosaccharide (α-(1,4)-glucosides) appears to be linked both at the genetic and transcriptomic level in the acidophilus group lactobacilli as suggested by reverse transcriptase PCR (RT-PCR) and gene landscape analysis. Canonical intracellular GH13...

  8. Sugar loss and enzyme inhibition due to oligosaccharides accumulation during high solids-loading enzymatic hydrolysis

    Science.gov (United States)

    Oligosaccharide accumulation occurs during high solid loading enzymatic hydrolysis of corn stover (CS) irrespective of using different pretreated corn stover (dilute acid: DA, ionic liquids: IL, ammonia fiber expansion: AFEX and extractive ammonia: EA). The methodology for large-scale separation of ...

  9. Prebiotic oligosaccharides and the enterohepatic circulation of bile salts in rats

    NARCIS (Netherlands)

    H. van Meer (Hester); G. Boehm (Günther); F. Stellaard (Frans); A. Vriesema (Aldwin); J. Knol (Jan); R. Havinga (Rick); P.J.J. Sauer (Pieter); H.J. Verkade (Henkjan)

    2008-01-01

    textabstractHuman milk contains prebiotic oligosaccharides, which stimulate the growth of intestinal bifidobacteria and lactobacilli. It is unclear whether the prebiotic capacity of human milk contributes to the larger bile salt pool size and the more efficient fat absorption in infants fed human mi

  10. Prebiotic oligosaccharides and the enterohepatic circulation of bile salts in rats

    NARCIS (Netherlands)

    van Meer, Hester; Boehm, Gunther; Stellaard, Frans; Vriesema, Aldwin; Knol, Jan; Havinga, Rick; Sauer, Pieter J.; Verkade, Henkjan J.

    2008-01-01

    Human milk contains prebiotic oligosaccharides, which stimulate the growth of intestinal bifidobacteria and lactobacilli. It is unclear whether the prebiotic capacity of human milk contributes to the larger bile salt pool size and the more efficient fat absorption in infants fed human milk compared

  11. Intestinal fermentation of lactose and prebiotic lactose derivatives, including human milk oligosaccharides

    NARCIS (Netherlands)

    Venema, K.

    2012-01-01

    This review describes the recent advances in technology to study fermentation of lactose and its prebiotic derivatives, including human milk oligosaccharides. Novel molecular tools to identify members of the microbiota that ferment these substrates are highlighted, as well as the use of stable isoto

  12. Prebiotic potential of pectins and pectic oligosaccharides derived from lemon peel wastes and sugar beet pulp

    NARCIS (Netherlands)

    Gómez, Belén; Gullón, Beatriz; Yáñez, Remedios; Schols, Henk; Alonso, José L.

    2016-01-01

    Sugar beet pulp (SBP) and lemon peel wastes (LPW) were used to obtain two mixtures of pectic oligosaccharides (denoted as SBPOS and LPOS, respectively). Oligogalacturonides in LPOS showed a larger molecular weight, higher degree of methylation and lower degree of acetylation than the ones in SBPO

  13. The antioxidant effects of complexes of tilapia fish skin collagen and different marine oligosaccharides

    Science.gov (United States)

    Ren, Shuwen; Li, Jing; Guan, Huashi

    2010-12-01

    An excess of reactive oxygen species (ROS) leads to a variety of chronic health problems. As potent antioxidants, marine bioactive extracts containing oligosaccharides and peptides have been extensively studied. Recently, there is a growing interest in protein-polysaccharide complexes because of their potential uses in pharmaceutical and food industries. However, only few studies are available on the antioxidant activities of such complexes, in terms of their ROS scavenging capability. In this study, we combined different marine oligosaccharides (isolated and purified) with collagen peptides derived from tilapia fish skin, and evaluated the antioxidant activity of the marine peptide-oligosaccharide complexes vis-à-vis the activity of their original component molecules. Biochemical and cellular assays were performed to measure the scavenging effects on 1, 1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and superoxide radicals, and to evaluate the influences on the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and the level of malondialdehyde (MDA) in UV-induced photoaging models. The results indicated that the antioxidant activities of all the complexes were stronger than those of their individual components. Among the 11 complexes tested, two complexes, namely MA1000+CP and κ-ca3000+CP, turned out to be highly effective antioxidants. Although the detailed mechanisms of this improved scavenging ability are not fully understood, this work provides insights into the design of highly efficient peptide-oligosaccharide complexes for potential applications in pharmaceutical, cosmetics and food industries.

  14. Purification, Characterization, and Prebiotic Properties of Pectic Oligosaccharides from Orange Peel Wastes

    NARCIS (Netherlands)

    Gómez, B.; Gullón, B.; Remoroza, C.A.; Schols, H.A.; Parajó, J.C.; Alonso, J.L.

    2014-01-01

    Pectic oligosaccharides (POS) were obtained by hydrothermal treatment of orange peel wastes (OPW) and purified by membrane filtration to yield a refined product containing 90 wt % of the target products. AraOS (DP 3–21), GalOS (DP 5–12), and OGalA (DP 2–12, with variable DM) were identified in POS m

  15. Oligosaccharides Might Contribute to the Antidiabetic Effect of Honey: A Review of the Literature

    Directory of Open Access Journals (Sweden)

    Mohd S. Ab Wahab

    2011-12-01

    Full Text Available Evidence shows that honey improves glycemic control in diabetes mellitus. Besides its hypoglycemic effect, studies indicate that honey ameliorates lipid abnormalities in rats and humans with diabetes. The majority of these studies do not examine the mechanisms by which honey ameliorates glycemic and/or lipid derangements. The gut microbiota is now recognized for its ability to increase energy harvest from the diet and alter lipid metabolism of the host. Recently available data implicate a causal role of these gut microbes in the pathophysiology of obesity, insulin resistance, and diabetes mellitus. In this review, we present some of the latest findings linking gut microbiota to pathogenesis of obesity, insulin resistance, and diabetes mellitus. The review also underlines data that demonstrate the beneficial effects of oligosaccharides on various abnormalities commonly associated with these disorders. Based on the similarities of some of these findings with those of honey, together with the evidence that honey contains oligosaccharides, we hypothesize that oligosaccharides present in honey might contribute to the antidiabetic and other health-related beneficial effects of honey. We anticipate that the possibility of oligosaccharides in honey contributing to the antidiabetic and other health-related effects of honey will stimulate a renewed research interest in this field.

  16. Effect of oligosaccharides on the adhesion of gut bacteria to human HT-29 cells.

    Science.gov (United States)

    Altamimi, M; Abdelhay, O; Rastall, R A

    2016-06-01

    The influence of five oligosaccharides (cellobiose, stachyose, raffinose, lactulose and chito-oligosaccharides) on the adhesion of eight gut bacteria (Bifidobacterium bifidum ATCC 29521, Bacteroides thetaiotaomicron ATCC 29148D-5, Clostridium leptum ATCC 29065, Blautia coccoides ATCC 29236, Faecalibacterium prausnitzii ATCC 27766, Bacteroides fragilis ATCC 23745, Clostridium difficile ATCC 43255 and Lactobacillus casei ATCC 393) to mucous secreting and non-mucous secreting HT-29 human epithelial cells, was investigated. In pure culture, the bacteria showed variations in their ability to adhere to epithelial cells. The effect of oligosaccharides diminished adhesion and the presence of mucus played a major factor in adhesion, likely due to high adhesiveness to mucins present in the native human mucus layer covering the whole cell surface. However, clostridia displayed almost the same level of adhesion either with or without mucus being present. Bl. coccoides adhesion was decreased by stachyose and cellobiose in non-mucus-secreting cells in pure culture, while in mixed faecal culture cellobiose displayed the highest antiadhesive activity with an overall average of 65% inhibition amongst tested oligomers and lactulose displayed the lowest with an average of 47.4%. Bifidobacteria, Bacteroides, lactobacilli and clostridia were inhibited within the following ranges 47-78%, 32-65%, 11.7-58% and 64-85% respectively. This means that clostridia were the most strongly influenced members of the microflora amongst the bacterial groups tested in mixed culture. In conclusion, introducing oligosaccharides which are candidate prebiotics into pure or mixed cultures has affected bacterial adhesion. PMID:27018325

  17. Consumption of Breads Containing In Situ-Produced Arabinoxylan Oligosaccharides Alters Gastrointestinal Effects in Healthy Volunteers

    NARCIS (Netherlands)

    Damen, Bram; Cloetens, Lieselotte; Broekaert, Willem F.; Francois, Isabelle; Lescroart, Olivier; Trogh, Isabel; Arnaut, Filip; Welling, Gjalt W.; Wijffels, Jan; Delcour, Jan A.; Verbeke, Kristin; Courtin, Christophe M.

    2012-01-01

    Arabinoxylan oligosaccharides (AXOS) are studied as food compounds with prebiotic potential. Here, the impact of consumption of breads with in situ-produced AXOS on intestinal fermentation and overall gastrointestinal characteristics was evaluated in a completely randomized, double-blind, controlled

  18. Lysosomal storage of oligosaccharide and glycosphingolipid in imino sugar treated cells.

    Science.gov (United States)

    Boomkamp, Stephanie D; Rountree, J S Shane; Neville, David C A; Dwek, Raymond A; Fleet, George W J; Butters, Terry D

    2010-04-01

    Sandhoff and Tay-Sachs disease are autosomal recessive GM2 gangliosidoses where a deficiency of lysosomal beta-hexosaminidase results in storage of glycoconjugates. Imino sugar (2-acetamido-1,4-imino-1,2,4-trideoxy-L-arabinitol) inhibition of beta-hexosaminidase in murine RAW264.7 macrophage-like cells led to lysosomal storage of glycoconjugates that were characterised structurally using fluorescence labelling of the free or glycolipid-derived oligosaccharides followed by HPLC and mass spectrometry. Stored glycoconjugates were confirmed as containing non-reducing GlcNAc or GalNAc residues resulting from the incomplete degradation of N-linked glycoprotein oligosaccharide and glycolipids, respectively. When substrate reduction therapeutics N-butyl-deoxynojirimycin (NB-DNJ) or N-butyldeoxygalactonojirimycin (NB-DGJ) were applied to the storage phenotype cells, an increase in glucosylated and galactosylated oligosaccharide species was observed due to endoplasmic reticulum alpha-glucosidases and lysosomal beta-galactosidase inhibition, respectively. Hexosaminidase inhibition triggered a tightly regulated cytokine-mediated inflammatory response that was normalised using imino sugars NB-DNJ and NB-DGJ, which restored the GM2 ganglioside storage burden but failed to reduce the levels of GA2 glycolipid or glycoprotein-derived N-linked oligosaccharides. Using a chemically induced gangliosidosis phenotype that can be modulated with substrate lowering drugs, the critical role of GM2 ganglioside in the progression of inflammatory disease is also demonstrated. PMID:20186478

  19. Enzymatic generation of galactose-rich oligosaccharides/oligomers from potato rhamnogalacturonan I pectic polysaccharides.

    Science.gov (United States)

    Khodaei, Nastaran; Karboune, Salwa

    2016-04-15

    Potato pulp by-product rich in galactan-rich rhamnogalacturonan I (RG I) was investigated as a new source of oligosaccharides with potential prebiotic properties. The efficiency of selected monocomponent enzymes and multi-enzymatic preparations to generate oligosaccharides/oligomers from potato RG I was evaluated. These overall results of yield were dependent on the activity profile of the multi-enzymatic preparations. Highest oligo-RG I yield of 93.9% was achieved using multi-enzymatic preparation (Depol 670L) with higher hydrolytic activity toward side chains of RG I as compared to its backbone. Main oligo-RG I products were oligosaccharides with DP of 2-12 (79.8-100%), while the oligomers with DP of 13-70 comprised smaller proportion (0.0-20.2%). Galactose (58.9-91.2%, w/w) was the main monosaccharide of oligo-RG I, while arabinose represented 0.0-12.1%. An understanding of the relationship between the activity profile of multi-enzymatic preparations and the yield/DP of oligo-RG I was achieved. This is expected to provide the capability to generate galacto- and galacto(arabino) oligosaccharides and their corresponding oligomers from an abundant by-product. PMID:26616968

  20. Biosynthesis of fructo-oligosaccharides by Sporotrichum thermophile during submerged batch cultivation in high sucrose media

    DEFF Research Database (Denmark)

    Katapodis, P.; Kalogeris, E.; Kekos, D.;

    2004-01-01

    Biosynthesis of fructo-oligosaccharides (FOS) was observed during growth of the thermophilic fungus Sporotrichum thermophile on media containing high sucrose concentrations. Submerged batch cultivation with the optimum initial sucrose concentration of 250 g/l allowed the production of 12.5 g FOS...

  1. Production of xylo-oligosaccharides from Miscanthus x giganteus by autohydrolysis

    NARCIS (Netherlands)

    Ligero, P.; Kolk, van der J.C.; Vega, de A.; Dam, van J.E.G.

    2011-01-01

    Xylo-oligosaccharides were obtained from Miscanthus x giganteus. The process was designed as a biorefinery scheme, which seeks the separation of the three main components: cellulose, hemicelluloses, and lignin. To extract the hemicelluloses, particularly xylans, in an efficient way, Miscanthus was s

  2. Intestinal microbiology in early life: Specific prebiotics can have similar functionalities as human-milk oligosaccharides

    NARCIS (Netherlands)

    R. Oozeer (Raish); K. van Limpt (Kees); T. Ludwig (Thomas); K.B. Amor (Kaouther); R. Martin (Rocio); R.D. Wind (Richèle); G. Boehm (Günther); J. Knol (Jan)

    2013-01-01

    textabstractHuman milk is generally accepted as the best nutrition for newborns and has been shown to support the optimal growth and development of infants. On the basis of scientific insights from human-milk research, a specific mixture of nondigestible oligosaccharides has been developed, with the

  3. Characterisation of branched gluco-oligosaccharides to study the mode-of-action of a glucoamylase from Hypocrea jecorina.

    Science.gov (United States)

    Jonathan, M C; van Brussel, M; Scheffers, M S; Kabel, M A

    2015-11-01

    In the conversion of starch to fermentable glucose for bioethanol production, hydrolysis of amylopectin by α-amylases and glucoamylases is the slowest step. In this process, α-1,6-branched gluco-oligosaccharides accumulate and are slowly degraded. Glucoamylases that are able to degrade such branched oligosaccharides faster are economically beneficial. This research aimed at the isolation and characterisation of branched gluco-oligosaccharides produced from amylopectin digestion by α-amylase, to be used as substrates for comparing their degradation by glucoamylases. Branched gluco-oligosaccharides with a DP between five and twelve were purified using size exclusion chromatography. These structures were characterised after labelling with 2-aminobenzamide using UHPLC-MS(n) analysis. Further, the purified oligosaccharides were used to evaluate the mode-of-action of a glucoamylase from Hypocrea jecorina. The enzyme cleaves the α-1,4-linkage adjacent to the α-1,6-linkage at a lower rate than that of α-1,4-linkages in linear oligosaccharides. Hence, the branched gluco-oligosaccharides are a suitable substrate to evaluate glucoamylase activity on branched structures. PMID:26256324

  4. The use of dead-end and cross-flow nanofiltration to purify prebiotic oligosaccharides from reaction mixtures

    Directory of Open Access Journals (Sweden)

    Alistair S. Grandison

    2002-11-01

    Full Text Available Nanofiltration (NF of model sugar solutions and commercial oligosaccharide mixtures were studied in both dead-end and cross-flow modes. Preliminary trials, with a dead-end filtration cell, demonstrated the feasibility of fractionating monosaccharides from disaccharides and oligosaccharides in mixtures, using loose nanofiltration (NF-CA-50, NF-TFC-50 membranes. During the nanofiltration purification of a commercial oligosaccharide mixture, yields of 19% (w w-1 for the monosaccharides and 88% (w w-1 for di, and oligosaccharides were obtained for the NF-TFC-50 membrane after four filtration steps, indicating that removal of the monosaccharides is possible, with only minor losses of the oligosaccharide content of the mixture. The effects of pressure, feed concentration, and filtration temperature were studied in similar experiments carried out in a cross-flow system, in full recycle mode of operation. The rejection rates of the sugar components increased with increasing pressure, and decreased with both increasing total sugar concentration in the feed and increasing temperature. Continuous diafiltration (CD purification of model sugar solutions and commercial oligosaccharide mixtures using NF-CA-50 (at 25oC and DS-5-DL (at 60oC membranes, gave yield values of 14 to 18% for the monosaccharide, 59 to 89% for the disaccharide and 81 to 98% for the trisaccharide present in the feed. The study clearly demonstrates the potential of cross flow nanofiltration in the purification of oligosaccharide mixtures from the contaminant monosaccharides.

  5. Xyloglucan oligosaccharides promote growth and activate cellulase: Evidence for a role of cellulase in cell expansion. [Pisum sativum L

    Energy Technology Data Exchange (ETDEWEB)

    McDougall, G.J.; Fry, S.C. (Univ. of Edinburgh (England))

    1990-07-01

    Oligosaccharides produced by the action of fungal cellulase on xyloglucans promoted the elongation of etiolated pea (Pisum sativum L.) stem segments in a straight-growth bioassay designed for the determination of auxins. The oligosaccharides were most active at about 1 micromolar. We tested the relative growth-promoting activities of four HPLC-purified oligosaccharides which shared a common glucose{sub 4} {center dot} xylose{sub 3} (XG7) core. The substituted oligosaccharides XG8 (glucose{sub 4} {center dot} xylose{sub 3} {center dot} galactose) and XG9n (glucose{sub 4} {center dot} xylose{sub 3} {center dot} galactose{sub 2}) were more effective than XG7 itself and XG9 (glucose{sub 4} {center dot} xylose{sub 3} {center dot} galactose {center dot} fucose). The same oligosaccharides also promoted the degradation, assayed viscometrically, of xyloglucan by an acidic cellulase from bean (Phaseolus vulgaris L.) leaves. The oligosaccharides were highly active at 10{sup {minus}4} molar, causing up to a fourfold increase in activity, but the effect was still detectable at 1 micromolar. Those oligosaccharides (XG8 and XG9n) which best promoted growth, stimulated cellulase activity to the greatest extent. The oligosaccharides did not stimulate the action of the cellulase in an assay based on the conversion of ({sup 3}H)xyloglucan to ethanol-soluble fragments. This suggests that the oligosaccharides enhanced the midchain hydrolysis of xyloglucan molecules (which would rapidly reduce the viscosity of the solution), at the expense of cleavage near the termini (which would yield ethanol-soluble products).

  6. Characterization of N-linked oligosaccharides in chorion peroxidase of Aedes aegypti mosquito.

    Science.gov (United States)

    Li, Junsuo S; Li, Jianyong

    2005-09-01

    A peroxidase is present in the chorion of Aedes aegypti eggs and catalyzes chorion protein cross-linking during chorion hardening, which is critical for egg survival in the environment. The unique chorion peroxidase (CPO) is a glycoprotein. This study deals with the N-glycosylation site, structures, and profile of CPO-associated oligosaccharides using mass spectrometric techniques and enzymatic digestion. CPO was isolated from chorion by solubilization and several chromatographic methods. Mono-saccharide composition was analyzed by HPLC with fluorescent detection. Our data revealed that carbohydrate (D-mannose, N-acetyl D-glucosamine, D-arabinose, N-acetyl D-galactosamine, and L-fucose) accounted for 2.24% of the CPO molecular weight. A single N-glycosylation site (Asn328-Cys- Thr) was identified by tryptic peptide mapping and de novo sequencing of native and PNGase A-deglycosylated CPO using matrix-assisted laser/desorption/ionization time-of-flight mass spectrometry (MALDI/TOF/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS). The Asn328 was proven to be a major fully glycosylated site. Potential tryptic glycopeptides and profile were first assessed by MALDI/TOF/MS and then by precursor ion scanning during LC/MS/MS. The structures of N-linked oligosaccharides were elucidated from the MS/MS spectra of glycopeptides and exoglycosidase sequencing of PNGase A-released oligosaccharides. These CPO-associated oligosaccharides had dominant Man3GlcNAc2 and Man3 (Fuc) GlcNAc2 and high mannose-type structures (Man(4-8)GlcNAc2). The truncated structures, Man2GlcNAc2 and Man2 (Fuc) GlcNAc2, were also identified. Comparison of CPO activity and Stokes radius between native and deglycosylated CPO suggests that the N-linked oligosaccharides influence the enzyme activity by stabilizing its folded state.

  7. Prebiotic oligosaccharides change the concentrations of short-chain fatty acids and the microbial population of mouse bowel

    Institute of Scientific and Technical Information of China (English)

    Xiao-dong PAN; Fen-qin CHEN; Tian-xing WU; Hong-gang TANG; Zhan-yu ZHAO

    2009-01-01

    The purpose of this study was to clarify effects of selected oligosaccharides on concentrations of cecal short-chain fatty acids (SCFAs), total large bowel wet weight and wall weight, and cecal microbiota levels in mice. Mice were respectively given gavage of selected fructooligosaccharides (FOS), galactooligosaccharides (GOS), mannanoligosaccharides (MOS), and chitooligosaccharides (COS) [1000 mg/(kg body weight.d)]. Control group was given physiological saline solution. After 14 d treatment, SCFAs and lactate in mice cecum were significantly increased (P<0.05) by intake of oligosaccharides, especially FOS and GOS. Thus, providing these oligosaccharides as ingredients in nutritional formulas may benefit the gastrointestinal tract.

  8. Glycosyl hydrolases from Bifidobacterium adolescentis DSM20083 : Their role in the metabolism and synthesis of oligosaccharides.

    NARCIS (Netherlands)

    Broek, van den L.A.M.

    2005-01-01

    Tegenwoordig is er een toenemende vraag en interesse voor gezondheidsbevorderende voeding voor de mens. Prebiotica worden bijvoorbeeld gebruikt voor het stimuleren van de groei van bacteriën in de darm die een positieve invloed hebben op de gezondheid van de mens. Geclaimd wordt dat bifidobacteriën

  9. Efficient chemoenzymatic oligosaccharide synthesis by reverse phosphorolysis using cellobiose phosphorylase and cellodextrin phosphorylase from Clostridium thermocellum

    DEFF Research Database (Denmark)

    Nakai, Hiroyuki; Abou Hachem, Maher; Petersen, Bent O.;

    2010-01-01

    Inverting cellobiose phosphorylase (CtCBP) and cellodextrin phosphorylase (CtCDP) from Clostridium thermocellum ATCC27405 of glycoside hydrolase family 94 catalysed reverse phosphorolysis to produce cellobiose and cellodextrins in 57% and 48% yield from α-d-glucose 1-phosphate as donor with gluco...

  10. Synthesis of the Oligosaccharide Fragment of the Surface of TumorCell and Its Analogue

    Institute of Scientific and Technical Information of China (English)

    QinZhihui; ZhangLihe; LiZhongjun

    2001-01-01

    Selectins are a new class of carbohydrate-binding glycoproteins which have been identified on the surface ofspecific cell types, such as leukocytes,platelets and vascular endothelium.It is now known that the selectin-carbohydrate recognition not only play key roles at early stage of the inflammatory reaction,but also are very important for the invasion and metastasis of tumors.

  11. In vivo imaging of hydrogen peroxide production in a murine tumor model with a chemoselective bioluminescent reporter

    OpenAIRE

    Van de Bittner, Genevieve C.; Dubikovskaya, Elena A.; Bertozzi, Carolyn R.; Chang, Christopher J.

    2010-01-01

    Living organisms produce hydrogen peroxide (H2O2) to kill invading pathogens and for cellular signaling, but aberrant generation of this reactive oxygen species is a hallmark of oxidative stress and inflammation in aging, injury, and disease. The effects of H2O2 on the overall health of living animals remain elusive, in part owing to a dearth of methods for studying this transient small molecule in vivo. Here we report the design, synthesis, and in vivo applications of Peroxy Caged Luciferin-...

  12. Th1-directing adjuvants increase the immunogenicity of oligosaccharide-protein conjugate vaccines related to Streptococcus pneumoniae type 3

    NARCIS (Netherlands)

    Lefeber, DJ; Benaissa-Trouw, B; Vliegenthart, JFG; Kamerling, JP; Jansen, WTM; Kraaijeveld, K; Snippe, H

    2003-01-01

    Oligosaccharide (OS)-protein conjugates are promising candidate vaccines against encapsulated bacteria, such as Haemophilus influenzae, Neisseria meningitidis, and Streptococcus pneumoniae. Although the effects of several variables such as OS chain length and protein carrier have been studied, littl

  13. New type of adhesive specificity revealed by oligosaccharide probes in Escherichia coli from patients with urinary tract infection.

    Science.gov (United States)

    Rosenstein, I J; Stoll, M S; Mizuochi, T; Childs, R A; Hounsell, E F; Feizi, T

    1988-12-10

    A series of oligosaccharides derived from glycoproteins or from human milk were coupled to lipid and used as probes of the binding specificities of Escherichia coli isolated from patients with urinary tract infections. Selective binding to the glycoprotein oligosaccharide probes rich in mannose residues (high-mannose type) was demonstrated with fimbriated E coli that give mannose-inhibitable haemagglutination. This observation is in accordance with predictions from inhibition studies. Binding studies with the human milk oligosaccharide probes, which resemble structures found on host-cell membranes, revealed adhesive specificity unrelated to the presence of fimbriae. This new type of host oligosaccharide receptor is affected by the presence of the blood group genetic markers. It involves the disaccharide sequence linked to the membrane-associated lipid moiety of host-cell glycolipids, and may have a role in initiation of infection on damaged epithelial cell membranes.

  14. Characterization of oligosaccharide structures on a chimeric respiratory syncytial virus protein expressed in insect cell line Sf9

    Energy Technology Data Exchange (ETDEWEB)

    Wathen, M.W.; Aeed, P.A.; Elhammer, A.P. (Upjohn Co., Kalamazoo, MI (United States))

    1991-03-19

    The oligosaccharide structures added to a chimeric protein (FG) composed of the extracellular domains of respiratory syncytial virus F and G proteins, expressed in the insect cell line Sf9, were investigated. Cells were labeled in vivo with ({sup 3}H)glucosamine and infected wit a recombinant baculovirus containing the FG gene. The secreted chimeric protein was isolated by immunoprecipitation and subjected to oligosaccharide analysis. The FG protein contains two types of O-linked oligosaccharides: GalNAc and Gal{beta}1-3GalNAc constituting 17 and 66% of the total number of structures respectively. Only one type of N-linked oligosaccharide, constituting the remaining 17% of the structures on FG, was detected: a trimannosyl core structure with a fucose residue linked {alpha}1-6 to the asparagine-linked N-acetylglucosamine.

  15. Generation and structural validation of a library of diverse xyloglucan-derived oligosaccharides, including an update on xyloglucan nomenclature.

    Science.gov (United States)

    Tuomivaara, Sami T; Yaoi, Katsuro; O'Neill, Malcolm A; York, William S

    2015-01-30

    Xyloglucans are structurally complex plant cell wall polysaccharides that are involved in cell growth and expansion, energy metabolism, and signaling. Determining the structure-function relationships of xyloglucans would benefit from the availability of a comprehensive and structurally diverse collection of rigorously characterized xyloglucan oligosaccharides. Here, we present a workflow for the semi-preparative scale generation and purification of neutral and acidic xyloglucan oligosaccharides using a combination of enzymatic and chemical treatments and size-exclusion chromatography. Twenty-six of these oligosaccharides were purified to near homogeneity and their structures validated using a combination of matrix-assisted laser desorption/ionization mass spectrometry, high-performance anion exchange chromatography, and 1H nuclear magnetic resonance spectroscopy. Mass spectrometry and analytical chromatography were compared as methods for xyloglucan oligosaccharide quantification. 1H chemical shifts were assigned using two-dimensional correlation spectroscopy. A comprehensive update of the nomenclature describing xyloglucan side-chain structures is provided for reference. PMID:25497333

  16. Transcriptional response of HT-29 intestinal epithelial cells to human and bovine milk oligosaccharides.

    Science.gov (United States)

    Lane, Jonathan A; O'Callaghan, John; Carrington, Stephen D; Hickey, Rita M

    2013-12-01

    Human milk oligosaccharides (HMO) have been shown to interact directly with immune cells. However, large quantities of HMO are required for intervention or clinical studies, but these are unavailable in most cases. In this respect, bovine milk is potentially an excellent source of commercially viable analogues of these unique molecules. In the present study, we compared the transcriptional response of colonic epithelial cells (HT-29) to the entire pool of HMO and bovine colostrum oligosaccharides (BCO) to determine whether the oligosaccharides from bovine milk had effects on gene expression that were similar to those of their human counterparts. Gene set enrichment analysis of the transcriptional data revealed that there were a number of similar biological processes that may be influenced by both treatments including a response to stimulus, signalling, locomotion, and multicellular, developmental and immune system processes. For a more detailed insight into the effects of milk oligosaccharides, the effect on the expression of immune system-associated glycogenes was chosen as a case study when performing validation studies. Glycogenes in the current context are genes that are directly or indirectly regulated in the presence of glycans and/or glycoconjugates. RT-PCR analysis revealed that HMO and BCO influenced the expression of cytokines (IL-1β, IL-8, colony-stimulating factor 2 (granulocyte-macrophage) (GM-CSF2), IL-17C and platelet factor 4 (PF4)), chemokines (chemokine (C-X-C motif) ligand 1 (CXCL1), chemokine (C-X-C motif) ligand 3 (CXCL3), chemokine (C-C motif) ligand 20 (CCL20), chemokine (C-X-C motif) ligand 2 (CXCL2), chemokine (C-X-C motif) ligand 6 (CXCL6), chemokine (C-C motif) ligand 5 (CCL5), chemokine (C-X3-C motif) ligand 1 (CX3CL1) and CXCL2) and cell surface receptors (interferon γ receptor 1 (IFNGR1), intercellular adhesion molecule-1 (ICAM-1), intercellular adhesion molecule-2 (ICAM-2) and IL-10 receptor α (IL10RA)). The present study suggests

  17. Structure Analysis and Ion Abundance in CID- MS- MS Spectra of Isomeric Oligosaccharides Using Quadrupole Time-of- flight Mass Spectrometry: Distinguishing between Isomeric Oligosaccharides

    Institute of Scientific and Technical Information of China (English)

    Tohru YAMAGAKI; Kazuo TACHIBANA

    2001-01-01

    @@ N - Linked oligosaccharide were analyzed by using electrospray ionization (ESI) quadrupole time - of- fight mass spectrometry(Q - Tof MS).The isomers showed the same MS and collisioninduced desociation(CID) MS - MS spectra in the m/z values because the sequence of the sugar residues was the same.But the relative ion abundance of the specific fragment ion was greatly different between the isomers.So, the isomeric oligosacchariedes were distinguished by using the ion abundance in their CID -MS - MS spectra.Discussing the ion abundance in accurate level, quantitative analysis of the mixtures of isomers were also performed.

  18. Detection and Quantitation of Afucosylated N-Linked Oligosaccharides in Recombinant Monoclonal Antibodies Using Enzymatic Digestion and LC-MS

    Science.gov (United States)

    Du, Yi; May, Kimberly; Xu, Wei; Liu, Hongcheng

    2012-07-01

    The presence of N-linked oligosaccharides in the CH2 domain has a significant impact on the structure, stability, and biological functions of recombinant monoclonal antibodies. The impact is also highly dependent on the specific oligosaccharide structures. The absence of core-fucose has been demonstrated to result in increased binding affinity to Fcγ receptors and, thus, enhanced antibody-dependent cellular cytotoxicity (ADCC). Therefore, a method that can specifically determine the level of oligosaccharides without the core-fucose (afucosylation) is highly desired. In the current study, recombinant monoclonal antibodies and tryptic peptides from the antibodies were digested using endoglycosidases F2 and H, which cleaves the glycosidic bond between the two primary GlcNAc residues. As a result, various oligosaccharides of either complex type or high mannose type that are commonly observed for recombinant monoclonal antibodies are converted to either GlcNAc residue only or GlcNAc with the core-fucose. The level of GlcNAc represents the sum of all afucosylated oligosaccharides, whereas the level of GlcNAc with the core-fucose represents the sum of all fucosylated oligosaccharides. LC-MS analysis of the enzymatically digested antibodies after reduction provided a quick estimate of the levels of afucosylation. An accurate determination of the level of afucosylation was obtained by LC-MS analysis of glycopeptides after trypsin digestion.

  19. N-linked oligosaccharide in MSP-1 and its implication for scallop calcification

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We speculated the structure of the N-linked oligosaccharides enzymatically released from the organic matrix (OM) component in the foliated layer of Patinopecten yessoensis.The 80 kDa component of the soluble OM was detected by lectin blotting and was identified as MSP-1 using liquid chromatography/mass spectrometry (LC/MS/MS).LC/MS/MS analysis of the N-glycan liberated from MSP-1 detected a hybrid-type N-glycan,which contained sulfite and sialic acid at its terminus based on the characteristic Y ions.The data strongly imply that MSP-1,a sulfated OM glycoprotein,participates in molluscan biomineralization by creating a favorable environment for calcium ion uptake through sulfite acid and sialic acid.Further analyses of oligosaccharides linked to the OM components in wide variety of species and shell microstructures may definitely contribute in elucidation of molluscan biomineralization at the molecular level.

  20. Structure of the oligosaccharides isolated from Prosopis juliflora (Sw.) DC. seed polysaccharide.

    Science.gov (United States)

    Bhatia, Himani; Gupta, P K; Soni, P L

    2014-01-30

    A water soluble polysaccharide isolated from Prosopis juliflora seed was purified and major homogenous fraction obtained by GPC. Complete hydrolysis of the polysaccharide followed by paper chromatography and GLC analysis indicated the presence of d-galactose and d-mannose in the ratio 1:1.10, respectively. Partial hydrolysis of the polysaccharide furnished one hepta-(I), one octa-(II) and nona-(III) saccharides. Hydrolysis of oligosaccharide I, II and III followed by GLC analysis furnished d-galactose and d-mannose in the ratio 3:4, 3:5 and 5:4, respectively. Methylation analysis, periodate oxidation and (1)H NMR spectral studies of oligosaccharides indicated the presence of (1→4) mannose units linked to (1→6) galactose units.

  1. Novel identification strategy for ground coffee adulteration based on UPLC-HRMS oligosaccharide profiling.

    Science.gov (United States)

    Cai, Tie; Ting, Hu; Jin-Lan, Zhang

    2016-01-01

    Coffee is one of the most common and most valuable beverages. According to International Coffee Organization (ICO) reports, the adulteration of coffee for financial reasons is regarded as the most serious threat to the sustainable development of the coffee market. In this work, a novel strategy for adulteration identification in ground coffee was developed based on UPLC-HRMS oligosaccharide profiling. Along with integrated statistical analysis, 17 oligosaccharide composition were identified as markers for the identification of soybeans and rice in ground coffee. This strategy, validated by manual mixtures, optimized both the reliability and authority of adulteration identification. Rice and soybean adulterants present in ground coffee in amounts as low as 5% were identified and evaluated. Some commercial ground coffees were also successfully tested using this strategy.

  2. Genome Structure of the Symbiont Bifidobacterium pseudocatenulatum CECT 7765 and Gene Expression Profiling in Response to Lactulose-Derived Oligosaccharides.

    Science.gov (United States)

    Benítez-Páez, Alfonso; Moreno, F Javier; Sanz, María L; Sanz, Yolanda

    2016-01-01

    Bifidobacterium pseudocatenulatum CECT 7765 was isolated from stools of a breast-fed infant. Although, this strain is generally considered an adult-type bifidobacterial species, it has also been shown to have pre-clinical efficacy in obesity models. In order to understand the molecular basis of its adaptation to complex carbohydrates and improve its potential functionality, we have analyzed its genome and transcriptome, as well as its metabolic output when growing in galacto-oligosaccharides derived from lactulose (GOS-Lu) as carbon source. B. pseudocatenulatum CECT 7765 shows strain-specific genome regions, including a great diversity of sugar metabolic-related genes. A preliminary and exploratory transcriptome analysis suggests candidate over-expression of several genes coding for sugar transporters and permeases; furthermore, five out of seven beta-galactosidases identified in the genome could be activated in response to GOS-Lu exposure. Here, we also propose that a specific gene cluster is involved in controlling the import and hydrolysis of certain di- and tri-saccharides, which seemed to be those primarily taken-up by the bifidobacterial strain. This was discerned from mass spectrometry-based quantification of different saccharide fractions of culture supernatants. Our results confirm that the expression of genes involved in sugar transport and metabolism and in the synthesis of leucine, an amino acid with a key role in glucose and energy homeostasis, was up-regulated by GOS-Lu. This was done using qPCR in addition to the exploratory information derived from the single-replicated RNAseq approach, together with the functional annotation of genes predicted to be encoded in the B. pseudocatenulatum CETC 7765 genome. PMID:27199952

  3. Genome Structure of the Symbiont Bifidobacterium pseudocatenulatum CECT 7765 and Gene Expression Profiling in Response to Lactulose-Derived Oligosaccharides

    Science.gov (United States)

    Benítez-Páez, Alfonso; Moreno, F. Javier; Sanz, María L.; Sanz, Yolanda

    2016-01-01

    Bifidobacterium pseudocatenulatum CECT 7765 was isolated from stools of a breast-fed infant. Although, this strain is generally considered an adult-type bifidobacterial species, it has also been shown to have pre-clinical efficacy in obesity models. In order to understand the molecular basis of its adaptation to complex carbohydrates and improve its potential functionality, we have analyzed its genome and transcriptome, as well as its metabolic output when growing in galacto-oligosaccharides derived from lactulose (GOS-Lu) as carbon source. B. pseudocatenulatum CECT 7765 shows strain-specific genome regions, including a great diversity of sugar metabolic-related genes. A preliminary and exploratory transcriptome analysis suggests candidate over-expression of several genes coding for sugar transporters and permeases; furthermore, five out of seven beta-galactosidases identified in the genome could be activated in response to GOS-Lu exposure. Here, we also propose that a specific gene cluster is involved in controlling the import and hydrolysis of certain di- and tri-saccharides, which seemed to be those primarily taken-up by the bifidobacterial strain. This was discerned from mass spectrometry-based quantification of different saccharide fractions of culture supernatants. Our results confirm that the expression of genes involved in sugar transport and metabolism and in the synthesis of leucine, an amino acid with a key role in glucose and energy homeostasis, was up-regulated by GOS-Lu. This was done using qPCR in addition to the exploratory information derived from the single-replicated RNAseq approach, together with the functional annotation of genes predicted to be encoded in the B. pseudocatenulatum CETC 7765 genome. PMID:27199952

  4. New approaches to enzymatic glycoside synthesis through directed evolution.

    Science.gov (United States)

    Kittl, Roman; Withers, Stephen G

    2010-07-01

    The expanding field of glycobiology requires tools for the synthesis of structurally defined oligosaccharides and glycoconjugates, while any potential therapeutic applications of sugar-based derivates would require access to substantial quantities of such compounds. Classical chemical approaches are not well suited for such large-scale syntheses, thus enzymatic approaches are sought. Traditional routes to the enzymatic assembly of oligosaccharides have involved the use of either Nature's own biosynthetic enzymes, the glycosyl transferases, or glycosidases run in transglycosylation mode. However, each approach has drawbacks that have limited its application. Glycosynthases are mutant glycosidases in which the catalytic nucleophile has been replaced by mutation, inactivating them as hydrolases. When used in conjunction with glycosyl fluorides of the opposite anomeric configuration to that of the substrate, these enzymes function as highly efficient transferases, frequently giving stoichiometric yields of products. Further improvements can be obtained through directed evolution of the gene encoding the enzyme in question, but this requires the ability to screen very large libraries of catalysts. In this review we survey new screening methods for the formation of glycosidic linkages using high-throughput techniques, such as FACS, chemical complementation, and robot-assisted ELISA assays. Enzymes were evolved to have higher catalytic activity with their natural substrates, to show altered substrate specificities or to be promiscuous for efficient application in oligosaccharide, glycolipid, and glycoprotein synthesis. PMID:20427037

  5. Coupling Flash LC with MS for enrichment and isolation of milk oligosaccharides for functional studies

    OpenAIRE

    Strum, John S.; Aldredge, Danielle; Barile, Daniela; Lebrilla, Carlito B.

    2012-01-01

    Mass spectrometry has been coupled with flash liquid chromatography to yield new capabilities for isolating non-chromophoric material from complicated biological mixtures. A flash LC/MS/MS method enabled fraction collection of milk oligosaccharides from biological mixtures based on composition and structure. The method is compatible with traditional gas-pressure driven flow flash chromatography, widely employed in organic chemistry laboratories. The on-line mass detector enabled real-time opt...

  6. Studies on production of fructo-oligosaccharides (FOS) by gamma radiation processing of microbial levin

    International Nuclear Information System (INIS)

    Microbial levan produced using Bacillus megaterium type 1, was subjected to graded doses of gamma radiation as well as acid hydrolysis. No significant degradation was observed in irradiated levan powder upto 150 kGy. Irradiation of aqueous 10% levan solution by 60Co source at a dose of 250 kGy yielded 63% fructo-oligosaccharides (FOS) with an average mol. wt. of 1250 D. (author)

  7. Arabinoxylan Oligosaccharide Hydrolysis by Family 43 and 51 Glycosidases from Lactobacillus brevis DSM 20054

    OpenAIRE

    Michlmayr, Herbert; Hell, Johannes; Lorenz, Cindy; Böhmdorfer, Stefan; Rosenau, Thomas; Kneifel, Wolfgang

    2013-01-01

    Due to their potential prebiotic properties, arabinoxylan-derived oligosaccharides [(A)XOS] are of great interest as functional food and feed ingredients. While the (A)XOS metabolism of Bifidobacteriaceae has been extensively studied, information regarding lactic acid bacteria (LAB) is still limited in this context. The aim of the present study was to fill this important gap by characterizing candidate (A)XOS hydrolyzing glycoside hydrolases (GHs) identified in the genome of Lactobacillus bre...

  8. The principal fucosylated oligosaccharides of human milk exhibit prebiotic properties on cultured infant microbiota

    OpenAIRE

    Yu, Zhuo-Teng; Chen, Ceng; Kling, David E.; Liu, Bo; McCoy, John M; Merighi, Massimo; Heidtman, Matthew; Newburg, David S.

    2012-01-01

    Breast-fed infant microbiota is typically rich in bifidobacteria. Herein, major human milk oligosaccharides (HMOS) are assessed for their ability to promote the growth of bifidobacteria and to acidify their environment, key features of prebiotics. During in vitro anaerobic fermentation of infant microbiota, supplementation by HMOS significantly decreased the pH even greater than supplementation by fructooligosaccharide (FOS), a prebiotic positive control. HMOS elevated lactate concentrations,...

  9. Effects of Maillard reaction conditions on the functional properties of WPI chitosan oligosaccharide conjugates

    OpenAIRE

    Zheng, Zhe; Luo, Yongkang; Yao, Lei; Lu, Jing; Bu, Guanhao

    2013-01-01

    Whey proteins are widely used as food material, but their functional properties are affected by processing conditions, in which Maillard reaction commonly occurs. The objective of this study was to investigate the effects of reaction conditions (saccharide rate (SR), setting time and setting temperature) on the functional properties of conjugates of whey protein isolates (WPI) - chitosan oligosaccharide (COS), which were produced by Maillard reaction. Response surface methodology (RSM) was us...

  10. Study on Oligosaccharides from Morinda officinalis%巴戟天寡糖研究

    Institute of Scientific and Technical Information of China (English)

    冯峰; 王羚郦; 赖小平; 李远彬; 曹志梅; 周应军

    2012-01-01

    Objective: To study the oligosaccharides from Morinda officinalis How. Methods: Compounds were isolated by chroma-tography, and their structures were identified by spectral analysis and chemical evidences. Results: six compounds were isolated and i-dentified as sucrose( I ) , inulin-type trisaecharide( II ) , inulin-type hexasaccharide( III) , inulotriose( IV) , inulotetraose( V ) , inu-lopentaose( VI).Conclusion: Compound IV ,V and VI are isolated from Morinda officinalis for the first time. Morinda officinalis How; Oligosaccharides; Inulin-type oligosaccharide; Inulo-type oligosaccharide%目的:对巴戟天(Morinda officinalis)的糖类成分进行化学研究.方法:用活性炭、纤维素和硅胶等色谱法分离,用波谱法对化合物结构进行鉴定.结果:从巴戟天活性部位中分离出6个寡糖类化合物,分别为蔗糖(Ⅰ)、耐斯糖(Ⅱ)、菊粉六糖(Ⅲ)、β-D-果吡喃糖-(2→1)-β-D-果呋喃糖-(2→1)-β-D-果呋喃糖(Ⅳ)、β-D-果吡喃糖-(2→1) -β-D-果呋喃糖-(2→1)-β-D-果呋喃糖-(2→1)-β-D-果呋喃糖(Ⅴ)、β-D-果吡喃糖-(2→1)-β-D-果呋喃糖-( 2→1)-β-D-果呋喃糖-(2→1)-β-D-果呋喃糖-(2→1)-β-D-果呋喃糖(Ⅵ).结论:化合物Ⅳ-Ⅵ为首次从巴戟天属中分离出的化合物.

  11. Identification of yeast genes that confer resistance to chitosan oligosaccharide (COS) using chemogenomics

    OpenAIRE

    Jaime Maria DLA; Lopez-Llorca Luis; Conesa Ana; Lee Anna Y; Proctor Michael; Heisler Lawrence E; Gebbia Marinella; Giaever Guri; Westwood J; Nislow Corey

    2012-01-01

    Background: Chitosan oligosaccharide (COS), a deacetylated derivative of chitin, is an abundant, and renewable natural polymer. COS has higher antimicrobial properties than chitosan and is presumed to act by disrupting/permeabilizing the cell membranes of bacteria, yeast and fungi. COS is relatively non-toxic to mammals. By identifying the molecular and genetic targets of COS, we hope to gain a better understanding of the antifungal mode of action of COS. Results: Three different chemogenomic...

  12. Effect of mannan oligosaccharides on the ileal morphometry and cecal fermentation of growing rabbits

    OpenAIRE

    Pinheiro, V.M; Alves, A; Mourão, J.L.; Guedes, C.M.; Pinto, L; Spring, P; Kocher, A

    2004-01-01

    A common problem in rabbits is the occurrence of digestive disorders just after weaning. This problem is usually associated with instability of the cecal microflora and characterized by diarrhea, loss of appetite and increased mortality. In the current study the effects of a mannan oligosaccharide (MOS, Bio-MOS ® , Alltech Inc. USA) was compared to a commonly used antibiotic (AGP, Zn-Bacitracin). The current study investigated the effects of MOS and AGP on intestinal morphometry and cecal VF...

  13. Variation of fibrinogen oligosaccharide structure in the acute phase response: Possible haemorrhagic implications

    Directory of Open Access Journals (Sweden)

    Stephen O. Brennan

    2015-06-01

    Conclusions and implications: The failure of incorporation Gal excludes the possibility of the hepatic NAcNeu Gal transferase capping the oligosaccharides with sialic acid. This has two desirable haemostatic outcomes: fibrin monomers will polymerise and form clots more rapidly, and two galactose residues can never be exposed diminishing uptake of the protein by the asialoglycoprotein receptor and ramping up concentration at a time of challenge.

  14. Effects of Mannan Oligosaccharide and Saccharomyces cerevisiae on Gut Morphology of Broiler Chickens

    OpenAIRE

    Veena Pani Padihari; Sita Prasad Tiwari; Tarini Sahu; Manoj Kumar Gendley; Surendra Kumar Naik

    2014-01-01

    150 day old Vencobb broiler chicks were randomly allocated to 5 treatment groups with 3 replicates of 10 chicks in each to determine the effect of mannan oligosaccharide (MOS) and Saccharomyces cerevisiae in gut morphology of broilers. The trial lasted for 6 weeks. For microscopic examination the representative samples of each segment of intestine were collected and fixed in the 10% buffered formalin. No significant difference was observed in treatments at length of different segments of int...

  15. Inhibition of allergic airway responses by heparin derived oligosaccharides: identification of a tetrasaccharide sequence

    Directory of Open Access Journals (Sweden)

    Ahmed Tahir

    2012-01-01

    Full Text Available Abstract Background Previous studies showed that heparin's anti-allergic activity is molecular weight dependent and resides in oligosaccharide fractions of Objective To investigate the structural sequence of heparin's anti-allergic domain, we used nitrous acid depolymerization of porcine heparin to prepare an oligosaccharide, and then fractionated it into disaccharide, tetrasaccharide, hexasaccharide, and octasaccharide fractions. The anti-allergic activity of each oligosaccharide fraction was tested in allergic sheep. Methods Allergic sheep without (acute responder and with late airway responses (LAR; dual responder were challenged with Ascaris suum antigen with and without inhaled oligosaccharide pretreatment and the effects on specific lung resistance and airway hyperresponsiveness (AHR to carbachol determined. Additional inflammatory cell recruitment studies were performed in immunized ovalbumin-challenged BALB/C mice with and without treatment. Results The inhaled tetrasaccharide fraction was the minimal effective chain length to show anti-allergic activity. This fraction showed activity in both groups of sheep; it was also effective in inhibiting LAR and AHR, when administered after the antigen challenge. Tetrasaccharide failed to modify the bronchoconstrictor responses to airway smooth muscle agonists (histamine, carbachol and LTD4, and had no effect on antigen-induced histamine release in bronchoalveolar lavage fluid in sheep. In mice, inhaled tetrasaccharide also attenuated the ovalbumin-induced peribronchial inflammatory response and eosinophil influx in the bronchoalveolar lavage fluid. Chemical analysis identified the active structure to be a pentasulfated tetrasaccharide ([IdoU2S (1→4GlcNS6S (1→4 IdoU2S (1→4 AMan-6S] which lacked anti-coagulant activity. Conclusions These results demonstrate that heparin tetrasaccharide possesses potent anti-allergic and anti-inflammatory properties, and that the domains responsible for anti

  16. Phytic acid and raffinose series oligosaccharides metabolism in developing chickpea seeds

    OpenAIRE

    Zhawar, Vikramjit Kaur; Kaur, Narinder; Gupta, Anil Kumar

    2011-01-01

    Phytic acid and raffinose series oligosaccharides (RFOs) have anti-nutritional properties where phytic acid chelates minerals and reduces their bioavailability to humans and other animals, and RFOs cause flatulence. Both phytic acid and RFOs cannot be digested by monogastric animals and are released as pollutant-wastes. Efforts are being made to reduce the contents of these factors without affecting the viability of seeds. This will require a thorough understanding of their metabolism in diff...

  17. Fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) and nonallergic food intolerance: FODMAPs or food chemicals?

    OpenAIRE

    Barrett, Jacqueline S.; Gibson, Peter R

    2012-01-01

    Food intolerance in irritable bowel syndrome (IBS) is increasingly being recognized, with patients convinced that diet plays a role in symptom induction. Evidence is building to implicate fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) in the onset of abdominal pain, bloating, wind and altered bowel habit through their fermentation and osmotic effects. Hypersensitivity to normal levels of luminal distension is known to occur in patients with IBS, with consid...

  18. Development of approaches to a third-generation carbohydrate-conjugate vaccine against Streptococcus pneumoniae: the search for optimal oligosaccharide ligands

    Science.gov (United States)

    Gening, M. L.; Kurbatova, E. A.; Tsvetkov, Yu E.; Nifantiev, N. E.

    2015-11-01

    The review addresses the application of synthetic oligosaccharides related to fragments of capsular polysaccharides from different serotypes of the bacterium Streptococcus pneumoniae for the design of third-generation pneumococcal conjugate vaccines. Special focus is given to characteristic features of the chemical structures of oligosaccharides required for the induction of the protective immune response when using synthetic glycoconjugate vaccines based on oligosaccharide ligands and carrier proteins. The bibliography includes 101 references.

  19. Effects of Different Oligosaccharides on Performance and Availability of Nutrients in Broilers

    Institute of Scientific and Technical Information of China (English)

    GAO Ying; SHAN An-shan

    2004-01-01

    One hundred and forty-four Avin broilers (1 d of age) were randomly divided into six groups, with three replicates of eight birds each to study on the effects of different oligosaccharides on performance and availability of nutrients in broilers. The control group(Group Ⅰ)was fed with corn-soybean meal as basal diet, and the trial groups (Group Ⅱ, Ⅲ, Ⅳ,Ⅴ and Ⅵ) were fed with basal diet plus 0.1% Manoligosaccharides(MOS), 0.3% Soybean-Oligosacchacline(CTC), respectively. The results showed that the supplementation of oligosaccharides slightly improved daily gain and feed intake. SBOS supplementation improved, but MOS and α-GOS significantly decreased availability of energy.Oligosaccharides supplementation improved availability of energy, phosphorus, calcium, magnesium and iron, and significantly increased cholesterol content of fecal, and did not affect on availability of protein and cholesterol contents in serum and muscle. Availability of phosphorus of broilers fed with FOS was much higher than that with α-GOS. SBOS supplementation remarkably increased availability of iron.

  20. Human milk oligosaccharides: The role in the fine-tuning of innate immune responses.

    Science.gov (United States)

    Kulinich, Anna; Liu, Li

    2016-09-01

    In order to secure the health of newborns over the period of immune immaturity during the first months of life, a mother provides her offspring with passive protection: bioactive molecules transferred through the placenta and breast milk. It is well known that human milk contains immunoglobulins (Ig), immune cells and diverse cytokines, which affect newborn directly or indirectly and contribute to the maturation of the immune system. However, in addition to the above-stated molecules, human milk oligosaccharides (HMOs), a complex mixture of free indigestible carbohydrates with multiple functions, play exceptional roles in the functioning of the infants' immune system. These biological molecules have been studied over decades, however, interest in HMOs does not seem to have abated. Although biological activities of oligosaccharides from human milk have been explicitly reviewed, information regarding the role of HMOs in inflammation remains rather fragmented. The purpose of this review is to compile existing knowledge about the role of certain species of HMOs, including fucosylated, galactosylated and sialylated oligosaccharides, and their signaling pathways in immunity and inflammation. The advances in applying this information to the treatment of diseases in infants as well as adults were also reviewed here. PMID:27448325

  1. FNCA guideline on development of hydrogel and oligosaccharides by radiation processing

    International Nuclear Information System (INIS)

    This report summarizes the current status of development of hydrogel and oligosaccharides by radiation (electron beams and gamma rays) processing in Asian countries, as an outcome of activities of the FNCA (Forum for Nuclear Co-operation in Asia)-industry group during the phase 2 (2006-2008), as one of FNCA Guidelines. The nine countries, Bangladesh (since 2007), China, Indonesia, Japan, Korea, Malaysia, Philippines, Thailand and Vietnam, participates in the phase 2 of the FNCA-industry group, focusing on radiation processing of natural polymers. Participating countries have been studying radiation processing of natural polymers such as chitosan from shrimp/crab shells and carrageenan taken from seaweeds, in terms of cross-linking for gel and degradation for oligosaccharides. The former obtains hydrogel which can absorb a lot of water, and application for wound dressing and super water absorbent in the fields of medical and environmental conservation are expected. The latter obtained oligosaccharides have functions as growth promoter and elicitor activator of plants, sea-creatures and livestocks etc., and application in the fields of agri- and aqua- cultures are expected. This Guideline consists of 3 parts; part 1 describes the outline of radiation chemistry of polymers; part 2 compiles the protocols of versatile applications; part 3 refers the examples of cost analysis and current status of the technology. This Guideline would facilitate development, commercialization and technical transfer to end-users of radiation processing of natural polymers. (author)

  2. Pectic oligosaccharides from agricultural by-products: production, characterization and health benefits.

    Science.gov (United States)

    Babbar, Neha; Dejonghe, Winnie; Gatti, Monica; Sforza, Stefano; Elst, Kathy

    2016-08-01

    Pectin containing agricultural by-products are potential sources of a new class of prebiotics known as pectic oligosaccharides (POS). In general, pectin is made up of homogalacturonan (HG, α-1,4-linked galacturonic acid monomers) and rhamnogalacturonan (RG, alternate galacturonic acid and rhamnose backbone with neutral side chains). Controlled hydrolysis of pectin containing agricultural by-products like sugar beet, apple, olive and citrus by chemical, enzymatic and hydrothermal can be used to produce oligo-galacturonides (GalpOS), galacto-oligosaccharides (GalOS), rhamnogalacturonan-oligosaccharides (RGOS), etc. However, extensive research is needed to establish the role of POS, both as a prebiotic as well as therapeutic agent. This review comprehensively covers different facets of POS, including the nature and chemistry of pectin and POS, potential agricultural residual sources of pectin, pre-treatment methods for facilitating selective extraction of pectin, identification and characterization of POS, health benefits and important applications of POS in food and feed. This review has been compiled to establish a platform for future research in the purification and characterization of POS and for in vivo and in vitro studies of important POS, so that they could be commercially exploited. PMID:25641325

  3. Milk Proteins, Peptides, and Oligosaccharides: Effects against the 21st Century Disorders

    Directory of Open Access Journals (Sweden)

    Chia-Chien Hsieh

    2015-01-01

    Full Text Available Milk is the most complete food for mammals, as it supplies all the energy and nutrients needed for the proper growth and development of the neonate. Milk is a source of many bioactive components, which not only help meeting the nutritional requirements of the consumers, but also play a relevant role in preventing various disorders. Milk-derived proteins and peptides have the potential to act as coadjuvants in conventional therapies, addressing cardiovascular diseases, metabolic disorders, intestinal health, and chemopreventive properties. In addition to being a source of proteins and peptides, milk contains complex oligosaccharides that possess important functions related to the newborn’s development and health. Some of the health benefits attributed to milk oligosaccharides include prebiotic probifidogenic effects, antiadherence of pathogenic bacteria, and immunomodulation. This review focuses on recent findings demonstrating the biological activities of milk peptides, proteins, and oligosaccharides towards the prevention of diseases of the 21st century. Processing challenges hindering large-scale production and commercialization of those bioactive compounds have been also addressed.

  4. Low anticoagulant heparin oligosaccharides as inhibitors of BACE-1, the Alzheimer's β-secretase.

    Science.gov (United States)

    Zhang, Xiao; Zhao, Xiaoliang; Lang, Yinzhi; Li, Qinying; Liu, Xiaoxiao; Cai, Chao; Hao, Jiejie; Li, Guoyun; Yu, Guangli

    2016-10-20

    Heparin (HP) is a promising agent for anti-Alzheimer's disease (AD), but its anticoagulant activity limits its applications. So a low anticoagulant heparin (LAH) with anti-AD effect is needed. A novel LAH and heparan sulfate (HS) were purified from crude porcine intestinal heparin. Their structures were characterized by nuclear magnetic resonance and liquid chromatography-mass spectrometry. LAH had a relatively high degree of sulfation, but lower than that of HP. 3-O-Sulfated-containing glucosamine residues further confirmed the low anticoagulant activity of LAH. Sixteen oligosaccharides of LAH and HS were prepared and assigned. Evaluation of anti-BACE-1 activities suggested that their potencies were positively correlated with degree of sulfation and polymerization of oligosaccharides. Besides, LAH-derived hexa- to dodecasaccharides was promised to be administrated in vitro as BACE-1 inhibitors. This study presented ideal BACE-1 inhibitors, LAH-derived oligosaccharides, with virtually no anticoagulant activities, which were promised to be excellent leads for treatment of AD. PMID:27474542

  5. Oligosaccharide composition of the neurotoxin responsive Na+ channel and the requirement of sialic acid for activity

    International Nuclear Information System (INIS)

    The neurotoxin responsive Na+ channel was purified to homogeneity in an 18% yield from a clonal cell line of mouse neuroblastoma, N-18, metabolically labeled with L-[3H]fucose. The Na+ channel, a glycoprotein, M/sub r/=200,000 (gradient 7-14% PAGE) was digested with Pronase and the glycopeptides were characterized by serial lectin affinity chromatography. greater than 90% of the oligosaccharides contained sialic acid and 18% were biantennary, 39% were triantennary and 30% tetraantennary. The glycoprotein was reconstituted into artificial phospholipid vesicles and 86Rb flux was stimulated (65%) by 200 μM veratridine and 1.2 μg of scorpion venom and was inhibited (95%) by 5 μM tetrodotoxin. The requirement of sialic acid for Na+ channel activity was demonstrated since neuraminidase (0.01 U) treatment of the reconstituted glycoprotein eliminated the response of 86Rb flux to the stimulating neurotoxins. In other experiments, treatment of N-18 cells with 10 μM swainsonine, an inhibitor of glycoprotein processing, altered the oligosaccharide composition of the Na+ channel. When the abnormally glycosylated Na+ channel was reconstituted into artificial phospholipid vesicles, 86Rb flux in response to neurotoxins was impaired. Thus, glycosylation of the polypeptide with oligosaccharides of specific composition and structure is essential for expression of the biological activity of the neurotoxin responsive Na+ channel

  6. EFFECT OF INFANT FORMULA SUPPLEMENTED WITH OLIGOSACCHARIDES ON STOOL CHARACTERISTICS OF INFANTS

    Institute of Scientific and Technical Information of China (English)

    TAO Ye-xuan; TANG Qing-ya; FENG Yi; CAI Wei

    2007-01-01

    Objective To determine whether addition of oligosaccharides to a regular infant formula can lead to changes in the colonic function in vivo, particularly the fecal characteristics. Methods One hundred and two health full term infants were randomly assigned to one of two experimental formula groups: oligosaccharide formula (OF) group or regular formula (RF) group. Fifty breast-fed infants served as a control group during the same period. During the 3 weeks' study, stool characteristics, including stooling frequency, stool consistency, pH and color, were recorded daily by parents. Results The mean fecal frequency of the infants in the OF group was significantly more than those of the RF group ( P < 0. 05 ). The stools of the RF group were significantly harder than those in the OF group( P < 0. 001 ). Although the mean stool pH score and stool color score of infants in the OF group were not significantly different from that of infants in the RF group, it was much closer to that of breast-fed infants. Conclusion The addition of oligosaccharides to a normal infant formula could lead to improvements in fecal characteristics.

  7. Major carbohydrate, polyol, and oligosaccharide profiles of agave syrup. Application of this data to authenticity analysis.

    Science.gov (United States)

    Willems, Jamie L; Low, Nicholas H

    2012-09-01

    Nineteen pure agave syrups representing the three major production regions and four processing facilities in Mexico were analyzed for their major carbohydrate, polyol, and oligosaccharide profiles, as well as their physicochemical properties (pH, °Brix, total acidity, percent total titratable acidity, and color). Additionally, the detection of intentional debasing of agave syrup with four commercial nutritive sweeteners (HFCS 55 and 90, DE 42 and sucrose) was afforded by oligosaccharide profiling employing both high performance anion exchange liquid chromatography with pulsed amperometric detection (HPAE-PAD) and capillary gas chromatography with flame ionization detection (CGC-FID). Results showed that the major carbohydrate and polyol in agave syrups were fructose and inositol with mean concentrations of 84.29% and 0.38%, respectively. Oligosaccharide profiling was extremely successful for adulteration detection with detection limits ranging from 0.5 to 2.0% for the aforementioned debasing agents. Also, all four of these possible adulterants could be detected within a single chromatographic analysis.

  8. Enzymatic Hydrolysis of Alginate to Produce Oligosaccharides by a New Purified Endo-Type Alginate Lyase

    Science.gov (United States)

    Zhu, Benwei; Chen, Meijuan; Yin, Heng; Du, Yuguang; Ning, Limin

    2016-01-01

    Enzymatic hydrolysis of sodium alginate to produce alginate oligosaccharides has drawn increasing attention due to its advantages of containing a wild reaction condition, excellent gel properties and specific products easy for purification. However, the efficient commercial enzyme tools are rarely available. A new alginate lyase with high activity (24,038 U/mg) has been purified from a newly isolated marine strain, Cellulophaga sp. NJ-1. The enzyme was most active at 50 °C and pH 8.0 and maintained stability at a broad pH range (6.0–10.0) and temperature below 40 °C. It had broad substrate specificity toward sodium alginate, heteropolymeric MG blocks (polyMG), homopolymeric M blocks (polyM) and homopolymeric G blocks (polyG), and possessed higher affinity toward polyG (15.63 mM) as well as polyMG (23.90 mM) than polyM (53.61 mM) and sodium alginate (27.21 mM). The TLC and MS spectroscopy analysis of degradation products suggested that it completely hydrolyzed sodium alginate into oligosaccharides of low degrees of polymerization (DPs). The excellent properties would make it a promising tool for full use of sodium alginate to produce oligosaccharides. PMID:27275826

  9. Presence of Inulin-Type Fructo-Oligosaccharides and Shift from Raffinose Family Oligosaccharide to Fructan Metabolism in Leaves of Boxtree (Buxus sempervirens).

    Science.gov (United States)

    Van den Ende, Wim; Coopman, Marlies; Vergauwen, Rudy; Van Laere, André

    2016-01-01

    Fructans are known to occur in 15% of flowering plants and their accumulation is often associated with stress responses. Typically, particular fructan types occur within particular plant families. The family of the Buxaceae, harboring Pachysandra terminalis, an accumulator of graminan- and levan-type fructans, also harbors boxtree (Buxus sempervirens), a cold and drought tolerant species. Surprisingly, boxtree leaves do not accumulate the expected graminan- and levan-type fructans, but small inulin fructo-oligosaccharides (FOS: 1-kestotriose and nystose) and raffinose family oligosaccharides (RFOs: raffinose and stachyose) instead. The seasonal variation in concentrations of glucose, fructose, sucrose, FOS and RFOs were followed. Raffinose and stachyose peaked during the winter months, while FOS peaked at a very narrow time-interval in spring, immediately preceded by a prominent sucrose accumulation. Sucrose may function as a reserve carbohydrate in winter and early spring leaves. The switch from RFO to fructan metabolism in spring strongly suggests that fructans and RFOs fulfill distinct roles in boxtree leaves. RFOs may play a key role in the cold acclimation of winter leaves while temporal fructan biosynthesis in spring might increase sink strength to sustain the formation of new shoots. PMID:26973663

  10. Presence of Inulin-Type Fructo-Oligosaccharides and Shift from Raffinose Family Oligosaccharide to Fructan Metabolism in Leaves of Boxtree (Buxus sempervirens).

    Science.gov (United States)

    Van den Ende, Wim; Coopman, Marlies; Vergauwen, Rudy; Van Laere, André

    2016-01-01

    Fructans are known to occur in 15% of flowering plants and their accumulation is often associated with stress responses. Typically, particular fructan types occur within particular plant families. The family of the Buxaceae, harboring Pachysandra terminalis, an accumulator of graminan- and levan-type fructans, also harbors boxtree (Buxus sempervirens), a cold and drought tolerant species. Surprisingly, boxtree leaves do not accumulate the expected graminan- and levan-type fructans, but small inulin fructo-oligosaccharides (FOS: 1-kestotriose and nystose) and raffinose family oligosaccharides (RFOs: raffinose and stachyose) instead. The seasonal variation in concentrations of glucose, fructose, sucrose, FOS and RFOs were followed. Raffinose and stachyose peaked during the winter months, while FOS peaked at a very narrow time-interval in spring, immediately preceded by a prominent sucrose accumulation. Sucrose may function as a reserve carbohydrate in winter and early spring leaves. The switch from RFO to fructan metabolism in spring strongly suggests that fructans and RFOs fulfill distinct roles in boxtree leaves. RFOs may play a key role in the cold acclimation of winter leaves while temporal fructan biosynthesis in spring might increase sink strength to sustain the formation of new shoots.

  11. B2O3/Al2O3 as a new, highly efficient and reusable heterogeneous catalyst for the selective synthesis of β-enamino ketones and esters under solvent-free conditions

    International Nuclear Information System (INIS)

    Boron oxide adsorbed on alumina (B2O3/Al2O3) has been found to be a new and highly efficient heterogeneous catalyst for the synthesis of β-enamino ketones and esters by the enamination of various primary and secondary amines with β-dicarbonyl compounds under solvent-free conditions. The important features of this methodology are broad substrate scope, high yield, no requirement of metal catalysts, high regio- and chemoselectivity and environmental friendliness. In addition, the catalyst could be recovered easily after the reactions and reused without evident loss of reactivity. (author)

  12. Sequence analysis of the pyruvylated galactan sulfate-derived oligosaccharides by negative-ion electrospray tandem mass spectrometry.

    Science.gov (United States)

    Li, Na; Mao, Wenjun; Liu, Xue; Wang, Shuyao; Xia, Zheng; Cao, Sujian; Li, Lin; Zhang, Qi; Liu, Shan

    2016-10-01

    Five sulfated oligosaccharide fragments, F1-F5, were prepared from a pyruvylated galactan sulfate from the green alga Codium divaricatum, by partial depolymerization using mild acid hydrolysis and purification with gel-permeation chromatography. Negative-ion electrospray tandem mass spectrometry with collision-induced dissociation (ES-CID-MS/MS) is attempted for sequence determination of the sulfated oligosaccharides. The sequence of F1 with homogeneous disaccharide composition was first characterized to be Galp-(4SO4)-(1 → 3)-Galp by detailed nuclear magnetic resonance spectroscopic analyses. The fragmentation pattern of F1 in the product ion spectra was established on the basis of negative-ion ES-CID MS/MS, which was then applied to sequence analysis of other sulfated oligosaccharides. The sequences of F2 and F3 were deduced to be Galp-(4SO4)-(1 → 3)-Galp-(1 → 3)-Galp-(1 → 3)-Galp and 3,4-O-(1-carboxyethylidene)-Galp-(6SO4)-(1 → 3)-Galp, respectively. The sequences of major fragments in F4 and F5 were also deduced. The investigation demonstrated that negative-ion ES-CID-MS/MS was an efficient method for the sequence analysis of the pyruvylated galactan sulfate-derived oligosaccharides which revealed the patterns of substitution and glycosidic linkages. The pyruvylated galactan sulfate-derived oligosaccharides were novel sulfated oligosaccharides different from other algal polysaccharide-derived oligosaccharides. PMID:27471831

  13. Chromatographic profiles of blood plasma free oligosaccharides in patients with cardiovascular disease

    Directory of Open Access Journals (Sweden)

    I. U. Pismenetskaya

    2015-03-01

    Full Text Available Free oligosaccharides (FOS are unbound structural analogs of glycans of glycoconjugates. There are several sources of them inside the cell: 1 multistep pathways of N-glycosylation, 2 the cell quality control and endoplastic reticulum-associated degradation of mis-glycosylated and/or misfolded glycoproteins, 3 lysosomal degradation of mature glycoconjugates. Some of these FOS are the earliest indicators of potential glycosylation alterations that would be revealed in the course of the cell quality control and the endoplastic reticulum-associated degradation. Ischemia and hypertension cause stress of intracellular organelles leading to disruption of their functions. The main objective of the work was the characterization of free oligosaccharides (FOS in plasma obtained from patients with cardiovascular diseases compared to those from healthy subjects to evaluate the potential of these compounds for diagnostics. Chromatographic profiles of FOS composed of 4–12 monosaccharides were obtained and analyzed for quantitative and qualitative differences between the samples. After plasma deproteinization and FOS purification the oligosaccharides were labelled with anthranilic acid (2-AA, separated into the neutral and charged with QAE Sephadex (Q25-120 chromatography and analysed using high-performance liquid chromatography (HPLC. Glucose unit values were determined following comparison with a 2-AA-labelled glucose oligomer ladder derived from a partial hydrolysate of dextran as an external standard. The data were collected and processed using Empower software. The charged FOS were digested with the sialidase from Arthrobacter ureafaciens. 2-AA – labelled free oligosaccharides from transferrin were used as an external standard for the structure decoding. The profiles obtained were compared with intracellular free oligosaccharides of known structures and with the glycan structures and their descriptions in the databases GlycoBase and EUROCarbDB. These

  14. Synthesis of a Sulfonated Two-Dimensional Covalent Organic Framework as an Efficient Solid Acid Catalyst for Biobased Chemical Conversion.

    Science.gov (United States)

    Peng, Yongwu; Hu, Zhigang; Gao, Yongjun; Yuan, Daqiang; Kang, Zixi; Qian, Yuhong; Yan, Ning; Zhao, Dan

    2015-10-12

    Because of limited framework stability tolerance, de novo synthesis of sulfonated covalent organic frameworks (COFs) remains challenging and unexplored. Herein, a sulfonated two-dimensional crystalline COF, termed TFP-DABA, was synthesized directly from 1,3,5-triformylphloroglucinol and 2,5-diaminobenzenesulfonic acid through a previously reported Schiff base condensation reaction, followed by irreversible enol-to-keto tautomerization, which strengthened its structural stability. TFP-DABA is a highly efficient solid acid catalyst for fructose conversion with remarkable yields (97 % for 5-hydroxymethylfurfural and 65 % for 2,5-diformylfuran), good chemoselectivity, and good recyclability. The present study sheds light on the de novo synthesis of sulfonated COFs as novel solid acid catalysts for biobased chemical conversion.

  15. Synthesis of a Sulfonated Two-Dimensional Covalent Organic Framework as an Efficient Solid Acid Catalyst for Biobased Chemical Conversion.

    Science.gov (United States)

    Peng, Yongwu; Hu, Zhigang; Gao, Yongjun; Yuan, Daqiang; Kang, Zixi; Qian, Yuhong; Yan, Ning; Zhao, Dan

    2015-10-12

    Because of limited framework stability tolerance, de novo synthesis of sulfonated covalent organic frameworks (COFs) remains challenging and unexplored. Herein, a sulfonated two-dimensional crystalline COF, termed TFP-DABA, was synthesized directly from 1,3,5-triformylphloroglucinol and 2,5-diaminobenzenesulfonic acid through a previously reported Schiff base condensation reaction, followed by irreversible enol-to-keto tautomerization, which strengthened its structural stability. TFP-DABA is a highly efficient solid acid catalyst for fructose conversion with remarkable yields (97 % for 5-hydroxymethylfurfural and 65 % for 2,5-diformylfuran), good chemoselectivity, and good recyclability. The present study sheds light on the de novo synthesis of sulfonated COFs as novel solid acid catalysts for biobased chemical conversion. PMID:26448524

  16. Comprehensive peptidomic and glycomic evaluation reveals that sweet whey permeate from colostrum is a source of milk protein-derived peptides and oligosaccharides

    Science.gov (United States)

    Dallas, David C.; Weinborn, Valerie; de Moura Bell, Juliana M.L.N.; Wang, Meng; Parker, Evan A.; Guerrero, Andres; Hettinga, Kasper A.; Lebrilla, Carlito B.; German, J. Bruce; Barile, Daniela

    2014-01-01

    Whey permeate is a co-product obtained when cheese whey is passed through an ultrafiltration membrane to concentrate whey proteins. Whey proteins are retained by the membrane, whereas the low-molecular weight compounds such as lactose, salts, oligosaccharides and peptides pass through the membrane yielding whey permeate. Research shows that bovine milk from healthy cows contains hundreds of naturally occurring peptides – many of which are homologous with known antimicrobial and immunomodulatory peptides – and nearly 50 oligosaccharide compositions (not including structural isomers). As these endogenous peptides and oligosaccharides have low-molecular weight and whey permeate is currently an under-utilized product stream of the dairy industry, we hypothesized that whey permeate may serve as an inexpensive source of naturally occurring functional peptides and oligosaccharides. Laboratory fractionation of endogenous peptides and oligosaccharides from bovine colostrum sweet whey was expanded to pilot-scale. The membrane fractionation methodology used was similar to the methods commonly used industrially to produce whey protein concentrate and whey permeate. Pilot-scale fractionation was compared to laboratory-scale fractionation with regard to the identified peptides and oligosaccharide compositions. Results were interpreted on the basis of whether industrial whey permeate could eventually serve as a source of functional peptides and oligosaccharides. The majority (96%) of peptide sequences and the majority (96%) of oligosaccharide compositions found in the laboratory-scale process were mirrored in the pilot-scale process. Moreover, the pilot-scale process recovered an additional 33 peptides and 1 oligosaccharide not identified from the laboratory-scale extraction. Both laboratory- and pilot-scale processes yielded peptides deriving primarily from the protein β-casein. The similarity of the laboratory-and pilot-scale's resulting peptide and oligosaccharide

  17. Oligosaccharide substrate preferences of human extracellular sulfatase Sulf2 using liquid chromatography-mass spectrometry based glycomics approaches.

    Directory of Open Access Journals (Sweden)

    Yu Huang

    Full Text Available Sulfs are extracellular endosulfatases that selectively remove the 6-O-sulfate groups from cell surface heparan sulfate (HS chain. By altering the sulfation at these particular sites, Sulfs function to remodel HS chains. As a result of the remodeling activity, HSulf2 regulates a multitude of cell-signaling events that depend on interactions between proteins and HS. Previous efforts to characterize the substrate specificity of human Sulfs (HSulfs focused on the analysis of HS disaccharides and synthetic repeating units. In this study, we characterized the substrate preferences of human HSulf2 using HS oligosaccharides with various lengths and sulfation degrees from several naturally occurring HS sources by applying liquid chromatography mass spectrometry based glycomics methods. The results showed that HSulf2 preferentially digests highly sulfated HS oligosaccharides with zero acetyl groups and this preference is length dependent. In terms of length of oligosaccharides, HSulf2 digestion induced more sulfation decrease on DP6 (DP: degree of polymerization compared to DP2, DP4 and DP8. In addition, the HSulf2 preferentially digests the oligosaccharide domain located at the non-reducing end (NRE of the HS and heparin chain. In addition, the HSulf2 digestion products were altered only for specific isomers. HSulf2 treated NRE oligosaccharides also showed greater decrease in cell proliferation than those from internal domains of the HS chain. After further chromatographic separation, we identified the three most preferred unsaturated hexasaccharide for HSulf2.

  18. Improved liquid chromatography-MS/MS of heparan sulfate oligosaccharides via chip-based pulsed makeup flow.

    Science.gov (United States)

    Huang, Yu; Shi, Xiaofeng; Yu, Xiang; Leymarie, Nancy; Staples, Gregory O; Yin, Hongfeng; Killeen, Kevin; Zaia, Joseph

    2011-11-01

    Microfluidic chip-based hydrophilic interaction chromatography (HILIC) is a useful separation system for liquid chromatography-mass spectrometry (LC-MS) in compositional profiling of heparan sulfate (HS) oligosaccharides; however, ions observed using HILIC LC-MS are low in charge. Tandem MS of HS oligosaccharide ions with low charge results in undesirable losses of SO(3) from precursor ions during collision induced dissociation. One solution is to add metal cations to stabilize sulfate groups. Another is to add a nonvolatile, polar compound such as sulfolane, a molecule known to supercharge proteins, to produce a similar effect for oligosaccharides. We demonstrate use of a novel pulsed makeup flow (MUF) HPLC-chip. The chip enables controlled application of additives during specified chromatographic time windows and thus minimizes the extent to which nonvolatile additives build up in the ion source. The pulsed MUF system was applied to LC-MS/MS of HS oligosaccharides. Metal cations and sulfolane were tested as additives. The most promising results were obtained for sulfolane, for which supercharging of the oligosaccharide ions increased their signal strengths relative to controls. Tandem MS of these supercharged precursor ions showed decreased abundances of product ions from sulfate losses yet more abundant product ions from backbone cleavages.

  19. Exposure of Bifidobacterium longum subsp. infantis to Milk Oligosaccharides Increases Adhesion to Epithelial Cells and Induces a Substantial Transcriptional Response.

    Directory of Open Access Journals (Sweden)

    Devon W Kavanaugh

    Full Text Available In this study, we tested the hypothesis that milk oligosaccharides may contribute not only to selective growth of bifidobacteria, but also to their specific adhesive ability. Human milk oligosaccharides (3'sialyllactose and 6'sialyllactose and a commercial prebiotic (Beneo Orafti P95; oligofructose were assayed for their ability to promote adhesion of Bifidobacterium longum subsp. infantis ATCC 15697 to HT-29 and Caco-2 human intestinal cells. Treatment with the commercial prebiotic or 3'sialyllactose did not enhance adhesion. However, treatment with 6'sialyllactose resulted in increased adhesion (4.7 fold, while treatment with a mixture of 3'- and 6'-sialyllactose substantially increased adhesion (9.8 fold to HT-29 intestinal cells. Microarray analyses were subsequently employed to investigate the transcriptional response of B. longum subsp. infantis to the different oligosaccharide treatments. This data correlated strongly with the observed changes in adhesion to HT-29 cells. The combination of 3'- and 6'-sialyllactose resulted in the greatest response at the genetic level (both in diversity and magnitude followed by 6'sialyllactose, and 3'sialyllactose alone. The microarray data was further validated by means of real-time PCR. The current findings suggest that the increased adherence phenotype of Bifidobacterium longum subsp. infantis resulting from exposure to milk oligosaccharides is multi-faceted, involving transcription factors, chaperone proteins, adhesion-related proteins, and a glycoside hydrolase. This study gives additional insight into the role of milk oligosaccharides within the human intestine and the molecular mechanisms underpinning host-microbe interactions.

  20. 功能性低聚糖的开发应用前景%The developing prospects of oligosaccharides

    Institute of Scientific and Technical Information of China (English)

    邱伟芬

    2001-01-01

    This paper makes a brief introduction of the structures of several important oligosaccharides.The important functions of oligosaccharides such as growth factor for bifidobacteria, low calorie and no dental caries are studied.Furthermore,the development and application of oligosaccharides are discussed and predicted.Oligosaccharides will be widely used as food ingredients in functional foods.R& D of oligosaccharides will have broad prospects.%简要介绍了几种主要低聚糖的结构,讨论了功能性低聚糖的双歧因子、低热量、抗龋齿等主要功能,对低聚糖的开发应用作了探讨及展望,提出低聚糖将作为一种功能性食品基料在功能性食品中得到广泛应用,开发应用功能性低聚糖具有广阔的前景。

  1. Valorization of Cheese and Tofu Whey through Enzymatic Synthesis of Lactosucrose

    OpenAIRE

    Corzo-Martinez, Marta; Luscher, Alice; de las Rivas, Blanca; Muñoz, Rosario; Moreno, F. Javier

    2015-01-01

    This work deals with the development of a new bioprocess for the efficient synthesis of lactosucrose, a potential prebiotic oligosaccharide with a high value-added, from two important and inexpensive agro-industrial by-products such as tofu whey and cheese whey permeate. The bioconversion is driven by the ability of the enzyme levansucrase SacB from Bacillus subtilis CECT 39 to transfructosylate lactose contained in the cheese whey permeate by using not only sucrose but also raffinose and sta...

  2. Fermentation properties and potential prebiotic activity of Bimuno® galacto-oligosaccharide (65 % galacto-oligosaccharide content) on in vitro gut microbiota parameters.

    Science.gov (United States)

    Grimaldi, Roberta; Swann, Jonathan R; Vulevic, Jelena; Gibson, Glenn R; Costabile, Adele

    2016-08-01

    Prebiotic oligosaccharides have the ability to generate important changes in the gut microbiota composition that may confer health benefits to the host. Reducing the impurities in prebiotic mixtures could expand their applications in food industries and improve their selectivity and prebiotic effect on the potential beneficial bacteria such as bifidobacteria and lactobacilli. This study aimed to determine the in vitro potential fermentation properties of a 65 % galacto-oligosaccharide (GOS) content Bimuno® GOS (B-GOS) on gut microbiota composition and their metabolites. Fermentation of 65 % B-GOS was compared with 52 % B-GOS in pH- and volume-controlled dose-response anaerobic batch culture experiments. In total, three different doses (1, 0·5 and 0·33 g equivalent to 0·1, 0·05 and 0·033 g/l) were tested. Changes in the gut microbiota during a time course were identified by fluorescence in situ hybridisation, whereas small molecular weight metabolomics profiles and SCFA were determined by 1H-NMR analysis and GC, respectively. The 65 % B-GOS showed positive modulation of the microbiota composition during the first 8 h of fermentation with all doses. Administration of the specific doses of B-GOS induced a significant increase in acetate as the major SCFA synthesised compared with propionate and butyrate concentrations, but there were no significant differences between substrates. The 65 % B-GOS in syrup format seems to have, in all the analysis, an efficient prebiotic effect. However, the applicability of such changes remains to be shown in an in vivo trial. PMID:27267934

  3. Enzymes as Green Catalysts for Precision Macromolecular Synthesis.

    Science.gov (United States)

    Shoda, Shin-ichiro; Uyama, Hiroshi; Kadokawa, Jun-ichi; Kimura, Shunsaku; Kobayashi, Shiro

    2016-02-24

    The present article comprehensively reviews the macromolecular synthesis using enzymes as catalysts. Among the six main classes of enzymes, the three classes, oxidoreductases, transferases, and hydrolases, have been employed as catalysts for the in vitro macromolecular synthesis and modification reactions. Appropriate design of reaction including monomer and enzyme catalyst produces macromolecules with precisely controlled structure, similarly as in vivo enzymatic reactions. The reaction controls the product structure with respect to substrate selectivity, chemo-selectivity, regio-selectivity, stereoselectivity, and choro-selectivity. Oxidoreductases catalyze various oxidation polymerizations of aromatic compounds as well as vinyl polymerizations. Transferases are effective catalysts for producing polysaccharide having a variety of structure and polyesters. Hydrolases catalyzing the bond-cleaving of macromolecules in vivo, catalyze the reverse reaction for bond forming in vitro to give various polysaccharides and functionalized polyesters. The enzymatic polymerizations allowed the first in vitro synthesis of natural polysaccharides having complicated structures like cellulose, amylose, xylan, chitin, hyaluronan, and chondroitin. These polymerizations are "green" with several respects; nontoxicity of enzyme, high catalyst efficiency, selective reactions under mild conditions using green solvents and renewable starting materials, and producing minimal byproducts. Thus, the enzymatic polymerization is desirable for the environment and contributes to "green polymer chemistry" for maintaining sustainable society.

  4. Regulatory T Cell Depletion Abolishes the Protective Effect of Dietary Galacto-Oligosaccharides on Eosinophilic Airway Inflammation in House Dust Mite-Induced Asthma in Mice

    NARCIS (Netherlands)

    Verheijden, Kim At; Braber, Saskia; Leusink-Muis, Thea; Thijssen, Suzan; Boon, Louis; Kraneveld, Aletta D; Garssen, Johan; Folkerts, Gert; Willemsen, Linette Em

    2016-01-01

    BACKGROUND: In a murine model for house dust mite (HDM)-induced asthma, dietary galacto-oligosaccharides have been shown to suppress allergic symptoms. Previously, CD25(+) regulatory T cells (Tregs) induced by nondigestible oligosaccharides were found to protect against allergy development. OBJECTIV

  5. 2,6 Sialylation associated with increased 1,6-branched -oligosaccharides influences cellular adhesion and invasion

    Indian Academy of Sciences (India)

    Amit Ranjan; Rajiv D Kalraiya

    2013-12-01

    Expression of 1,6-branched N-linked oligosaccharides have a definite association with invasion and metastasis of cancer cells. However, the mechanism by which these oligosaccharides regulate these processes is not well understood. Invasive variants of B16 murine melanoma, B16F10 (parent) and B16BL6 (highly invasive variant) cell lines have been used for these studies. We demonstrate that substitution of 2,6-linked sialic acids on multiantennary structures formed as a result of 1,6-branching modulate cellular adhesion on both extracellular matrix (ECM) and basement membrane (BM) components. Removal of 2,6 sialic acids either by enzymatic desialylation or by stably down-regulating the ST6Gal-I (enzyme that catalyses the addition of 2,6-linked sialic acids on N-linked oligosaccharides) by lentiviral driven shRNA decreased the adhesion on both ECM and BM components and invasion through reconstituted BM matrigel.

  6. The Effect of Oligosaccharides in Sports Drink on Exercise Performance and Endurance Time of Athletes

    Directory of Open Access Journals (Sweden)

    Mi Dong

    2015-05-01

    Full Text Available This study aims to investigate the effect of oligosaccharides in sports drink on high-intensity exercise capacity in athletes. In our research, sixteen healthy male students of Institute of Physical Education were randomly divided into Oligosaccharide Replenishment (OR group (n = 8 and control group (n = 8. Their max oxygen uptake were measured by 2900 cardiorespiratory function meter, then they all participated in a cycling test at the intensity of 80% oxygen consumption max until fatigue. The results showed that blood glucose (mmol/L in the OR group was higher than that in the control group during exercise, the difference between the two groups was more significant along with time (5.29±1.07-6.46±0.78 and 4.71±0.84-5.36±0.80, p<0.05. 30 min after the exercise, the change of blood lactate in the OR group was higher than that in the control group both during (6.69±1.57-7.39±1.19 and after (6.18±1.28-5.19±1.14 the exercise (p<0.05. Cycling time [(47±12 min] and work load [(174.9±3.6 kJ] in the OR group were significantly higher than those in the control group (p<0.05. From these results, we can see that oligosaccharide-replenishing is good for keeping blood glucose level for a long time in high-intensity exercise and prolong the time of high-intense exercise.

  7. Molecular diversity of the genetic loci responsible for lipopolysaccharide core oligosaccharide assembly within the genus Salmonella.

    Science.gov (United States)

    Kaniuk, Natalia A; Monteiro, Mario A; Parker, Craig T; Whitfield, Chris

    2002-12-01

    The waa locus on the chromosome of Salmonella enterica encodes enzymes involved in the assembly of the core oligosaccharide region of the lipopolysaccharide (LPS) molecule. To date, there are two known core structures in Salmonella, represented by serovars Typhimurium (subspecies I) and Arizonae (subspecies IIIA). The waa locus for serovar Typhimurium has been characterized. Here, the corresponding locus from serovar Arizonae is described, and the molecular basis for the distinctive structures is established. Eleven of the 13 open reading frames (ORFs) are shared by the two loci and encode conserved proteins of known function. Two polymorphic regions distinguish the waa loci. One involves the waaK gene, the product of which adds a terminal alpha-1,2-linked N-acetylglucosamine residue that characterizes the serovar Typhimurium core oligosaccharide. There is an extensive internal deletion within waaK of serovar Arizonae. The serovar Arizonae locus contains a novel ORF (waaH) between the waaB and waaP genes. Structural analyses and in vitro glycosyltransferase assays identified WaaH as the UDP-glucose:(glucosyl) LPS alpha-1,2-glucosyltransferase responsible for the addition of the characteristic terminal glucose residue found in serovar Arizonae. Isolates comprising the Salmonella Reference Collections, SARC (representing the eight subspecies of S. enterica) and SARB (representing subspecies I), were examined to assess the distribution of the waa locus polymorphic regions in natural populations. These comparative studies identified additional waa locus polymorphisms, shedding light on the genetic basis for diversity in the LPS core oligosaccharides of Salmonella isolates and identifying potential sources of further novel LPS structures.

  8. Structural characterization of the N-linked oligosaccharides from tomato fruit.

    Science.gov (United States)

    Zeleny, R; Altmann, F; Praznik, W

    1999-05-01

    The primary structures of the N-linked oligosaccharides from tomato fruit (Lycopersicon esculentum) have been elucidated. For the isolation of the protein fraction, two procedures were employed alternatively: a low temperature acetone powder method and ammonium sulfate precipitation of the tomato extract. After peptic digestion, the glycopeptides were purified by cation-exchange chromatography; the oligosaccharides were released by N-glycosidase A and fluorescently labelled with 2-aminopyridine. Structural characterization was accomplished by means of two-dimensional HPLC in combination with exoglycosidase digestions and MALDI-TOF mass spectrometry. Two varieties as well as two stages of ripening were investigated. In all the samples, the same sixteen N-glycosidic structures were detected; the two most abundant glycans showed identical properties to those of the major N-linked oligosaccharides of horseradish peroxidase and pineapple stem bromelain, respectively and accounted for about 65-78% of the total glycan amount; oligomannosidic glycans occurred only in small quantities (3-9%). The majority of the N-glycans were beta 1,2-xylosylated and carried an alpha 1,3-fucose residue linked to the terminal N-acetylglucosamine. This structural element contributes to cross-reactions among non-related glycoproteins and has been shown to be an IgE-reactive determinant (Tretter, Altmann, Kubelka, März, & Becker, 1993). The presented study gives a possible structural explanation for reported immunological cross-reactivities between tomato and grass pollen extracts due to carbohydrate IgE epitopes (Petersen, Vieths, Aulepp, Schlaak, & Becker, 1996), thereby demonstrating the importance of the structural characterization of plant N-glycans for a more reliable interpretation of immunological data. PMID:10365448

  9. Purification and characterization of a xyloglucan oligosaccharide-specific xylosidase from pea seedlings

    Energy Technology Data Exchange (ETDEWEB)

    O' Neill, R.A.; Albersheim, P.; Darvill, A.G. (Univ. of Georgia, Athens (United States))

    1989-12-05

    An {alpha}-xylosidase that acts on oligosaccharide fragments of xyloglucan, a plant cell wall polysaccharide, was purified from pea (Pisum sativum) epicotyls that had been treated with an auxin analog. The enzyme had an apparent molecular mass of 85,000 Da according to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 79,000 Da according to gel-permeation chromatography under nondenaturing conditions. The purified xylosidase consisted of a series of closely related, enzymatically active proteins with isoelectric points ranging from about pH 7.35 to 7.7; the xylosidases were separated by chromatofocusing. The pH optimum of the mixed xylosidase was 4.9-5.1. The substrate specificity of the xylosidase mixture was determined by purification and structural characterization of the products of treating xyloglucan-oligosaccharide substrates with the enzyme. Characterization of the substrates and products included elution volume from a gel-permeation column, glycosyl residue and glycosyl linkage composition analyses, fast atom bombardment-mass spectrometry, and {sup 1}H NMR spectroscopy. The enzyme specifically cleaved only one of the {alpha}-xylosidic linkages of xyloglucan-oligosaccharide substrates, the one attached to a 6-linked glucosyl residue, not those attached to the 4,6-linked glucosyl residues. The enzyme was unable to cleave the xylosidic linkage of p-nitrophenyl-{alpha}-D-xylopyranoside or the {alpha}-xylosidic linkage to C-6 of glucose in the disaccharide isoprimeverose. The enzyme was also unable to release measurable amounts of xylose from large xyloglucan polymers.

  10. Subtilisin-catalyzed esterification of di- and oligosaccharides containing a d-fructose moiety

    Energy Technology Data Exchange (ETDEWEB)

    Riva, S.; Nonini, M.; Ottolina, G. [Istituto di Biocatalisi e Riconoscimento Molecolare, C.N.R., via Mario Bianco 9, I-20131 Milan (Italy); Danieli, B. [Dipartimento di Chimica Organica e Industriale, Centro C.N.R.. di Studio sulle Sostanze Organiche Naturali, via Venezian 21, I-20133 Milan (Italy)

    1998-12-31

    Several di- and oligosaccharides containing a d-fructose moiety have been acylated by protease subtilisin in anhydrous dimethylformamide in the presence of the activated ester trifluoroethyl butanoate. Under the reaction conditions used, all the substrates were converted into the corresponding monobutanoates in ca. 50% isolated yields. Structural determination of the products by {sup 13}C NMR indicated a strong preference of subtilisin towards the regioselective esterification of the primary hydroxyls of the fructose moiety and, specifically, of the C-1 OH, as already observed with sucrose. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  11. Subtilisin-catalyzed esterification of di- and oligosaccharides containing a d-fructose moiety

    International Nuclear Information System (INIS)

    Several di- and oligosaccharides containing a d-fructose moiety have been acylated by protease subtilisin in anhydrous dimethylformamide in the presence of the activated ester trifluoroethyl butanoate. Under the reaction conditions used, all the substrates were converted into the corresponding monobutanoates in ca. 50% isolated yields. Structural determination of the products by 13C NMR indicated a strong preference of subtilisin towards the regioselective esterification of the primary hydroxyls of the fructose moiety and, specifically, of the C-1 OH, as already observed with sucrose. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  12. Structural and interaction analysis of helical heparin oligosaccharides with the fragment molecular orbital method

    Science.gov (United States)

    Sawada, Toshihiko; Fedorov, Dmitri G.; Kitaura, Kazuo

    The fragment molecular orbital method (FMO) was applied to the geometry optimization of several heparin oligosaccharides at the RHF/6-31(+)G(d) level combined with the polarizable continuum model (PCM). For comparison, GLYCAM force field optimization in explicit solvent was also conducted. Good accuracy of FMO was demonstrated in comparison to ab initio at the MP2/PCM level. The interaction analysis was conducted using the pair interaction energy decomposition analysis (PIEDA), and the role of hydrogen bonding and solvent was elucidated in the helix formation of heparin in solution. Content:text/plain; charset="UTF-8"

  13. Prebiotic Oligosaccharides: Comparative Evaluation Using In Vitro Cultures of Infants' Fecal Microbiomes

    OpenAIRE

    Stiverson, J.; Williams, T; Chen, J; Adams, S.; Hustead, D.; Price, P.; Guerrieri, J.; Deacon, J; Yu, Z.

    2014-01-01

    The objective of this study was to systematically assess the bifidogenic effect of three commonly used prebiotic products using in vitro cultures of infant fecal samples. Fresh stool samples collected from six term infants, each exclusively fed human milk (n = 3) or infant formula (n = 3), at 28 days of age were used as inocula. The following prebiotic products were added at concentrations applicable to infant formula: Vivinal GOS 15 (containing 28.5% galacto-oligosaccharide [GOS]) at 7.2 g/l...

  14. Xylan oligosaccharides and cellobiohydrolase I (TrCeI7A) interaction and effect on activity

    DEFF Research Database (Denmark)

    Baumann, Martin Johannes; Borch, Kim; Westh, Peter

    2011-01-01

    significant research interest because of the role of the CBHs in the conversion of biomass to fermentable sugars. However, the CHBs are notoriously slow and susceptible to inhibition, which presents a challenge for the commercial utilisation of biomass. The xylans and xylan fragments that are also present...... in the biomass have been suggested repeatedly as one cause of the reduced activity of CHBs. Yet, the extent and mechanisms of this inhibition remain poorly elucidated. Therefore, we studied xylan oligosaccharides (XOSs) of variable lengths with respect to their binding and inhibition of both TrCel7A...

  15. Rice Bran Feruloylated Oligosaccharides Activate Dendritic Cells via Toll-Like Receptor 2 and 4 Signaling

    OpenAIRE

    Chi Chen Lin; Hua Han Chen; Yu Kuo Chen; Hung Chia Chang; Ping Yi Lin; I-Hong Pan; Der-Yuan Chen; Chuan Mu Chen; Su Yi Lin

    2014-01-01

    This work presents the effects of feruloylated oligosaccharides (FOs) of rice bran on murine bone marrow-derived dendritic cells (BMDCs) and the potential pathway through which the effects are mediated. We found that FOs induced phenotypic maturation of DCs, as shown by the increased expression of CD40, CD80/CD86 and MHC-I/II molecules. FOs efficiently induced maturation of DCs generated from C3H/HeN or C57BL/6 mice with normal toll-like receptor 4 (TLR-4) or TLR-2 but not DCs from mice with ...

  16. New Trends and Technological Challenges in the Industrial Production and Purification of Fructo-oligosaccharides.

    Science.gov (United States)

    Nobre, Clarisse; Teixeira, José A; Rodrigues, Lígia R

    2015-01-01

    An increased commercial interest in fructo-oligosaccharides (FOS) has emerged in the last decade due to their prebiotic activity. At large scale, the FOS are produced by microbial enzymes from sucrose. A mixture of FOS and other saccharides is obtained in this process. The presence of such saccharides reduces the prebiotic, caloric, and cariogenic value of the final product. Therefore, many efforts have been conducted to obtain a product with increased FOS purity. This review comprises the most important technological and physicochemical aspects including FOS production and recovery processes; safety, dose and health claims concerning its intake; and commercially available FOS. PMID:24915327

  17. Induction of Volatile Organic Compounds of Lycopersicon esculentum Mill. and Its Resistance to Botrytis cinerea Pers. by Burdock Oligosaccharide

    Institute of Scientific and Technical Information of China (English)

    Pei-Qing He; Li Tian; Kao-Shan Chen; Lin-Hua Hao; Guang-You Li

    2006-01-01

    In the present study, we investigated the induction of volatile organic compounds (VOCs) of Lycopersicon esculentum Mill. and its resistance to Botrytis cinerea Pers. by burdock oligosaccharide. The disease severity of L. esculentum was evaluated 48 h after treatment with 0.6% burdock oligosaccharide, followed by inoculation with a spore suspension of B. cinerea. The formation of O()2, the activity of lipoxygenases (LOX), peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD), and the quantity and quality of changes in VOCs were determined a period of time after treatment with 0.6% burdock oligosaccharide. The results demonstrated that the disease index in treated plants was decreased by 42.5% compared with control 96 h after inoculation. The production of O()2 reached a maximum 6 h after treatment (1.36-fold compared with control). There was an increase in LOX, POD, CAT and SOD activity in response to burdock oligosaccharide treatment and the enzymes showed different trends in the time-course of induction. At 120 h after treatment,(E)-2-hexenal was increased by 92% compared with control, whereas methyl salicylate showed a gradual increase with induction period. Previous results had demonstrated that chitosan elicitor enhanced the production VOCs of L. esculentum and decreased plant susceptibility towards B. cinerea. Together, these findings suggest that increasing the production of VOCs in response to burrdock oligosaccharide may be an important mechanism for L. esculentumin its defense against pathogens. In addition, burrdock oligosaccharide may act as a potent elicitor of resistance to disease in L. esculentum.

  18. Stable Alkynyl Glycosyl Carbonates: Catalytic Anomeric Activation and Synthesis of a Tridecasaccharide Reminiscent of Mycobacterium tuberculosis Cell Wall Lipoarabinomannan.

    Science.gov (United States)

    Mishra, Bijoyananda; Neralkar, Mahesh; Hotha, Srinivas

    2016-06-27

    Oligosaccharide synthesis is still a challenging task despite the advent of modern glycosidation techniques. Herein, alkynyl glycosyl carbonates are shown to be stable glycosyl donors that can be activated catalytically by gold and silver salts at 25 °C in just 15 min to produce glycosides in excellent yields. Benzoyl glycosyl carbonate donors are solid compounds with a long shelf life. This operationally simple protocol was found to be highly efficient for the synthesis of nucleosides, amino acids, and phenolic and azido glycoconjugates. Repeated use of the carbonate glycosidation method enabled the highly convergent synthesis of tridecaarabinomannan in a rapid manner. PMID:26879797

  19. Microwave Assisted Convenient One-Pot Synthesis of Coumarin Derivatives via Pechmann Condensation Catalyzed by FeF3 under Solvent-Free Conditions and Antimicrobial Activities of the Products

    Directory of Open Access Journals (Sweden)

    Vahid Vahabi

    2014-08-01

    Full Text Available A rapid and efficient solvent-free one-pot synthesis of coumarin derivatives by Pechmann condensation reactions of phenols with ethyl acetoacetate using FeF3 as a catalyst under microwave irradiation is described. This one-pot synthesis on a solid inorganic support provides the products in good yields. The newly synthesized compounds were systematically characterized by IR, 1H-NMR, 13C-NMR, MS and elemental CHN analyses. The proposed solvent-free microwave irradiation method using the environmentally friendly catalyst FeF3 offers the unique advantages of high yields, shorter reaction times, easy and quick isolation of the products, excellent chemoselectivity, and a one-pot, green synthesis. The products were screened for antimicrobial activity, and the results showed that the compounds reacted against all the tested bacteria.

  20. Exogenous application of pectin-derived oligosaccharides to grape berries modifies anthocyanin accumulation, composition and gene expression.

    Science.gov (United States)

    Villegas, Daniel; Handford, Michael; Alcalde, José Antonio; Perez-Donoso, Alonso

    2016-07-01

    Anthocyanins are secondary metabolites synthesized in grape berry skins via the phenylpropanoid pathway, with functions ranging from skin coloration to protection against pathogens or UV light. Accumulation of these compounds is highly variable depending on genetics, environmental factors and viticultural practices. Besides their biological functions, anthocyanins improve wine quality, as a high anthocyanin content in berries has a positive impact on the color, total phenolic concentration and, ultimately, the price of wine. The present work studies the effect of the pre-veraison application of pectin derived oligosaccharides (PDO) on the synthesis and accumulation of these compounds, and associates the changes observed with the expression of key genes in the phenylpropanoid pathways. To this end, pre-veraison Cabernet Sauvignon bunches were treated with PDO to subsequently determine total anthocyanin content, the anthocyanin profile (by HPLC-DAD) and gene expression (by qRT-PCR), using Ethrel and water treatments for comparison. The results show that PDO were as efficient as Ethrel in generating a significant rise in total anthocyanin content at 30 days after treatment (dat), compared with water treatments (1.32, 1.48 and 1.02 mg e.Mv-3G/g FW respectively) without any undesirable effect on berry size, soluble solids, tartaric acid concentration or pH. In addition, a significant alteration in the anthocyanin profile was observed. Specifically, a significant increase in the relative concentration of malvidin was observed for both PDO and Ethrel treatments, compared with water controls (52.8; 55.0 and 48.3%, respectively), with a significant rise in tri-hydroxylated forms and a fall in di-hydroxylated anthocyanins. The results of gene expression analyses suggest that the increment in total anthocyanin content is related to a short term increase in phenylalanine ammonia-lyase (PAL) expression, mediated by a decrease in MYB4A expression. A longer term increase in UDP

  1. Supercritical water treatment for cello-oligosaccharide production from microcrystalline cellulose.

    Science.gov (United States)

    Tolonen, Lasse K; Juvonen, Minna; Niemelä, Klaus; Mikkelson, Atte; Tenkanen, Maija; Sixta, Herbert

    2015-01-12

    Microcrystalline cellulose was treated in supercritical water at 380 °C and at a pressure of 250 bar for 0.2, 0.4, and 0.6s. The yield of the ambient-water-insoluble precipitate and its average molar mass decreased with an extended treatment time. The highest yield of 42 wt% for DP2-9 cello-oligosaccharides was achieved after the 0.4s treatment. The reaction products included also 11 wt% ambient-water-insoluble precipitate with a DP(w) of 16, and 6.1 wt% monomeric sugars, and 37 wt% unidentified degradation products. Oligo- and monosaccharide-derived dehydration and retro-aldol fragmentation products were analyzed via a combination of HPAEC-PAD-MS, ESI-MS/MS, and GC-MS techniques. The total amount of degradation products increased with treatment time, and fragmented (glucosyl(n)-erythrose, glucosyl(n)-glycolaldehyde), and dehydrated (glucosyl(n)-levoglucosan) were identified as the main oligomeric degradation products from the cello-oligosaccharides. PMID:25464077

  2. Screening Oligosaccharide Libraries against Lectins Using the Proxy Protein Electrospray Ionization Mass Spectrometry Assay.

    Science.gov (United States)

    Han, Ling; Shams-Ud-Doha, Km; Kitova, Elena N; Klassen, John S

    2016-08-16

    An electrospray ionization mass spectrometry (ESI-MS) assay for screening carbohydrate libraries against lectins is described. The assay is based on the proxy protein ESI-MS method, which combines direct ESI-MS protein-ligand binding measurements and competitive protein binding, to simultaneously detect and quantify protein-carbohydrate interactions. Specific interactions between components of the library and the target protein (PT) are identified from changes in the relative abundances (as measured by ESI-MS) of the carbohydrate complexes of a proxy protein (Pproxy), which binds to all components of the library with known affinity, upon addition of PT to the solution. The magnitude of the change in relative abundance of a given Pproxy-ligand complex provides a quantitative measure of the affinity of the corresponding PT-ligand interaction. A mathematical framework for the implementation of the method in the case of monovalent (single binding site) Pproxy and monovalent and multivalent (multiple equivalent and independent binding sites) PT is described. The application of the method to screen small libraries of oligosaccharides, on the basis of human histo-blood group antigens and milk oligosaccharides, against an N-terminal fragment of the family 51 carbohydrate-binding module, a fucose-binding lectin from Ralstonia solanacearum, and human norovirus VA387 P particle (24-mer of the protruding domain of the capsid protein), serves to demonstrate the reliability and versatility of the assay. PMID:27366913

  3. The Antioxidant Effects of Complexes of Tilapia Fish Skin Collagen and Different Marme Oligosaccharides

    Institute of Scientific and Technical Information of China (English)

    REN Shuwen; LI Jing; GUAN Huashi

    2010-01-01

    An excess of reactive oxygen species(ROS)leads to a variety of chronic health problems.As potent antioxidants,marine bioactive extracts containing oligosaccharides and peptides have been extensively studied.Recently,there is a growing interest in protein-polysaccharide complexes because of their potential uses in pharmaceutical and food industries.However,only few studies are available on the antioxidant activities of such complexes,in terms of their ROS scavenging capability.In this study,we combined and superoxide radicals,and to evaluate the influences on the activities of superoxide dismutase(SOD),glutathione peroxidase(GSH-Px)and the level of malondialdehyde(MDA)in UV-induced photoaging models.The results indicated that the antioxidant activities of all the complexes were stronger than those of their individual components.Among the 11 complexes tested,two complexes,namely MA1000+CP and κ-ca3000+CP,turned out to be highly effective antioxidants.Although the detailed mechanisms of this improved scavenging ability are not fully understood,this work provides insights into the design of highly efficient peptide-oligosaccharide complexes for potential applications in pharmaceutical,cosmetics and food industries.

  4. Characterization of Bacterial Mannanase for Hydrolyzing Palm Kernel Cake to Produce Manno-oligosaccharides Prebiotics

    Directory of Open Access Journals (Sweden)

    W. Utami

    2013-12-01

    Full Text Available Palm kernel cake (PKC is a promising source of prebiotics, since it contains high amount of β-mannan which can be further hydrolyzed to manno-oligasaccharides (MOS, a prebiotic. Therefore, this research was carried out to analyze the capability of a bacterial isolate (A2 isolates previously isolated from soils sample from around IPB campus to hydrolyze PKC. Based on 16S-DNA analysis, isolate A2 was identified as Brevibacillus borstelensis. Mannanase of A2 isolate had an optimum condition at 90 oC and pH 7. Mannanase activity of crude extracts using Locust Bean Gum (LBG and PKC as substrates were 0.37U/mL and 0.032U/mL, respectively. However, the most favorable production of oligosaccharides based on the degree of polymerization was obtained after 72-h of incubation with the ratio of substrate:enzyme, 1.2:1, on 1.5% PKC as substrate. The manno-oligosaccharides prebio-tic obtained was found to interfere the growth of both lactic acid bacteria (Lactobacillus casei and pathogenic microflora (Escherichia coli. E. coli apparently could not use this prebiotic as the carbon sources, in contrast to L. casei. Substitution of carbon source in medium with prebiotics reduced the capability of L. casei to produce organic acids. It is concluded that local A2 isolate (B. borstelensis produces mannanase which can be used to produce prebiotics from PKC.

  5. Microanalysis of oligosaccharide HS203 in beagle dog plasma by postcolumn fluorescence derivatization method.

    Science.gov (United States)

    Sun, Shumeng; Zhao, Xia; Li, Guangsheng; Yu, Guangli; Xing, Xiaoxu; Zeng, Yangyang; Wu, Jian; Wang, Jianing

    2012-06-20

    A rapid and sensitive postcolumn fluorescence derivatization method was developed for microanalysis of antidiabetic oligosaccharide HS203 in beagle dog plasma. After plasma protein was removed by a simple and fast ultrafiltration method, chromatographic separation was performed on an Asahipak GS-320 HQ column with a mobile phase of 50 mmol/L phosphate buffer (pH 6.7) and acetonitrile (83/17, v/v). The column effluent was monitored by fluorescence detection at 249 nm (excitation) and 435 nm (emission) using guanidine hydrochloride as a postcolumn derivatizing reagent. A satisfactory resolution of the analyte was achieved and the limit of detection was found to be 4 ng (more sensitive than silver staining of HS203 in polyacrylamide gel electrophoresis). The method described above was successfully applied to a pharmacokinetic study of HS203 and to monitor blood glucose level simultaneously in beagle dog. It is also possible to be applied for microanalysis of other oligosaccharides in biological samples. PMID:24750771

  6. Fructo-oligosaccharide production from inulin through partial citric or phosphoric acid hydrolyses.

    Science.gov (United States)

    Fontana, José Domingos; Grzybowski, Adelia; Tiboni, Marcela; Passos, Maurício

    2011-11-01

    Purified inulin from Dahlia tubers was partially hydrolyzed to form fructo-oligosaccharides by using citric or phosphoric acids (pH, 2.0-2.5) as mild acid catalysts. The ideal kinetic conditions to ensure a high yield of fructo-oligosaccharides relative to free fructose were a temperature range of 85°C-95°C, a hydrolysis time of 15-25 minutes, and a catalyst pH of 2.5. At the higher temperature and the longest hydrolysis time, an inversion of the product ratio occurred. Under these conditions, co-generation of hydroxymethylfurfural occurred, and it was eliminated by activated charcoal. Unlike in classic hydrolysis with hydrochloric or sulfuric acid, deionization of the actual hydrolysates was not necessary because the catalyst neutralization with common bases results in the formation of co-nutrients with alternative uses as foods or fermentation substrates. These whole hydrolysates can be advantageously added as nutraceuticals to carbonated beverages and acidic foods, such as soft drinks and yogurts. PMID:21663491

  7. Separation and sugar component analysis of the oligosaccharides in the surface glycoproteins of newcastle disease virus

    International Nuclear Information System (INIS)

    The precursor glycoproteins HN0 and F0 in the surface spikes of Newcastle Disease Virus strain Ulster as produced by MDBK cells, were found to contain 10.4 and 11.9 weight per cent, respectively, of the sugars typical for N-glycosidically linked glycoprotein glycans. A molar ratio of D-mannose:D-galactose:L-fucose:N-acetyl-D-glucosamine approaching 1.0:1.1:0.5:1.0 was found for HN0, and of 1.0:0.7:0.3:0.6 for F0. By a sequence of degradation (with pronase, with endo-β-N-acetylglucosaminidase H [endo H], and by hydrazinolysis) and separation procedures (Concanavalin A-affinity and Biogel P-4 chromatography), the radiolabelled carbohydrate moieties of NDV HN0 and F0 (as oligosaccharitols) were separated into (at least) ten and eight fractions, respectively. Separate in vivo labelling with tritiated derivatives of the four sugars showed that both glycoproteins contain oligosaccharides of the oligomannosidic ('high mannose'), of the N-acetyllactosaminic ('complex'), as well as of the 'mixed type). The majority of the oligosaccharides in F0, but not of those in HNsub0, was found to be endo H-sensitive. (Author)

  8. In vitro digestion and fermentation properties of linear sugar-beet arabinan and its oligosaccharides.

    Science.gov (United States)

    Moon, Jin Seok; Shin, So Yeon; Choi, Hye Sun; Joo, Wooha; Cho, Seung Kee; Li, Ling; Kang, Jung-Hyun; Kim, Tae-Jip; Han, Nam Soo

    2015-10-20

    This study was conducted to investigate the prebiotic effects of linear arabino-oligosaccharides (LAOS) and debranched (linear) sugar beet arabinan (LAR) for the development of new prebiotics. LAOS were prepared from LAR by enzymatic hydrolysis with endo-arabinanase from Bacillus licheniformis, followed by removal of the arabinose fraction by incubation with resting cells of Leuconostoc mesenteroides. The resulting LAOS contained DP2 (28.7%), DP3 (49.9%), DP4 (20.1%), and DP5 (1.16%). A standardized digestibility test showed that LAOS and LAR were not digestible. Individual cultures of 24 strains of gastrointestinal bacteria showed that LAOS and LAR stimulated growth of Lactobacillus brevis, Bifidobacterium longum, and Bacteroides fragilis. In vitro batch fermentation using human fecal samples showed that LAOS had higher bifidogenic properties than LAR; LAOS increased the population of bifidobacteria which produced short-chain fatty acids (SCFAs). LAOS was fermented slowly compared to fructo-oligosaccharides and this may permit SCFA production in the distal colon. This study demonstrates that LAOS prepared from LAR are promising dietary substrates for improvement of human intestinal health. PMID:26256159

  9. Purification, characterization, and prebiotic properties of pectic oligosaccharides from orange peel wastes.

    Science.gov (United States)

    Gómez, Belén; Gullón, Beatriz; Remoroza, Connie; Schols, Henk A; Parajó, Juan C; Alonso, José L

    2014-10-01

    Pectic oligosaccharides (POS) were obtained by hydrothermal treatment of orange peel wastes (OPW) and purified by membrane filtration to yield a refined product containing 90 wt % of the target products. AraOS (DP 3-21), GalOS (DP 5-12), and OGalA (DP 2-12, with variable DM) were identified in POS mixtures, but long-chain products were also present. The prebiotic potential of the concentrate was assessed by in vitro fermentation using human fecal inocula. For comparative purposes, similar experiments were performed using orange pectin and commercial fructo-oligosaccharides (FOS) as substrates for fermentation. The dynamics of selected microbial populations was assessed by fluorescent in situ hybridization (FISH). Gas generation, pH, and short-chain fatty acid (SCFA) production were also measured. Under the tested conditions, all of the considered substrates were utilized by the microbiota, and fermentation resulted in increased numbers of all the bacterial groups, but the final profile of the microbial population depended on the considered carbon source. POS boosted particularly the numbers of bifidobacteria and lactobacilli, so that the ratio between the joint counts of both genera and the total cell number increased from 17% in the inocula to 27% upon fermentation. SCFA generation from POS fermentation was similar to that observed with FOS, but pectin fermentation resulted in reduced butyrate generation. PMID:25207862

  10. Nitric oxide mediates alginate oligosaccharides-induced root development in wheat (Triticum aestivum L.).

    Science.gov (United States)

    Zhang, Yunhong; Liu, Hang; Yin, Heng; Wang, Wenxia; Zhao, Xiaoming; Du, Yuguang

    2013-10-01

    Alginate oligosaccharides (AOS), which are marine oligosaccharides, are involved in regulating plant root growth, but the promotion mechanism for AOS remains unclear. Here, AOS (10-80 mg L(-1)) were found to induce the generation of nitric oxide (NO) in the root system of wheat (Triticum aestivum L.), which promoted the formation and elongation of wheat roots in a dose-dependent manner. NO inhibitors suggested that nitrate reductase (NR), rather than nitric oxide synthase (NOS), was essential for AOS-induced root development. Further studies confirmed that AOS-induced NO generation in wheat roots by up-regulating the gene expression and enzyme activity of NR at the post-transcriptional level. The anatomy and RT-PCR results showed that AOS accelerated the division and growth of stele cells, leading to an increase in the ratio of stele area to root transverse area. This could be inhibited by the NR inhibitor, sodium tungstate, which indicated that NO catalyzed by the NR was involved in AOS regulation of root development. Taken together, in the early stage of AOS-induced root development, NO generation was a novel mechanism by which AOS regulated plant growth. The results also showed that this marine resource could be widely used for crop development.

  11. A C4-oxidizing lytic polysaccharide monooxygenase cleaving both cellulose and cello-oligosaccharides.

    Science.gov (United States)

    Isaksen, Trine; Westereng, Bjørge; Aachmann, Finn L; Agger, Jane W; Kracher, Daniel; Kittl, Roman; Ludwig, Roland; Haltrich, Dietmar; Eijsink, Vincent G H; Horn, Svein J

    2014-01-31

    Lignocellulosic biomass is a renewable resource that significantly can substitute fossil resources for the production of fuels, chemicals, and materials. Efficient saccharification of this biomass to fermentable sugars will be a key technology in future biorefineries. Traditionally, saccharification was thought to be accomplished by mixtures of hydrolytic enzymes. However, recently it has been shown that lytic polysaccharide monooxygenases (LPMOs) contribute to this process by catalyzing oxidative cleavage of insoluble polysaccharides utilizing a mechanism involving molecular oxygen and an electron donor. These enzymes thus represent novel tools for the saccharification of plant biomass. Most characterized LPMOs, including all reported bacterial LPMOs, form aldonic acids, i.e., products oxidized in the C1 position of the terminal sugar. Oxidation at other positions has been observed, and there has been some debate concerning the nature of this position (C4 or C6). In this study, we have characterized an LPMO from Neurospora crassa (NcLPMO9C; also known as NCU02916 and NcGH61-3). Remarkably, and in contrast to all previously characterized LPMOs, which are active only on polysaccharides, NcLPMO9C is able to cleave soluble cello-oligosaccharides as short as a tetramer, a property that allowed detailed product analysis. Using mass spectrometry and NMR, we show that the cello-oligosaccharide products released by this enzyme contain a C4 gemdiol/keto group at the nonreducing end. PMID:24324265

  12. A C4-oxidizing Lytic Polysaccharide Monooxygenase Cleaving Both Cellulose and Cello-oligosaccharides*

    Science.gov (United States)

    Isaksen, Trine; Westereng, Bjørge; Aachmann, Finn L.; Agger, Jane W.; Kracher, Daniel; Kittl, Roman; Ludwig, Roland; Haltrich, Dietmar; Eijsink, Vincent G. H.; Horn, Svein J.

    2014-01-01

    Lignocellulosic biomass is a renewable resource that significantly can substitute fossil resources for the production of fuels, chemicals, and materials. Efficient saccharification of this biomass to fermentable sugars will be a key technology in future biorefineries. Traditionally, saccharification was thought to be accomplished by mixtures of hydrolytic enzymes. However, recently it has been shown that lytic polysaccharide monooxygenases (LPMOs) contribute to this process by catalyzing oxidative cleavage of insoluble polysaccharides utilizing a mechanism involving molecular oxygen and an electron donor. These enzymes thus represent novel tools for the saccharification of plant biomass. Most characterized LPMOs, including all reported bacterial LPMOs, form aldonic acids, i.e., products oxidized in the C1 position of the terminal sugar. Oxidation at other positions has been observed, and there has been some debate concerning the nature of this position (C4 or C6). In this study, we have characterized an LPMO from Neurospora crassa (NcLPMO9C; also known as NCU02916 and NcGH61–3). Remarkably, and in contrast to all previously characterized LPMOs, which are active only on polysaccharides, NcLPMO9C is able to cleave soluble cello-oligosaccharides as short as a tetramer, a property that allowed detailed product analysis. Using mass spectrometry and NMR, we show that the cello-oligosaccharide products released by this enzyme contain a C4 gemdiol/keto group at the nonreducing end. PMID:24324265

  13. Characterisation of branched gluco-oligosaccharides to study the mode-of-action of a glucoamylase from Hypocrea jecorina

    NARCIS (Netherlands)

    Jonathan, M.C.; Brussel, van M.; Scheffers, M.S.; Kabel, M.A.

    2015-01-01

    In the conversion of starch to fermentable glucose for bioethanol production, hydrolysis of amylopectin by a-amylases and glucoamylases is the slowest step. In this process, a-1,6-branched gluco-oligosaccharides accumulate and are slowly degraded. Glucoamylases that are able to degrade such branched

  14. Structural Analysis of an Oligosaccharide and Glycopeptide Mixture from Panax Ginseng Root with Inhibition SHP-1 Function

    Institute of Scientific and Technical Information of China (English)

    WANG Ying; GAO Qi-pin; LI Gui-rong; CHEN Ying-hong; LUO Hao-ming; GAO Yang; JIANG Rui-zhi

    2011-01-01

    A mixture of oligosaccharide and glycopeptide was isolated from the aqueous extract of Panax ginseng roots.The mixture inhibits protein tyrosine phosphatase(SHP-1)function,implying it enhances immune activity.The peak molecular mass of the oligosaccharide portion is 1800 calculated via GPC software after separation by HPLC.And the structure of the oligosaccharide portion is the backbone of(1→3)-and(1→4)-linked arabinopyranoside,and (1→4)-and(l→6)-linked glucopyranoside,with non-reducing terminals of arabinopyranoside and glucopyranoside.The peak molecular mass of glycopeptide portion is 1900 calculated via GPC software after separation by HPLC. The structure of glycopeptide portion is the backbone of(1→3)-and(1→4)-linked arabinopyranoside,and (l→3,6)-linked glucopyranoside,with non-reducing terminals of galactopyranose and glucopyranoside.The peptide composition is Glu,Asp,Hyp,Ser,Arg,Gly,Thr,Pro,Ala,Val,lle,Leu and Lys.The oligosaccharide-peptide linkage is formed by Ara and Hyp.

  15. Multiple applications of ion chromatography oligosaccharide fingerprint profiles to solve a variety of sugar and sugar-biofuel industry problems.

    Science.gov (United States)

    Eggleston, Gillian; Borges, Eduardo

    2015-03-25

    Sugar crops contain a broad variety of carbohydrates used for human consumption and the production of biofuels and bioproducts. Ion chromatography with integrated pulsed amperometric detection (IC-IPAD) can be used to simultaneously detect mono-, di-, and oligosaccharides, oligosaccharide isomers, mannitol, and ethanol in complex matrices from sugar crops. By utilizing a strong NaOH/NaOAc gradient method over 45 min, oligosaccharides of at least 2-12 dp can be detected. Fingerprint IC oligosaccharide profiles are extremely selective, sensitive, and reliable and can detect deterioration product metabolites from as low as 100 colony-forming units/mL lactic acid bacteria. The IC fingerprints can also be used to (i) monitor freeze deterioration, (ii) optimize harvesting methods and cut-to-crush times, (iii) differentiate between white refined sugar from sugar cane and from sugar beets, (iv) verify the activities of carbohydrate enzymes, (v) select yeasts for ethanol fermentations, and (vi) isolate and diagnose infections and processing problems in sugar factories.

  16. 3-O-sulfated oligosaccharide structures are recognized by anti-heparan sulfate antibody HS4C3.

    NARCIS (Netherlands)

    Dam, G.B. ten; Kurup, S.; Westerlo, E.M. van de; Versteeg, E.M.M.; Lindahl, U.; Spillmann, D.; Kuppevelt, A.H.M.S.M. van

    2006-01-01

    Antibodies against heparan sulfate (HS) are useful tools to study the structural diversity of HS. They demonstrate the large sequential variation within HS and show the distribution of HS oligosaccharide sequences within their natural environment. We analyzed the distribution and the structural char

  17. Oligosaccharide and Creatine Supplementation on Glucose and Urea Nitrogen in Blood and Serum Creatine Kinase in Basketball Athletes

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The effects of oligosaccharide and creatine (Cr) supplementation on glucose, lactic acid and urea nitrogen levels in blood and activity of serum creatine kinase (CK) were explored. Twenty CUBA male athletes were divided into 4 groups: group A (supplementation of Cr alone), group B (supplementation of oligosaccharide), group C (supplementation of oligosaccharide and Cr) and group D (placebo control group). By using orthogonal L4 table (23), the experiment was performed. There were factors including oligosaccharide (carbohydrate, CHO), Cr and their correlation. Each factor had two levels: supplementation and no-supplementation. The results showed that the supplementation of CHO or Cr alone, combined supplementation of CHO and Cr could significantly reduce the glucose, urea nitrogen levels in blood and serum CK activity after competition in the athletes. Moreover, the effects of combined supplementation of CHO and Cr were more satisfactory. It was concluded that supplementation of CHO and Cr could promote the recovery of physical performance and athletic abilities after athletics in basketball athletes.

  18. Conformational energy calculations and proton nuclear overhauser enhancements reveal a unique conformation for blood group A oligosaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Bush, C.A.; Yan, Z.Y.; Rao, B.N.N.

    1986-10-01

    The H NMR spectra of a series of blood group A active oligosaccharides containing from four to ten sugar residues have been completely assigned, and quantitative nuclear Overhauser enhancements (NOE) have been measured between protons separated by known distances within the pyranoside ring. The observation of NOE between anomeric protons and those of the aglycon sugar as well as small effects between protons of distant rings suggests that the oligosaccharides have well-defined conformations. Conformational energy calculations were carried out on a trisaccharide, Fuc( -1 2)(GalNAc( -1 3))-GalUS -O-me, which models the nonreducing terminal fragments of the blood group A oligosaccharides. The results of calculations with three different potential energy functions which have been widely used in peptides and carbohydrates gave several minimum energy conformations. In NOE calculations from conformational models, the rotational correlation time was adjusted to fit T1's and intra-ring NOE. Comparison of calculated maps of NOE as a function of glycosidic dihedral angles showed that only a small region of conformational space was consistent with experimental data on a blood group A tetrasaccharide alditol. This conformation occurs at an energy minimum in all three energy calculations. Temperature dependence of the NOE implies that the oligosaccharides adopt single rigid conformations which do not change with temperature.

  19. Structure determination of oligosaccharides isolated from Cad erythrocyte membranes by permethylation analysis and 500-MHz 1H-NMR spectroscopy

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Herkt, F.; Paz Parente, J.; Leroy, Y.; Fournet, B.; Blanchard, D.; Cartron, J.-P.; Halbeek, H. van

    1985-01-01

    Alkaline borohydride reductive cleavage (beta-elimination) of glycophorin A isolated from one individual of the rare blood group Cad, resulted in the release of six acidic oligosaccharide-alditols which were separated by high-performance liquid chromatography (HPLC) on an alkyl amine silicagel colum

  20. Short-chain fructo-oligosaccharides improve magnesium absorption in adolescent girls with a low calcium intake

    NARCIS (Netherlands)

    Heuvel, E.G.H.M. van den; Muijs, T.; Brouns, F.; Hendriks, H.F.J.

    2009-01-01

    Consumption of fructo-oligosaccharides (FOS) has been shown to improve mineral absorption in the short term, but no long-term effects were studied in girls with a low calcium intake. Therefore, we hypothesized that short- and long-term consumption of short-chain FOS (sc-FOS) improves calcium and mag

  1. Supplementing pregnant mice with a specific mixture of nondigestible oligosaccharides reduces symptoms of allergic asthma in male offspring

    NARCIS (Netherlands)

    Hogenkamp, Astrid; Thijssen, Suzan; van Vlies, Naomi; Garssen, Johan

    2015-01-01

    BACKGROUND: Previously, maternal supplementation with short-chain galacto- and long-chain fructo-oligosaccharides (scGOS/lcFOS; ratio 9:1) was shown to affect maternal and fetal immune status in mice. OBJECTIVE: This study was designed to test the long-term effects of supplementation of mice with sc

  2. Multiple applications of ion chromatography oligosaccharide fingerprint profiles to solve a variety of sugar and sugar-biofuel industry problems.

    Science.gov (United States)

    Eggleston, Gillian; Borges, Eduardo

    2015-03-25

    Sugar crops contain a broad variety of carbohydrates used for human consumption and the production of biofuels and bioproducts. Ion chromatography with integrated pulsed amperometric detection (IC-IPAD) can be used to simultaneously detect mono-, di-, and oligosaccharides, oligosaccharide isomers, mannitol, and ethanol in complex matrices from sugar crops. By utilizing a strong NaOH/NaOAc gradient method over 45 min, oligosaccharides of at least 2-12 dp can be detected. Fingerprint IC oligosaccharide profiles are extremely selective, sensitive, and reliable and can detect deterioration product metabolites from as low as 100 colony-forming units/mL lactic acid bacteria. The IC fingerprints can also be used to (i) monitor freeze deterioration, (ii) optimize harvesting methods and cut-to-crush times, (iii) differentiate between white refined sugar from sugar cane and from sugar beets, (iv) verify the activities of carbohydrate enzymes, (v) select yeasts for ethanol fermentations, and (vi) isolate and diagnose infections and processing problems in sugar factories. PMID:25708094

  3. Conformational energy calculations and proton nuclear overhauser enhancements reveal a unique conformation for blood group A oligosaccharides

    International Nuclear Information System (INIS)

    The 1H NMR spectra of a series of blood group A active oligosaccharides containing from four to ten sugar residues have been completely assigned, and quantitative nuclear Overhauser enhancements (NOE) have been measured between protons separated by known distances within the pyranoside ring. The observation of NOE between anomeric protons and those of the aglycon sugar as well as small effects between protons of distant rings suggests that the oligosaccharides have well-defined conformations. Conformational energy calculations were carried out on a trisaccharide, Fuc(α-1→2)[GalNAc(α-1→3)]-Galβ-O-me, which models the nonreducing terminal fragments of the blood group A oligosaccharides. The results of calculations with three different potential energy functions which have been widely used in peptides and carbohydrates gave several minimum energy conformations. In NOE calculations from conformational models, the rotational correlation time was adjusted to fit T1's and intra-ring NOE. Comparison of calculated maps of NOE as a function of glycosidic dihedral angles showed that only a small region of conformational space was consistent with experimental data on a blood group A tetrasaccharide alditol. This conformation occurs at an energy minimum in all three energy calculations. Temperature dependence of the NOE implies that the oligosaccharides adopt single rigid conformations which do not change with temperature

  4. Effect of nondigestible oligosaccharides on large-bowel functions, blood lipid concentrations and glucose absorption in young healthy male subjects

    NARCIS (Netherlands)

    Dokkum, W. van; Wezendonk, B.; Srikumar, T.S.; Heuvel, E.G.H.M. van den

    1999-01-01

    Objective: To study the effect of the intake of 15 g nondigestible oligosaccharides per day on various parameters of large-bowel function, as well as on blood lipid concentrations and glucose absorption in man. Design: Latin square, randomized, double-blind, diet-controlled. Setting: Metabolic resea

  5. Safety evaluation of pectin-derived acidic oligosaccharides (pAOS): Genotoxicity and sub-chronic studies

    NARCIS (Netherlands)

    Garthoff, J.A.; Heemskerk, S.; Hempenius, R.A.; Lina, B.A.R.; Krul, C.A.M.; Koeman, J.H.; Speijers, G.J.A.

    2010-01-01

    Pectin-derived acidic oligosaccharides (pAOS) are non-digestible carbohydrates to be used in infant formulae and medical nutrition. To support its safety, the genotoxic potential of pAOS was evaluated. pAOS was not mutagenic in the Ames test. Positive results were obtained in the chromosome aberrati

  6. Self-Assembly of Oligosaccharide-b-PMMA Block Copolymer Systems: Glyco-Nanoparticles and Their Degradation under UV Exposure.

    Science.gov (United States)

    Zepon, Karine M; Otsuka, Issei; Bouilhac, Cécile; Muniz, Edvani C; Soldi, Valdir; Borsali, Redouane

    2016-05-10

    This paper discusses the self-assembly of oligosaccharide-containing block copolymer and the use of ultraviolet (UV) to obtain nanoporous glyco-nanoparticles by photodegradation of the synthetic polymer block. Those glyco-nanoparticles consisting of oligosaccharide-based shell and a photodegradable core domain were obtained from the self-assembly of maltoheptaose-block-poly(methyl methacrylate) (MH-b-PMMA48) using the nanoprecipitation protocol. MH-b-PMMA48 self-assembled into well-defined spherical micelles (major compound) with a hydrodynamic radius (Rh) of ca. 10 nm and also into large compound micellar aggregates (minor compound) with an Rh of ca. 65 nm. The oligosaccharide shells of these glyco-nanoparticles were cross-linked through the Michael-type addition of divinyl sulfone under dilute conditions to minimize the intermicellar cross-linking. The core domain photodegradation of the cross-linked glyco-nanoparticles was induced under exposure to 254 nm UV radiation, resulting in porous glyco-nanoparticles with an Rh of ca. 44 nm. The morphology of the cross-linked shell and the core photodegradation of these glyco-nanoparticles were characterized using static light scattering, dynamic light scattering, Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, field-emission gun-scanning electron microscopy, and transmission electron microscopy. The innovative aspect of this approach concerns the fact that after removing the PMMA domains the porous nanoparticles are mostly composed of biocompatible and nontoxic oligosaccharides. PMID:27054350

  7. Isolation and Structural Characterization of an Oligosaccharide Produced by Bacillus subtilis in a Maltose-Containing Medium.

    Science.gov (United States)

    Shin, Kwang-Soon

    2016-06-01

    Among 116 bacterial strains isolated from Korean fermented foods, one strain (SS-76) was selected for producing new oligosaccharides in a basal medium containing maltose as the sole source of carbon. Upon morphological characterization using scanning electron microscopy, the cells of strain SS-76 appeared rod-shaped; subsequent 16S rRNA gene sequence analysis revealed that strain SS-76 was phylogenetically close to Bacillus subtilis. The main oligosaccharide fraction B extracted from the culture supernatant of B. subtilis SS-76 was purified by high performance liquid chromatography. Subsequent structural analysis revealed that this oligosaccharide consisted only of glucose, and methylation analysis indicated similar proportions of glucopyranosides in the 6-linkage, 4-linkage, and non-reducing terminal positions. Matrix-assisted laser-induced/ionization time-of-flight/mass spectrometry and electrospray ionization-based liquid chromatography-mass spectrometry/mass spectrometry analyses suggested that this oligosaccharide consisted of a trisaccharide unit with 1,6- and 1,4-glycosidic linkages. The anomeric signals in the (1)H-nuclear magnetic resonance spectrum corresponded to α-anomeric configurations, and the trisaccharide was finally identified as panose (α-D-glucopyranosyl-1,6-α-D-glucopyranosyl-1,4-D-glucose). These results suggest that B. subtilis SS-76 converts maltose into panose; strain SS-76 may thus find industrial application in the production of panose. PMID:27390729

  8. Isolation and Structural Characterization of an Oligosaccharide Produced by Bacillus subtilis in a Maltose-Containing Medium

    Science.gov (United States)

    Shin, Kwang-Soon

    2016-01-01

    Among 116 bacterial strains isolated from Korean fermented foods, one strain (SS-76) was selected for producing new oligosaccharides in a basal medium containing maltose as the sole source of carbon. Upon morphological characterization using scanning electron microscopy, the cells of strain SS-76 appeared rod-shaped; subsequent 16S rRNA gene sequence analysis revealed that strain SS-76 was phylogenetically close to Bacillus subtilis. The main oligosaccharide fraction B extracted from the culture supernatant of B. subtilis SS-76 was purified by high performance liquid chromatography. Subsequent structural analysis revealed that this oligosaccharide consisted only of glucose, and methylation analysis indicated similar proportions of glucopyranosides in the 6-linkage, 4-linkage, and non-reducing terminal positions. Matrix-assisted laser-induced/ionization time-of-flight/mass spectrometry and electrospray ionization-based liquid chromatography-mass spectrometry/mass spectrometry analyses suggested that this oligosaccharide consisted of a trisaccharide unit with 1,6- and 1,4-glycosidic linkages. The anomeric signals in the 1H-nuclear magnetic resonance spectrum corresponded to α-anomeric configurations, and the trisaccharide was finally identified as panose (α-D-glucopyranosyl-1,6-α-D-glucopyranosyl-1,4-D-glucose). These results suggest that B. subtilis SS-76 converts maltose into panose; strain SS-76 may thus find industrial application in the production of panose. PMID:27390729

  9. Analysis of human milk oligosaccharides using high-performance anion-exchange chromatography with pulsed amperometric detection

    DEFF Research Database (Denmark)

    Lie, Aleksander; Pedersen, Lars Haastrup

    Human Milk Oligosaccharides (HMOs) are composed of 5 different monosaccharides: D-glucose, D-galactose, L-fucose, N-acetylneuraminic acid and N-acetylglucosamine. Approximately 200 unique structures have been identified, ranging in the degree of polymerization from 3 to 22. The diversity among...

  10. Separation of human milk oligosaccharides using high-performance anion-exchange chromatography with pulsed amperometric detection

    DEFF Research Database (Denmark)

    Lie, Aleksander; Pedersen, Lars Haastrup

    Human Milk Oligosaccharides (HMOs) are composed of 5 different monosaccharides: D-glucose, D galactose, L-fucose, N-acetylneuraminic acid and N-acetylglucosamine. Approximately 200 unique structures have been identified, ranging in degree of polymerization from 3 to 22. The diversity among...

  11. Effects of arabinoxylan-oligosaccharides (AXOS) on juvenile Siberian sturgeon (Acipenser baerii) performance, immune responses and gastrointestinal microbial community

    NARCIS (Netherlands)

    Geraylou, Z.; Souffreau, C.; Rurangwa, E.; Hondt, D' S.; Callewaert, L.; Courtin, C.M.; Delcour, J.A.; Buyse, J.; Ollevier, F.

    2012-01-01

    Arabinoxylan-oligosaccharides (AXOS) are a newly discovered class of candidate prebiotics that exert different properties depending on their structure. In this study the effects of two different structures of AXOS, namely AXOS-32-0.30 (average degree of polymerization: 32, average degree of substitu

  12. Effects of dietary non-digestible oligosaccharides on microbial characteristics of ileal chyme and faeces in weaner pigs

    NARCIS (Netherlands)

    Houdijk, J.G.M.; Hartemink, R.; Verstegen, M.W.A.; Bosch, M.W.

    2002-01-01

    Fructooligosaccharides (FOS) and transgalactooligosaccharides (TOS), which are non-digestible oligosaccharides (NDO), were included at 10 and 40 g/kg in an NDO--free control diet at the expense of purified cellulose. Each of the 5 diets was fed to 4 weaner pigs and microbial characteristics of their

  13. Rapid Screening of Bovine Milk Oligosaccharides in a Whey Permeate Product and Domestic Animal Milks by Accurate Mass Database and Tandem Mass Spectral Library.

    Science.gov (United States)

    Lee, Hyeyoung; Cuthbertson, Daniel J; Otter, Don E; Barile, Daniela

    2016-08-17

    A bovine milk oligosaccharide (BMO) library, prepared from cow colostrum, with 34 structures was generated and used to rapidly screen oligosaccharides in domestic animal milks and a whey permeate powder. The novel library was entered into a custom Personal Compound Database and Library (PCDL) and included accurate mass, retention time, and tandem mass spectra. Oligosaccharides in minute-sized samples were separated using nanoliquid chromatography (nanoLC) coupled to a high resolution and sensitive quadrupole-Time of Flight (Q-ToF) MS system. Using the PCDL, 18 oligosaccharides were found in a BMO-enriched product obtained from whey permeate processing. The usefulness of the analytical system and BMO library was further validated using milks from domestic sheep and buffaloes. Through BMO PCDL searching, 15 and 13 oligosaccharides in the BMO library were assigned in sheep and buffalo milks, respectively, thus demonstrating significant overlap between oligosaccharides in bovine (cow and buffalo) and ovine (sheep) milks. This method was shown to be an efficient, reliable, and rapid tool to identify oligosaccharide structures using automated spectral matching. PMID:27428379

  14. New observation on a class of old reactions:Chemoselectivity for the solvent-free reaction of aromatic aldehydes with alkylketones catalyzed by a double-component inorganic base system

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Solvent-free reactions of aromatic aldehydes with three representative ketones,including acetophenone,acetone and cyclohexanone,have been examined under the catalysis of a low-cost inorganic base system consisting of NaOH and K2CO3.It was found that the chemoselectivity of the reactions is in close relationship with the composition of the reactants and the doublecomponent catalyst.Under the optimized experimental conditions,1,2,3,4,5-pentasubstituted cyclohexanols,α,β-unsaturated ketones and Claisen-Schmidt bicondensation products were obtained in high yields.Two Kostanecki’s triketones were separated,The composition and structure were affirmed by X-ray crystallographic analysis.

  15. 甘薯淀粉加工废渣制备复合寡糖的条件优化及其活性评价%Optimization and Functional Assessment of Oligosaccharides Compound Prepared by Sweet Potato Residue

    Institute of Scientific and Technical Information of China (English)

    董向艳; 李静梅; 石波; 彭晴; 乔宇; Ojokoh Eromosele; 张迷敏

    2014-01-01

    could elicit glyceollins accumulation in soybean.[Result]The enzyme reaction conditions for the solubilization were optimized to be addition of 6.9×103 Uβ-glucanase by weight of sweet potato residue dietary fiber, 7 h treatment at pH3.5, temperature at 40℃, and substrate concentration at 1%. Under these conditions, cello-oligosaccharides were mainly cellobiose, the yield of cellobiose was 100.6 mg·g-1 sweet potato residue dietary fiber, and the conversion rate of cellobiose was 22.37%. The enzyme reaction conditions for the solubilization were optimized to be addition of 1.42×104 U polygalacturonse by weight of sweet potato residue dietary fiber, 4 h treatment at pH2.5, and temperature at 40℃. Using the optimum conditions, the yield of pectic oligosaccharides mainly with a degree of polymerization (DP) of 2 and 3, the yield of digalacturonic acid and trigalacturonic acid was 17.43 mg·g-1, the conversion rate of digalacturonic acid and trigalacturonic acid was 29.9%. The optimum conditions for producing oligosaccharides compound were as follows: temperature at 40℃, pH2.5, concentration of sweet potato residue at1%, the additive amount of β-glucanase was 6.9×103U·g-1 and the additive amount of polygalacturonse was 1.42×104 U·g-1, and the reaction time was 7 h. Using the optimum conditions, the yield of oligosaccharides compound mainly with a DP of 2 and 3, and the yield of cellobiose was 136.97 mg·g-1, the conversion rate of cellobiose was 33.57%, the yield of digalacturonic acid and trigalacturonic acid was 25.95 mg·g-1, the conversion rate of digalacturonic acid and trigalacturonic acid was 44.53%. Oligosaccharides compound was used to induce glyceollins synthesis in soybean seeds. The optimal conditions of elicitation were as follows: concentration of oligosaccharides compound 1%, presoaked in the sterile water for 5 h, stored at a controlled temperature of 25℃ and humidity of 50% in dark for 4 d, the yield of glyceollins elicited by

  16. Simple, chemoselective, catalytic olefin isomerization.

    Science.gov (United States)

    Crossley, Steven W M; Barabé, Francis; Shenvi, Ryan A

    2014-12-01

    Catalytic amounts of Co(Sal(tBu,tBu))Cl and organosilane irreversibly isomerize terminal alkenes by one position. The same catalysts effect cycloisomerization of dienes and retrocycloisomerization of strained rings. Strong Lewis bases like amines and imidazoles, and labile functionalities like epoxides, are tolerated.

  17. Comparison of biological activities of human antithrombins with high-mannose or complex-type nonfucosylated N-linked oligosaccharides.

    Science.gov (United States)

    Yamada, Tsuyoshi; Kanda, Yutaka; Takayama, Makoto; Hashimoto, Akitoshi; Sugihara, Tsutomu; Satoh-Kubota, Ai; Suzuki-Takanami, Eri; Yano, Keiichi; Iida, Shigeru; Satoh, Mitsuo

    2016-05-01

    The structure of the N-linked oligosaccharides attached to antithrombin (AT) has been shown to affect its anticoagulant activity and pharmacokinetics. Human AT has biantennary complex-type oligosaccharides with the unique feature of lacking a core fucose, which affects its biological activities by changing its heparin-binding affinity. In human plasma, AT circulates as a mixture of the α-form bearing four oligosaccharides and the β-form lacking an oligosaccharide at Asn135. However, it remains unclear how the immature high-mannose-type oligosaccharides produced by mammalian cells affect biological activities of AT. Here, we succeeded in directly comparing the activities between the high-mannose and complex types. Interestingly, although there were no substantial differences in thrombin inhibitory activity, the high-mannose type showed higher heparin-binding affinity. The anticoagulant activities were increased by heparin and correlated with the heparin-binding affinity, resulting in the strongest anticoagulant activity being displayed in the β-form with the high-mannose type. In pharmacokinetic profiling, the high-mannose type showed a much shorter plasma half-life than the complex type. The β-form was found to have a prolonged plasma half-life compared with the α-form for the high-mannose type; conversely, the α-form showed a longer half-life than the β-form for the complex-type. The present study highlights that AT physiological activities are strictly controlled not only by a core fucose at the reducing end but also by the high-mannose-type structures at the nonreducing end. The β-form with the immature high-mannose type appears to function as a more potent anticoagulant than the AT typically found in human plasma, once it emerges in the blood. PMID:26747427

  18. Isomalto oligosaccharide sulfate inhibits tumor growth and metastasis of hepatocellular carcinoma in nude mice

    International Nuclear Information System (INIS)

    Hepatocellular carcinoma (HCC) usually has a dismal prognosis because of its limited response to current pharmacotherapy and high metastatic rate. Sulfated oligosaccharide has been confirmed as having potent antitumor activities against solid tumors. Here, we explored the preclinical effects and molecular mechanisms of isomalto oligosaccharide sulfate (IMOS), another novel sulfated oligosaccharide, in HCC cell lines and a xenograft model. The effects of IMOS on HCC proliferation, apoptosis, adhesion, migration, and invasiveness in vitro were assessed by cell counting, flow cytometry, adhesion, wound healing, and transwell assays, respectively. The roles of IMOS on HCC growth and metastasis in xenograft models were evaluated by tumor volumes and fluorescent signals. Total and phosphorylated protein levels of AKT, ERK, and JNK as well as total levels of c-MET were detected by Western blotting. IMOS-regulated genes were screened by quantitative reverse-transcription PCR (qRT-PCR) array in HCCLM3-red fluorescent protein (RFP) xenograft tissues and then confirmed by qRT-PCR in HepG2 and Hep3B cells. IMOS markedly inhibited cell proliferation and induced cell apoptosis of HCCLM3, HepG2, and Bel-7402 cells and also significantly suppressed cell adhesion, migration, and invasion of HCCLM3 in vitro. At doses of 60 and 90 mg/kg/d, IMOS displayed robust inhibitory effects on HCC growth and metastasis without obvious side effects in vivo. The levels of pERK, tERK, and pJNK as well as c-MET were significantly down-regulated after treatment with 16 mg/mL IMOS. No obvious changes were found in the levels of pAkt, tAkt, and tJNK. Ten differentially expressed genes were screened from HCCLM3-RFP xenograft tissues after treatment with IMOS at a dose of 90 mg/kg/d. Similar gene expression profiles were confirmed in HepG2 and Hep3B cells after treatment with 16 mg/mL IMOS. IMOS is a potential anti-HCC candidate through inhibition of ERK and JNK signaling independent of p53 and worth

  19. Development and Application of Multidimensional HPLC Mapping Method for O-linked Oligosaccharides

    Directory of Open Access Journals (Sweden)

    Koichi Kato

    2011-12-01

    Full Text Available Glycosylation improves the solubility and stability of proteins, contributes to the structural integrity of protein functional sites, and mediates biomolecular recognition events involved in cell-cell communications and viral infections. The first step toward understanding the molecular mechanisms underlying these carbohydrate functionalities is a detailed characterization of glycan structures. Recently developed glycomic approaches have enabled comprehensive analyses of N-glycosylation profiles in a quantitative manner. However, there are only a few reports describing detailed O-glycosylation profiles primarily because of the lack of a widespread standard method to identify O-glycan structures. Here, we developed an HPLC mapping method for detailed identification of O-glycans including neutral, sialylated, and sulfated oligosaccharides. Furthermore, using this method, we were able to quantitatively identify isomeric products from an in vitro reaction catalyzed by N-acetylglucosamine-6O-sulfotransferases and obtain O-glycosylation profiles of serum IgA as a model glycoprotein.

  20. Research Progress of Hyaluronan Oligosaccharides%透明质酸寡糖研究进展

    Institute of Scientific and Technical Information of China (English)

    崔向珍; 王凤山; 刘爱华; 郭学平

    2006-01-01

    目的综述透明质酸寡糖(oligosaccharides of hyaluronan,简称o-HA)的制备、分析方法以及其生物活性.方法查阅近年文献,进行整理归纳.结果o-HA制备时先用透明质酸酶、硫酸软骨素酶进行降解,再经阴离子交换色谱柱(ACE)等方法进行分离纯化,o-HA的生物活性有促血管生成、促进创伤愈合等.结论单糖残基数不同的o-HA生物活性可能不同;用不同酶降解产生的o-HA,即使单糖残基数相同其活性也可能不同.

  1. XYLO-OLIGOSACCHARIDES PRODUCTION BY AUTOHYDROLYSIS OF CORN FIBER SEPARATED FROM DDGS

    Directory of Open Access Journals (Sweden)

    Aditya Samala,

    2012-05-01

    Full Text Available Xylo-oligosaccharides (XOS are reported to have beneficial health properties, and they are considered to be functional food ingredients. Corn fiber separated from distillers dried grains with solubles (DDGS could be a valuable feedstock for XOS production. The objective of this study was to determine the efficacy for autohydrolysis to produce XOS using fiber separated from DDGS and to determine the optimum temperature for XOS production. Corn fiber was treated with deionized water in a Parr-reactor, at temperatures ranging from 140 to 220 °C to produce XOS. The maximum total yield of XOS in the solution was 18.6 wt% of the corn fiber at 180 °C.

  2. Effect of oligosaccharides derived from Laminaria japonica-incorporated pullulan coatings on preservation of cherry tomatoes.

    Science.gov (United States)

    Wu, Shengjun; Lu, Mingsheng; Wang, Shujun

    2016-05-15

    Laminaria japonica-derived oligosaccharides (LJOs) exhibit antibacterial and antioxidant activities, and pullulan is a food thickener that can form impermeable films. The ability of pullulan coatings with various LJO concentrations (1% pullulan+0.1%, 0.2% or 0.3% LJOs) to preserve cherry tomatoes during storage at room temperature was investigated. The LJO-incorporated pullulan coatings were found to effectively reduce respiratory intensity, vitamin C loss, weight loss and softening, as well as to increase the amount of titratable acid and the overall likeness of fruit compared with the control. These effects were observed to be dose-dependent. Therefore, using LJO-incorporated pullulan coatings can extend the shelf life of cherry tomatoes. PMID:26775974

  3. Partial characterization of the N-linked oligosaccharide structures on Pselectin glycoprotein ligand-1 (PSGL-1)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    PSGL-1,a specific ligand for P-,E- and L-selectin,was isolated from in vivo [3H]-glucosamine labeled HL-60 cells by a combination of wheat germ agglutinin-agarose and P- or E-selectin-agarose chromatography.N-linked oligosaccharides were released from the purified,denatured ligand molecule by peptide: N-glycosidase F treatment and,following separation by Sephacryl S-200 chromatography,partially characterized using lectin,ion-exchange and size-exclusion chromatography in combination with glycosidase digestions.The data obtained suggest that the N-glycans on PSGL-1 are predominantly core-fucosylated,multiantennary complex type structures with extended,poly-N-acetyllactosamine containing outer chains.A portion of the outer chains appears to be substituted with fucose indicating that the N-glycans,in addition to the O-glycans on PSGL-1,may be involved in selectin binding.

  4. Changes in glycosidase activities during galactoglucomannan oligosaccharide inhibition of auxin induced growth.

    Science.gov (United States)

    Bilisics, Ladislav; Vojtassák, Jozef; Capek, Peter; Kollárová, Karin; Lisková, Desana

    2004-07-01

    The inhibition of 2,4-D-induced elongation growth by galactoglucomannan oligosaccharides (GGMOs) in pea stem segments (Pisum sativum L. cv. Tyrkys) after 18 h of incubation results in changes of extracellular, intracellular and cell wall glycosidase activities (beta-D-glucosidase, beta-D-mannosidase, beta-D-galactosidase, beta-D-xylosidase, alpha-D-galactosidase, and alpha-L-arabinosidase). GGMOs lowered the glycosidase activities in the extracellular fraction, while in the cell wall fractions their activities were markedly increased. The intracellular enzyme alpha-d-galactosidase increased while the beta-d-galactosidase decreased in activity in response to the GGMO treatment. Extracellular enzymes showed low values of activities in comparison with intracellular and cell wall glycosidases. It is evident that GGMOs can alter auxin induced elongation and glycosidase activities in different compartments of the cell, however, the mode and site of their action remains unclear. PMID:15279996

  5. Fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) and nonallergic food intolerance: FODMAPs or food chemicals?

    Science.gov (United States)

    Barrett, Jacqueline S; Gibson, Peter R

    2012-07-01

    Food intolerance in irritable bowel syndrome (IBS) is increasingly being recognized, with patients convinced that diet plays a role in symptom induction. Evidence is building to implicate fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) in the onset of abdominal pain, bloating, wind and altered bowel habit through their fermentation and osmotic effects. Hypersensitivity to normal levels of luminal distension is known to occur in patients with IBS, with consideration of food chemical intolerance likely to answer many questions about this physiological process. This paper summarizes the evidence and application of the most common approaches to managing food intolerance in IBS: the low-FODMAP diet, the elimination diet for food chemical sensitivity and others including possible noncoeliac gluten intolerance. PMID:22778791

  6. Alterations in regulatory T cells induced by specific oligosaccharides improve vaccine responsiveness in mice.

    Directory of Open Access Journals (Sweden)

    Marcel A Schijf

    Full Text Available Prophylactic vaccinations are generally performed to protect naïve individuals with or without suppressed immune responsiveness. In a mouse model for Influenza vaccinations the specific alterations of CD4(+CD25(+Foxp3(+ regulatory T-cells (Tregs in the immune modulation induced by orally supplied oligosaccharides containing scGOS/lcFOS/pAOS was assessed. This dietary intervention increased vaccine specific DTH responses. In addition, a significant increased percentage of T-bet(+ (Th1 activated CD69(+CD4(+ T cells (p<0.001 and reduced percentage of Gata-3(+ (Th2 activated CD69(+CD4(+T cells (p<0.001 was detected in the mesenteric lymph nodes (MLN of mice receiving scGOS/lcFOS/pAOS compared to control mice. Although no difference in the number or percentage of Tregs (CD4(+Foxp3(+ could be determined after scGOS/lcFOS/pAOS intervention, the percentage of CXCR3 (+ /T-bet(+ (Th1-Tregs was significantly reduced (p<0.05 in mice receiving scGOS/lcFOS/pAOS as compared to mice receiving placebo diets. Moreover, although no absolute difference in suppressive capacity could be detected, an alteration in cytokine profile suggests a regulatory T cell shift towards a reducing Th1 suppression profile, supporting an improved vaccination response.These data are indicative for improved vaccine responsiveness due to reduced Th1 suppressive capacity in the Treg population of mice fed the oligosaccharide specific diet, showing compartmentalization within the Treg population. The modulation of Tregs to control immune responses provides an additional arm of intervention using alternative strategies possibly leading to the development of improved vaccines.

  7. Human milk oligosaccharides reduce Entamoeba histolytica attachment and cytotoxicity in vitro.

    Science.gov (United States)

    Jantscher-Krenn, Evelyn; Lauwaet, Tineke; Bliss, Laura A; Reed, Sharon L; Gillin, Frances D; Bode, Lars

    2012-11-28

    Human milk oligosaccharides (HMO), complex sugars that are highly abundant in breast milk, block viral and bacterial attachment to the infant's intestinal epithelium and lower the risk of infections. We hypothesised that HMO also prevent infections with the protozoan parasite Entamoeba histolytica, as its major virulence factor is a lectin that facilitates parasite attachment and cytotoxicity and binds galactose (Gal) and N-acetyl-galactosamine. HMO contain Gal, are only minimally digested in the small intestine and reach the colon, the site of E. histolytica infection. The objective of the present study was to investigate whether HMO reduce E. histolytica attachment and cytotoxicity. Our in vitro results show that physiological concentrations of isolated, pooled HMO detach E. histolytica by more than 80 %. In addition, HMO rescue E. histolytica-induced destruction of human intestinal epithelial HT-29 cells in a dose-dependent manner. The cytoprotective effects were structure-specific. Lacto-N-tetraose with its terminal Gal rescued up to 80 % of the HT-29 cells, while HMO with fucose α1-2-linked to the terminal Gal had no effect. Galacto-oligosaccharides (GOS), which also contain terminal Gal and are currently added to infant formula to mimic some of the beneficial effects of HMO, completely abolished E. histolytica attachment and cytotoxicity at 8 mg/ml. Although our results need to be confirmed in vivo, they may provide one explanation for why breast-fed infants are at lower risk of E. histolytica infections. HMO and GOS are heat tolerant, stable, safe and in the case of GOS, inexpensive, which could make them valuable candidates as alternative preventive and therapeutic anti-amoebic agents.

  8. Raffinose family oligosaccharide utilisation by probiotic bacteria: insight into substrate recognition, molecular architecture and diversity of GH36 alpha-galactosidases

    DEFF Research Database (Denmark)

    Abou Hachem, Maher; Fredslund, Folmer; Andersen, Joakim Mark;

    2012-01-01

    The organisation of genes conferring utilisation of raffinose family oligosaccharides (RFOs) has been analysed in several probiotic bacteria from the Bifidobacterium and Lactobacillus genera. Glycoside hydrolase family 36 (GH36) alpha-galatosidase encoding genes occur together with sugar transpor...

  9. Structural analysis of xyloglucan oligosaccharides by [sup 1]H-N. M. R. spectroscopy and fast-atom-bombardment mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    York, W.S.; Halbeek, H. van; Darvill, A.G.; Albersheim, P. (Univ. of Georgia, Athens (United States))

    1990-01-01

    A method to determine rapidly the identities and proportions of the oligosaccharide repeating-units in plant cell-wall xyloglucans by 1D [sup 1]H-N.M.R. spectroscopy was developed. Six of the most commonly found xyloglucan oligosaccharide subunits (including three subunits that had not been fully characterized previously) were prepared by endo-(I [yields] 4)-[beta]-D-glucanase digestion of xyloglucans from various plant species. The oligosaccharides were reduced to the corresponding oligoglycosyl-alditols, purified, and characterized by glycosyl composition and linkage analysis, [sup 1]H-N.M.R. spectroscopy, and f.a.b.-mass spectrometry. Correlations between the [sup 1]H-N.M.R. spectra and the structures of the oligoglycosyl-alditols can be used to identify oligoglycosyl-alditols derived from xyloglucans of unknown structure. The identities and relative amounts of the oligosaccharide subunits of xyloglucans isolated from tamarind seed and rapeseed hulls were determined on this basis.

  10. Isolation of inulin-type oligosaccharides from Chinese traditional medicine: Morinda officinalis How and their characterization using ESI-MS/MS.

    Science.gov (United States)

    Yang, Zhenmin; Yi, Yongtao; Gao, Chuanchuan; Hou, Dengke; Hu, Jun; Zhao, Mingyue

    2010-01-01

    Inulin-type oligosaccharides with different DP were prepared by size-exclusion chromatography and purity of each oligosaccharide was determined by HPLC equipped with cyclodextrin-bond column. The purities of obtained inulin-type oligosaccharides with different DP were more than 98% by one-step process. The DP and molecular weight were obtained through ESI-MS in negative mode. The characterization of the inulin-type oligosaccharides with different DP was studied by MS/MS spectra obtained by collision-induced dissociation of molecular ions ([M-H](-)). When the DP was lower, the fragment ions were formed through cross-ring cleavages of two bonds within the sugar ring and glycosidic cleavages. However, with the increase of DP, the ions resulting from glycosidic cleavages between two sugar residues were predominant. PMID:20091714

  11. Ingestion of a novel galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex affected growth performance and fermentative and immunological characteristics of broiler chicks challenged with Salmonella typhimurium

    Science.gov (United States)

    Fermentable carbohydrates may enhance the ability of the gastrointestinal tract to defend against a pathogenic infection. We hypothesized that a galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex would positively impact immune status and prevent colonization and shedding in Salmonell...

  12. Synthesis and structural characterization of raffinosyl-oligofructosides upon transfructosylation by Lactobacillus gasseri DSM 20604 inulosucrase.

    Science.gov (United States)

    Díez-Municio, Marina; Herrero, Miguel; de Las Rivas, Blanca; Muñoz, Rosario; Jimeno, M Luisa; Moreno, F Javier

    2016-07-01

    A new process based on enzymatic synthesis of a series of raffinose-derived oligosaccharides or raffinosyl-oligofructosides (RFOS) with degree of polymerization (DP) from 4 to 8 was developed in the presence of raffinose. This process involves a transfructosylation reaction catalyzed by an inulosucrase from Lactobacillus gasseri DSM 20604 (IS). The main synthesized RFOS were structurally characterized by nuclear magnetic resonance (NMR). According to the elucidated structures, RFOS consist of β-2,1-linked fructose unit(s) to raffinose: α-D-galactopyranosyl-(1 → 6)-α-D-glucopyranosyl-(1↔2)-β-D-fructofuranosyl-((1 ← 2)-β-D-fructofuranoside)n (where n refers to the number of transferred fructose moieties). The maximum yield of RFOS was 33.4 % (in weight respect to the initial amount of raffinose) and was obtained at the time interval of 8-24 h of transfructosylation reaction initiated with 50 % (w/v) of raffinose. Results revealed the high acceptor and donor affinity of IS towards raffinose, being fairly comparable with that of sucrose for the production of fructooligosaccharides (FOS), including when both carbohydrates coexisted (sucrose/raffinose mixture, 250 g L(-1) each). The production of RFOS was also attempted in the presence of sucrose/melibiose mixtures; in this case, the predominant acceptor-product formed was raffinose followed by a minor production of a series of oligosaccharides with varying DP. The easiness of RFOS synthesis and the structural similarities with both raffinose and fructan series of oligosaccharides warrant the further study of the potential bioactive properties of these unexplored oligosaccharides. PMID:26940051

  13. Comparison of Yacon (Smallanthus sonchifolius) Tuber with Commercialized Fructo-oligosaccharides (FOS) in Terms of Physiology, Fermentation Products and Intestinal Microbial Communities in Rats

    OpenAIRE

    UTAMI, Ni Wayan Arya; Sone, Teruo; Tanaka, Michiko; Nakatsu, Cindy H.; SAITO, Akihiko; Asano, Kozo

    2013-01-01

    The yacon (Smallanthus sonchifolius) tuber was examined with regard to its prebiotic effects compared with commercialized fructo-oligosaccharides (FOS). A feed containing 10% yacon tuber, which is equivalent to 5% commercialized FOS in terms of the amount of fructo-oligosaccharides (GF2, GF3 and GF4), was administrated to rats for 28 days. The yacon diet changed the intestinal microbial communities beginning in the first week, resulting in a twofold greater concentration of cecal short-chain ...

  14. Combinational effects of prebiotic oligosaccharides on bifidobacterial growth and host gene expression in a simplified mixed culture model and neonatal mice.

    Science.gov (United States)

    Ehara, Tatsuya; Izumi, Hirohisa; Tsuda, Muneya; Nakazato, Yuki; Iwamoto, Hiroshi; Namba, Kazuyoshi; Takeda, Yasuhiro

    2016-07-01

    It is important to provide formula-fed infants with a bifidobacteria-enriched gut microbiota similar to those of breastfed infants to ensure intestinal health. Prebiotics, such as certain oligosaccharides, are a useful solution to this problem, but the combinational benefits of these oligosaccharides have not been evaluated. This study investigated the benefits of oligosaccharide combinations and screened for an optimal combination of oligosaccharides to promote healthy gut microbiota of formula-fed infants. In vitro and in vivo experiments were performed to assess the bifidogenic effects of lactulose (LAC) alone and LAC combined with raffinose (RAF) and/or galacto-oligosaccharide (GOS), using a mixed culture model and neonatal mice orally administered with these oligosaccharides and Bifidobacterium breve. In the in vitro culture model, the combination of the three oligosaccharides (LAC-RAF-GOS) significantly increased cell numbers of B. breve and Bifidobacterium longum (P<0·05) compared with either LAC alone or the combination of two oligosaccharides, and resulted in the production of SCFA under anaerobic conditions. In the in vivo experiment, the LAC-RAF-GOS combination significantly increased cell numbers of B. breve and Bacteroidetes in the large intestinal content (P<0·05) and increased acetate concentrations in the caecal content and serum of neonatal mice. Genes related to metabolism and immune responses were differentially expressed in the liver and large intestine of mice administered with LAC-RAF-GOS. These results indicate a synergistic effect of the LAC-RAF-GOS combination on the growth of bifidobacteria and reveal possible benefits of this combination to the gut microbiota and health of infants. PMID:27198516

  15. Molecular Weight Dependent Glucose Lowering Effect of Low Molecular Weight Chitosan Oligosaccharide (GO2KA1) on Postprandial Blood Glucose Level in SD Rats Model

    OpenAIRE

    Emmanouil Apostolidis; Young-Cheul Kim; Chen-Gum Oh; Jong-Gwan Kim; Kyoung-Sik Moon; Kyoung-Soo Ha; Sung-Hoon Jo; Young-In Kwon

    2013-01-01

    This research investigated the effect of enzymatically digested low molecular weight (MW) chitosan oligosaccharide on type 2 diabetes prevention. Three different chitosan oligosaccharide samples with varying MW were evaluated in vitro for inhibition of rat small intestinal α-glucosidase and porcine pancreatic α-amylase (GO2KA1; 10,000 Da). The in vitro results showed that all tested samples had similar rat α-glucosidase inhibitory and porcine α-amylase inhibitory activity. Based on these obs...

  16. NMR experiments for the measurement of proton-proton and carbon-carbon residual dipolar couplings in uniformly labelled oligosaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Pastor, Manuel [Universidad de Santiago de Compostela, Laboratorio Integral de Estructura de Biomoleculas Jose. R. Carracido, Unidade de Resonancia Magnetica, RIAIDT (Spain)], E-mail: mmartin@usc.es; Canales-Mayordomo, Angeles; Jimenez-Barbero, Jesus [Departamento de Estructura y funcion de proteinas, Centro de Investigaciones Biologicas, CSIC (Spain)], E-mail: jjbarbero@cib.csic.es

    2003-08-15

    A 2D-HSQC-carbon selective/proton selective-constant time COSY, 2D-HSQC-(sel C, sel H)-CT COSY experiment, which is applicable to uniformly {sup 13}C isotopically enriched samples (U-{sup 13}C) of oligosaccharides or oligonucleotides is proposed for the measurement of proton-proton RDC in crowded regions of 2D-spectra. In addition, a heteronuclear constant time-COSY experiment, {sup 13}C-{sup 13}C CT-COSY, is proposed for the measurement of one bond carbon-carbon RDC in these molecules. These two methods provide an extension, to U-{sup 13}C molecules, of the original homonuclear constant time-COSY experiment proposed by Tian et al. (1999) for saccharides. The combination of a number of these RDC with NOE data may provide the method of choice to study oligosaccharide conformation in the free and receptor-bound state.

  17. Characterization of a heterodimeric GH2 β-galactosidase from Lactobacillus sakei Lb790 and formation of prebiotic galacto-oligosaccharides.

    Science.gov (United States)

    Iqbal, Sanaullah; Nguyen, Thu-Ha; Nguyen, Hoang Anh; Nguyen, Tien Thanh; Maischberger, Thomas; Kittl, Roman; Haltrich, Dietmar

    2011-04-27

    The lacLM genes from Lactobacillus sakei Lb790, encoding a heterodimeric β-galactosidase that belongs to glycoside hydrolase family GH2, were cloned and heterologously expressed in Escherichia coli . Subsequently, the recombinant β-galactosidase LacLM was purified to apparent homogeneity and characterized. The enzyme is a β-galactosidase with narrow substrate specificity because o-nitrophenyl-β-D-galactopyranoside (oNPG) was efficiently hydrolyzed, whereas various structurally related oNP analogues were not. The K(m) and k(cat) values for oNPG and lactose were 0.6 mM and 180 s(-1) and 20 mM and 43 s(-1), respectively. The enzyme is inhibited competitively by its two end-products D-galactose and D-glucose (K(i) values of 180 and 475 mM, respectively). As judged by the ratio of the inhibition constant to the Michaelis constant, K(i)/K(m), this inhibition is only very moderate and much less pronounced than for other microbial β-galactosidases. β-Galactosidase from L. sakei possesses high transgalactosylation activity and was used for the synthesis of galacto-oligosaccharides (GalOS), employing lactose at a concentration of 215 g/L. The maximum GalOS yield was 41% (w/w) of total sugars at 77% lactose conversion and contained mainly non-lactose disaccharides, trisaccharides, and tetrasaccharides with approximately 38, 57, and 5% of total GalOS formed, respectively. The enzyme showed a strong preference for the formation of β-(1→6)-linked transgalactosylation products, whereas β-(1→3)-linked compounds were formed to a lesser extent and β-(1→4)-linked reaction products could not be detected. PMID:21405014

  18. Total synthesis of the α-subunit of human glycoprotein hormones: toward fully synthetic homogeneous human follicle-stimulating hormone.

    Science.gov (United States)

    Aussedat, Baptiste; Fasching, Bernhard; Johnston, Eric; Sane, Neeraj; Nagorny, Pavel; Danishefsky, Samuel J

    2012-02-22

    Described herein is the first total chemical synthesis of the unique α-subunit of the human glycoprotein hormone (α-hGPH). Unlike the biologically derived glycoprotein hormones, which are isolated as highly complex mixtures of glycoforms, α-hGPH obtained by chemical synthesis contains discrete homogeneous glycoforms. Two such systems have been prepared. One contains the disaccharide chitobiose at the natural N-glycosylation sites. The other contains dodecamer oligosaccharides at these same sites. The dodecamer sugar is a consensus sequence incorporating the key features associated with human glycoproteins.

  19. Isolation and characterization of an agaro-oligosaccharide (AO-hydrolyzing bacterium from the gut microflora of Chinese individuals.

    Directory of Open Access Journals (Sweden)

    Miaomiao Li

    Full Text Available Agarose (AP from red algae has a long history as food ingredients in East Asia. Agaro-oligosaccharides (AO derived from AP have shown potential prebiotic effects. However, the human gut microbes responsible for the degradation of AO and AP have not yet been fully investigated. Here, we reported that AO and AP can be degraded and utilized at various rates by fecal microbiota obtained from different individuals. Bacteroides uniformis L8 isolated from human feces showed a pronounced ability to degrade AO and generate D-galactose as its final end product. PCR-DGGE analysis showed B. uniformis to be common in the fecal samples, but only B. uniformis L8 had the ability to degrade AO. A synergistic strain, here classified as Escherichia coli B2, was also identified because it could utilize the D-galactose as the growth substrate. The cross-feeding interaction between B. uniformis L8 and E. coli B2 led to exhaustion of the AO supply. Bifidobacterium infantis and Bifidobacterium adolescentis can utilize one of the intermediates of AO hydrolysis, agarotriose. Growth curves indicated that AO was the substrate that most favorably sustained the growth of B. uniformis L8. In contrast, κ-carrageenan oligosaccharides (KCO, guluronic acid oligosaccharides (GO, and mannuronic acid oligosaccharides (MO were found to be unusable to B. uniformis L8. Current results indicate that B. uniformis L8 is a special degrader of AO in the gut microbiota. Because B. uniformis can mitigate high-fat-diet-induced metabolic disorders, further study is required to determine the potential applications of AO.

  20. High performance liquid chromatography (HPLC) applied to determination of oligosaccharides in irradiated beans (Vigna unguiculata (L.) Walp)

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Keila S. Cople; Souza, Luciana B.; Coelho, Maysa J.; Lima, Antonio L. Santos; Vital, Helio C. [Instituto Militar de Engenharia IME, Rio de Janeiro, RJ (Brazil). Secao de Engenharia Nuclear]. E-mail: keila@ime.eb.br; maysa@ime.eb.br; santoslima@ime.eb.br; Godoy, Ronoel L.O. [EMBRAPA Agroindustria de Alimentos, Rio de Janeiro, RJ (Brazil)]. E-mail: ronoel@ctaa.embrapa.br

    2007-07-01

    Beans are important components of Brazilian diet, especially for less affordable people. They have in their composition proteins, vitamins, carbohydrates, minerals and fibers. Despite of their high nutritional value, nonnutritive elements from natural origin are present in leguminous plants, such as raffinose and stachyose. The oligosaccharides are flatulence agents due to bacterial anaerobic fermentation at the intestines. The aim of this study is to evaluate the effect of combined boiling and gamma irradiation treatments on fradinho-beans (Vigna unguiculata (L.) Walp) with respect to oligosaccharide contents. The irradiation process was performed at the Nuclear Defense Section of Brazilian Army, using a cavity type research irradiator, which has a Cs-137 radiation source and maximum dose rate of 1.8 kGy/h. The oligosaccharides were evaluated by HPLC technique, at 'EMBRAPA Agroindustria de Alimentos', using a SHIMADZU liquid chromatography system, with a refraction index detector Waters 2421. The mobile phase was acetonitrile 70% in water for raffinose and stachyose and 80% for saccharose. The flux and the running time were 1 mL/min and 18 minutes for raffinose and stachyose, and 1.3 mL/min and 20 minutes for saccharose. The injection volume was 20 {mu}L and the column used (Waters 250 x 4,6 mm; 4 mm) was kept at room temperature. The evaluation of unboiled irradiated beans showed that there was no significant difference between the different irradiation doses and control sample, keeping the oligosaccharide contents. However, the combination of the boiling and the irradiation processes turned out to reduce of non-nutritive factors that may cause flatulence, meaning a real benefit to the consumers. (author)

  1. Survival and synergistic growth of mixed cultures of bifidobacteria and lactobacilli combined with prebiotic oligosaccharides in a gastrointestinal tract simulator.

    OpenAIRE

    Adamberg, Signe; Sumeri, Ingrid; Uusna, Riin; Ambalam, Padma; Kondepudi, Kanthi Kiran; Adamberg, Kaarel; Wadström, Torkel; Ljungh, Åsa

    2014-01-01

    Background: Probiotics, especially in combination with non-digestible oligosaccharides, may balance the gut microflora while multistrain preparations may express an improved functionality over single strain cultures. In vitro gastrointestinal models enable to test survival and growth dynamics of mixed strain probiotics in a controlled, replicable manner.Methods: The robustness and compatibility of multistrain probiotics composed of bifidobacteria and lactobacilli combined with mixed prebiotic...

  2. Prebiotic xylo-oligosaccharides as high-value co-products on an integrated biorefinery approach from lignocellulosic feedstock

    OpenAIRE

    Moura, Patrícia; Carvalheiro, Florbela; Esteves, M. P.; Gírio, Francisco M.

    2008-01-01

    The present work proposes the production of prebiotic xylo-oligosaccharides (XOS) as high-value co-products of the Lignocellulose Feedstock Biorefinery concept, foreseeing potential applications on food, feed and nutraceutical industries. Autohydrolysis was used to selectively solubilise the hemicellulosic fraction of several xylan-rich, widely available, agricultural, agro-industrial and forestry by-products: corn cobs, brewery’s spent grain and Eucalyptus wood chips. The soluble hemicellulo...

  3. Structural diversity of the lipid A and core oligosaccharide moieties of the lipopolysaccharides from nontypeable and serotype f Haemophilus influenzae

    OpenAIRE

    Yildirim, Håkan

    2005-01-01

    This thesis describes structural studies of the oligosaccharide and lipid A moieties of lipopolysaccharides (LPSs) isolated from disease-causing Haemophilus influenzae strains. The nontypeable strains were clinical isolates from the middle ear of children suffering from otitis media and the serotype f strains had been collected from three adults with respiratory tract infections. The LPS molecules are situated on the cell wall of H. influenzae strains and they play a ver...

  4. Polydextrose, Lactitol, and Fructo-Oligosaccharide Fermentation by Colonic Bacteria in a Three-Stage Continuous Culture System

    OpenAIRE

    Probert, Hollie M.; Apajalahti, Juha H. A.; Rautonen, Nina; Stowell, Julian; Glenn R Gibson

    2004-01-01

    In vitro fermentations were carried out by using a model of the human colon to simulate microbial activities of lower gut bacteria. Bacterial populations (and their metabolic products) were evaluated under the effects of various fermentable substrates. Carbohydrates tested were polydextrose, lactitol, and fructo-oligosaccharide (FOS). Bacterial groups of interest were evaluated by fluorescence in situ hybridization as well as by species-specific PCR to determine bifidobacterial species and pe...

  5. Utilization of Natural Fucosylated Oligosaccharides by Three Novel α-l-Fucosidases from a Probiotic Lactobacillus casei Strain ▿

    Science.gov (United States)

    Rodríguez-Díaz, Jesús; Monedero, Vicente; Yebra, María J.

    2011-01-01

    Three putative α-l-fucosidases encoded in the Lactobacillus casei BL23 genome were cloned and purified. The proteins displayed different abilities to hydrolyze natural fucosyloligosaccharides like 2′-fucosyllactose, H antigen disaccharide, H antigen type II trisaccharide, and 3′-, 4′-, and 6′-fucosyl-GlcNAc. This indicated a possible role in the utilization of oligosaccharides present in human milk and intestinal mucosa. PMID:21097595

  6. Capillary Zone Electrophoresis Investigation of Interactions between Granulocyte-colony Stimulating Factor and Dextran Sulfate / Carrageenan Oligosaccharide

    Institute of Scientific and Technical Information of China (English)

    Ai Ye LIANG; Yu Guang DU; Ke Yi WANG; Bing Cheng LIN

    2005-01-01

    The interactions between granulocyte-colony stimulating factor (G-CSF) and dextran sulfate / κ-carrageenan oligosa1ccharide were studied by capillary zone electrophoresis. Dextran sulfate could strongly interact with G-CSF and the complex was detected. The binding constant and stoichiometry were determined to be 1.2x106 (mol/L)-1 and 3:1, respectively. However, the interaction between κ-carrageenan oligosaccharide and G-CSF was not found.

  7. Enhancement of Diosgenin Production in Dioscorea zingiberensis Cell Cultures by Oligosaccharides from Its Endophytic Fungus Fusarium oxysporum Dzf17

    Directory of Open Access Journals (Sweden)

    Ligang Zhou

    2011-12-01

    Full Text Available The effects of the oligosaccharides from the endophytic fungus Fusarium oxysporum Dzf17 as elicitors on diosgenin production in cell suspension cultures of its host Dioscorea zingiberensis were investigated. Three oligosaccharides, DP4, DP7 and DP10, were purified from the oligosaccharide fractions DP2-5, DP5-8 and DP8-12, respectively, which were prepared from the water-extracted mycelial polysaccharide of the endophytic fungus F. oxysporum Dzf17. When the cell cultures were treated with fraction DP5-8 at 20 mg/L on day 26 and harvested on day 32, the maximum diosgenin yield (2.187 mg/L was achieved, which was 5.65-fold of control (0.387 mg/L. When oligosaccharides DP4, DP7 and DP10 were individually added to 26-day-old D. zingiberensis cell cultures at concentrations of 2, 4, 6, 8 and 10 mg/L in medium, DP7 at 6 mg/L was found to significantly enhance diosgenin production, with a yield of 3.202 mg/L, which was 8.27-fold of control. When the cell cultures were treated with DP7 twice on days 24 and 26, and harvested on day 30, both diosgenin content and yield were significantly increased and reached the maximums of 1.159 mg/g dw and 4.843 mg/L, both of which were higher than those of single elicitation, and were 9.19- and 12.38-fold of control, respectively.

  8. Prebiotic oligosaccharides change the concentrations of short-chain fatty acids and the microbial population of mouse bowel*

    OpenAIRE

    Pan, Xiao-dong; Chen, Fen-qin; Wu, Tian-xing; Tang, Hong-gang; Zhao, Zhan-yu

    2009-01-01

    The purpose of this study was to clarify effects of selected oligosaccharides on concentrations of cecal short-chain fatty acids (SCFAs), total large bowel wet weight and wall weight, and cecal microbiota levels in mice. Mice were respectively given gavage of selected fructooligosaccharides (FOS), galactooligosaccharides (GOS), mannanoligosaccharides (MOS), and chitooligosaccharides (COS) [1000 mg/(kg body weight·d)]. Control group was given physiological saline solution. After 14 d treatment...

  9. Increased sialylation of oligosaccharides on IgG paraproteins--a potential new tumour marker in multiple myeloma.

    OpenAIRE

    Fleming, S C; Smith, S.; Knowles, D; Skillen, A.; Self, C H

    1998-01-01

    AIMS: To investigate whether changes in carbohydrate structure of IgG are related to malignancy and stage of disease in myeloma and monoclonal gammopathy of uncertain significance (MGUS). METHODS: 61 patients were studied at diagnosis: 14 with MGUS, nine with stage I multiple myeloma, 11 with stage II, 21 with stage III, and five with solitary plasmacytoma. IgG was extracted from serum by protein G affinity chromatography. Oligosaccharides were cleaved from the protein backbone enzymatically ...

  10. Gluco-oligomers initially formed by the reuteransucrase enzyme of Lactobacillus reuteri 121 incubated with sucrose and malto-oligosaccharides

    OpenAIRE

    Dobruchowska, J. M.; X. Meng; Leemhuis, H.; Gerwig, G J; Dijkhuizen, L.; Kamerling, J P

    2013-01-01

    The probiotic bacterium Lactobacillus reuteri 121 produces a complex, branched (1 -> 4, 1 -> 6)-alpha-d-glucan as extracellular polysaccharide (reuteran) from sucrose (Suc), using a single glucansucrase/glucosyltransferase (GTFA) enzyme (reuteransucrase). To gain insight into the reaction/product specificity of the GTFA enzyme and the mechanism of reuteran formation, incubations with Suc and/or a series of malto-oligosaccharides (MOSs) (degree of polymerization (DP2-DP6)) were followed in tim...

  11. Gluco-oligomers initially formed by the reuteransucrase enzyme of Lactobacillus reuteri 121 incubated with sucrose and malto-oligosaccharides.

    Science.gov (United States)

    Dobruchowska, Justyna M; Meng, Xiangfeng; Leemhuis, Hans; Gerwig, Gerrit J; Dijkhuizen, Lubbert; Kamerling, Johannis P

    2013-09-01

    The probiotic bacterium Lactobacillus reuteri 121 produces a complex, branched (1 → 4, 1 → 6)-α-D-glucan as extracellular polysaccharide (reuteran) from sucrose (Suc), using a single glucansucrase/glucosyltransferase (GTFA) enzyme (reuteransucrase). To gain insight into the reaction/product specificity of the GTFA enzyme and the mechanism of reuteran formation, incubations with Suc and/or a series of malto-oligosaccharides (MOSs) (degree of polymerization (DP2-DP6)) were followed in time. The structures of the initially formed products, isolated via high-performance anion-exchange chromatography, were analyzed by matrix-assisted laser-desorption ionization time-of-flight mass spectrometry and 1D/2D (1)H/(13)C NMR spectroscopy. Incubations with Suc only, acting as both donor and acceptor, resulted in elongation of Suc with glucose (Glc) units via alternating (α1 → 4) and (α1 → 6) linkages, yielding linear gluco-oligosaccharides up to at least DP ~ 12. Simultaneously with the ensemble of oligosaccharides, polymeric material was formed early on, suggesting that alternan fragments longer than DP ~ 12 have higher affinity with the GTFA enzyme and are quickly extended, yielding high-molecular-mass branched reuteran (4 × 10(7) Da). MOSs (DP2-DP6) in the absence of Suc turned out to be poor substrates. Incubations of GTFA with Suc plus MOSs as substrates resulted in preferential elongation of MOSs (acceptors) with Glc units from Suc (donor). This apparently reflects the higher affinity of GTFA for MOSs compared with Suc. In accordance with the GTFA specificity, most prominent products were oligosaccharides with an (α1 → 4)/(α1 → 6) alternating structure. PMID:23804502

  12. Effect of supplementation of Manno-Oligosaccharide and b-glucans on maize based meal on commercial broilers

    Directory of Open Access Journals (Sweden)

    R.C.Shendare

    2008-01-01

    Full Text Available A study with 200 vencobb broilers was carried out to compare the effect of the use of Manno-Oligosaccharide and b-glucans of Saccharomyces cerevisiae cell wall or growth promoter ( AGRIMOS and reg; feed in the diet @ 1Kg /ton of feed to the broiler. Diets were based on maize meal. A completely randomized experimental design was used, and the obtained data were evaluated by analysis. The following parameters were measured: feed intake, daily weight gain, feed conversion ratio, and mortality. After 6 weeks of fattening, the average live weight of broilers in the experimental group was 1821.11g, while the average live weight of broilers in control group was 1712.22g (P<0.01. Supplementation of Manno-Oligosaccharide and b-glucans preparation influence the achievement of higher live weights of broilers from the experimental group ( 5.37% , compared to the control and enhanced feed conversion ( 8.45 % . It was concluded that the effect of the inclusion of Manno-Oligosaccharide and b-glucans in the diet shows significantly higher body weight gain and improvement in feed efficiency as compared to the control diet. [Vet World 2008; 1(1.000: 13-15

  13. Qualitative and quantitative analysis of seven oligosaccharides in Morinda officinalis using double-development HPTLC and scanning densitometry.

    Science.gov (United States)

    Zhou, Bin; Chang, Jun; Wang, Ping; Li, Jie; Cheng, Dan; Zheng, Peng-Wu

    2014-01-01

    The quality of Morindaofficinalis, which has been used as a Yang-tonic agent for a long time in China, can be evaluated. A double-development high performance thin layer chromatography (HPTLC) method has been established to simultaneously analyze quality and quantity of seven inulin-type oligosaccharides (DP=3-9) in Morindaofficinalis. The chromatography was performed on a silica gel 60 plate with the 7:5:2:1 proportion (v/v) of n-butanol-isopropanol-water-acetic acid for the first and second developments, respectively. The bands were visualized by the reaction with aniline-diphenylamine-phosphoric acid solution and analyzed by densitometric TLC at 540 nm. Quantification of seven oligosaccharides was achieved by densitometry at 540 nm. The investigated standard sugar had good linearity (R2>0.99) within test ranges. The amounts of seven oligosaccharides were calculated by the relative correction factor (RCF). Therefore, the developed TLC method could be used for quality control of Morindaofficinalis. PMID:24211984

  14. Heat treatment of curdlan enhances the enzymatic production of biologically active β-(1,3)-glucan oligosaccharides.

    Science.gov (United States)

    Kumagai, Yuya; Okuyama, Masayuki; Kimura, Atsuo

    2016-08-01

    Biologically active β-(1,3)-glucan oligosaccharides were prepared from curdlan using GH64 enzyme (KfGH64). KfGH64 showed low activity toward native curdlan; thereby pretreatment conditions of curdlan were evaluated. KfGH64 showed the highest activity toward curdlan with heat treatment. The most efficient pretreatment (90°C for 0.5h) converted approximately 60% of curdlan into soluble saccharides under the optimized enzyme reaction conditions (pH 5.5, 37°C, 100rpm mixing speed, 24h, and 10μg of KfGH64/1g of curdlan). The resulting products were predominantly laminaripentaose and a small amount of β-(1,3)-glucans with an average degree of polymerization (DP) of 13 and 130. The products did not contain small oligosaccharides (DPhydrolysis of heat-treated curdlan by KfGH64 is a suitable method for the production of biologically active β-(1,3)-glucan oligosaccharides. PMID:27112889

  15. HABA-based ionic liquid matrices for UV-MALDI-MS analysis of heparin and heparan sulfate oligosaccharides.

    Science.gov (United States)

    Przybylski, Cedric; Gonnet, Florence; Bonnaffé, David; Hersant, Yael; Lortat-Jacob, Hugues; Daniel, Regis

    2010-02-01

    Polysulfated carbohydrates such as heparin (HP) and heparan sulfate (HS) are not easily amenable to usual ultraviolet matrix-assisted laser desorption/ionization-mass spectrometry (UV-MALDI)-MS analysis due to the thermal lability of their O- and N-SO(3) moieties, and their poor ionization efficiency with common crystalline matrices. Recently, ionic liquid matrices showed considerable advantages over conventional matrices for MALDI-MS of acidic compounds. Two new ionic liquid matrices (ILMs) based on the combination of 2-(4-hydroxyphenylazo)benzoic acid (HABA) with 1,1,3,3-tetramethylguanidine and spermine were evaluated in the study herein. Both ILMs were successfully applied to the analysis of synthetic heparin oligosaccharides of well-characterized structures as well as to heparan sulfate-derived oligosaccharides from enzymatic depolymerization. HABA-based ILMs showed improved signal-to-noise ratio as well as a decrease of fragmentation/desulfation processes and cation exchange. Sulfated oligosaccharides were detected with higher sensitivity than usual crystalline matrices, and their intact fully O- and N-sulfated species [M-Na](-) were easily observed on mass spectra. MALDI-MS characterization of challenging analytes such as heparin octasaccharide carrying 8-O and 4 N-sulfo groups, and heparin octadecasulfated dodecasaccharide was successfully achieved.

  16. Identification of yeast genes that confer resistance to chitosan oligosaccharide (COS using chemogenomics

    Directory of Open Access Journals (Sweden)

    Jaime Maria DLA

    2012-06-01

    Full Text Available Abstract Background Chitosan oligosaccharide (COS, a deacetylated derivative of chitin, is an abundant, and renewable natural polymer. COS has higher antimicrobial properties than chitosan and is presumed to act by disrupting/permeabilizing the cell membranes of bacteria, yeast and fungi. COS is relatively non-toxic to mammals. By identifying the molecular and genetic targets of COS, we hope to gain a better understanding of the antifungal mode of action of COS. Results Three different chemogenomic fitness assays, haploinsufficiency (HIP, homozygous deletion (HOP, and multicopy suppression (MSP profiling were combined with a transcriptomic analysis to gain insight in to the mode of action and mechanisms of resistance to chitosan oligosaccharides. The fitness assays identified 39 yeast deletion strains sensitive to COS and 21 suppressors of COS sensitivity. The genes identified are involved in processes such as RNA biology (transcription, translation and regulatory mechanisms, membrane functions (e.g. signalling, transport and targeting, membrane structural components, cell division, and proteasome processes. The transcriptomes of control wild type and 5 suppressor strains overexpressing ARL1, BCK2, ERG24, MSG5, or RBA50, were analyzed in the presence and absence of COS. Some of the up-regulated transcripts in the suppressor overexpressing strains exposed to COS included genes involved in transcription, cell cycle, stress response and the Ras signal transduction pathway. Down-regulated transcripts included those encoding protein folding components and respiratory chain proteins. The COS-induced transcriptional response is distinct from previously described environmental stress responses (i.e. thermal, salt, osmotic and oxidative stress and pre-treatment with these well characterized environmental stressors provided little or any resistance to COS. Conclusions Overexpression of the ARL1 gene, a member of the Ras superfamily that regulates membrane

  17. Determining the isomeric heterogeneity of neutral oligosaccharide-alditols of bovine submaxillary mucin using negative ion traveling wave ion mobility mass spectrometry.

    Science.gov (United States)

    Li, Hongli; Bendiak, Brad; Siems, William F; Gang, David R; Hill, Herbert H

    2015-02-17

    Negative ions produced by electrospray ionization were used to evaluate the isomeric heterogeneity of neutral oligosaccharide-alditols isolated from bovine submaxillary mucin (BSM). The oligosaccharide-alditol mixture was preseparated on an off-line high-performance liquid chromatography (HPLC) column, and the structural homogeneity of individual LC fractions was investigated using a Synapt G2 traveling wave ion mobility spectrometer coupled between quadupole and time-of-flight mass spectrometers. Mixtures of isomers separated by both chromatography and ion mobility spectrometry were studied. Tandem mass spectrometry (MS/MS) of multiple mobility peaks having the same mass-to-charge ratio (m/z) demonstrated the presence of different structural isomers and not differences in ion conformations due to charge site location. Although the oligosaccharide-alditol mixture was originally separated by HPLC, multiple ion mobility peaks due to structural isomers were observed for a number of oligosaccharide-alditols from single LC fractions. The collision-induced dissociation cells located in front of and after the ion mobility separation device enabled oligosaccharide precursor or product ions to be separated by ion mobility and independent fragmentation spectra to be acquired for isomeric carbohydrate precursor or product ions. MS/MS spectra so obtained for independent mobility peaks at a single m/z demonstrated the presence of structural variants or stereochemical isomers having the same molecular formula. This was observed both for oligosaccharide precursor and product ions. In addition, mobilities of both [M - H](-) and [M + Cl](-) ions, formed by adding NH4OH or NH4Cl to the electrospray solvent, were examined and compared for selected oligosaccharide-alditols. Better separation among structural isomers appeared to be achieved for some [M + Cl](-) anions.

  18. Structural modulation of gut microbiota by chondroitin sulfate and its oligosaccharide.

    Science.gov (United States)

    Shang, Qingsen; Shi, Jingjing; Song, Guanrui; Zhang, Meifang; Cai, Chao; Hao, Jiejie; Li, Guoyun; Yu, Guangli

    2016-08-01

    Chondroitin sulfate (CS) as a dietary supplement and a symptomatic slow acting (SYSA) drug has been used for years. Recently, CS has been demonstrated to be readily degraded and fermented in vitro by specific human gut microbes, hinting that dietary CS may pose a potential effect on gut microbiota composition in vivo. However, until now, little information is available on modulations of gut microbiota by CS. In the present study, modulations of gut microbiota in Kunming mice by CS and its oligosaccharide (CSO) were investigated by high-throughput sequencing. As evidenced by Heatmap and principal component analysis (PCA), the female microbiota were more vulnerable than the male microbiota to CS and CSO treatment. Besides, it is of interest to found that CS and CSO had differing effects on the abundance of Bacteroidales S24-7, Bacteroides, Helicobacter, Odoribacter, Prevotellaceae and Lactobacillus in male mice versus female mice. Collectively, we demonstrated a sex-dependent effect on gut microbiota of CS and CSO. In addition, since gut microbiota exerts a major effect on host physiology, our study highlighted that certain beneficial effects of CS may be associated with modulations of gut microbiota, which merits further investigation. PMID:27164502

  19. Effectiveness of dietary xylo-oligosaccharides for broilers fed a conventional corn-soybean meal diet

    Institute of Scientific and Technical Information of China (English)

    SUO Hai-qing; LU Lin; XU Guo-hui; XIAO Lin; CHEN Xiao-gang; XIA Rui-rui; ZHANG Li-yang; LUO Xu-gang

    2015-01-01

    An experiment was conducted to investigate the effect of dietary supplementation of xylo-oligosaccharides (XOS) on growth performance, meat quality, immune functions, duodenal morphology and intestinal microbial populations of broilers fed a conventional corn-soybean meal basal diet. A total of 450 1-day-old commercial Arbor Acres male broiler chicks were ran-domly alocated by bodyweight to 1 of 5 treatments with 6 replicate cages (15 broilers per cage) for each of 5 treatments in a completely randomized design. Chicks were fed the basal corn-soybean meal diets supplemented with 0, 25, 50, 75, or 100 mg of XOS kg–1 of diet, respectively, for an experimental duration of 42 days. The results showed that supple-mentation of XOS affected feed conversion rate (feed/gain, F/G) during days 22–42 and 1–42 (P0.05) on al other measured indices. The chicks fed the diet supplemented with 100 mg of XOS kg–1 had the lowest (P<0.05) F/G and drip loss in thigh muscle. The drip loss in thigh muscle decreased linearly (P=0.003) as the supplemented XOS increased. Duodenal crypt depth decreased (P<0.05) at the supplemental level of 75 mg of XOS kg–1. The results indicate that dietary supplementations of 75 and 100 mg of XOS kg–1 are beneifcial to broilers fed a conventional corn-soybean meal diet.

  20. Studies on production of fructo-oligosaccharides (FOS) by gamma radiation processing of microbial levan.

    Science.gov (United States)

    Jalan, N; Varshney, Lalit; Misra, Nilanjal; Paul, Jhimli; Mitra, D; Rairakhwada, D D; Bhathena, Z; Kumar, Virendra

    2013-07-01

    Microbial levan, a natural polymer of fructose, was produced and purified by alcohol precipitation from culture supernatants of Bacillus megaterium type 1 grown in an optimized liquid sucrose medium. GPC analysis showed that the yield of the major fraction of levan having molecular weight ~5000 D increased with increase in sucrose concentration in the broth. Levan subjected to (60)Co-gamma radiation as well as acid hydrolysis was investigated by rheometry, UV-visible spectrophotometry and gel permeation chromatography (GPC) techniques. Unlike most of the polysaccharides, levan powder exhibited good radiation degradation stability up to 150 kGy. Gamma irradiation of 10% levan aqueous solution at 250 kGy yielded 63.0% fructo-oligosaccharide (FOS) with an average molecular weight of 1250 D. Acid hydrolysis of levan using 0.5 N HCl for 60 min treatment time gave rise to the desired FOS with lower yield (23.1%) as compared to that obtained in gamma radiolysis process. PMID:23688493

  1. Characterisation of separated end hyaluronan oligosaccharides from leech hyaluronidase and evaluation of angiogenesis.

    Science.gov (United States)

    Lv, Mengxian; Wang, Miao; Cai, Weiwei; Hao, Wenxing; Yuan, Panhong; Kang, Zhen

    2016-05-20

    Hyaluronan oligosaccharides (o-HAs), especially saturated o-HAs, have attracted intensive attention due to their potential applications in medical treatments. In this study, the hydrolysis process of leech hyaluronidase (LHase) towards the hyaluronan was investigated by HPLC and HPLC/ESI-MS. The proportions of hyaluronan tetrasaccharide (HA4) with hexasaccharide (HA6), end products, were illustrated to have a relationship with the amount of LHase. Higher yield of HA4 was achieved with higher activity of LHase. After optimisation of the packing resin and operation parameters (balanced pH, elution concentration, elution volume and elution flow rate), the highly pure HA4 and HA6 were efficiently separated and prepared by combining ion exchange Q-Sepharose Fast Flow and size exclusion column chromatography. Compared with o-HAs (average Mr of 4000 Da), HA4 and HA6 were demonstrated to show higher activity for promoting angiogenesis, which was similar with the corresponding HA4 and HA6 produced by bovine testicular hyaluronidase. The pure HA4 and HA6 that prepared from LHase will attract intensive studies and be used in potential applications in near future. PMID:26917404

  2. Efficacy of chitosan oligosaccharide as aquatic adjuvant administrated with a formalin-inactivated Vibrio anguillarum vaccine.

    Science.gov (United States)

    Liu, Xiaohong; Zhang, Hua; Gao, Yuan; Zhang, Yang; Wu, Haizhen; Zhang, Yuanxing

    2015-12-01

    Vaccine is one of the efficient candidates to prevent fish disease through activating host immune response in aquaculture. Actually, several vaccines are often administered with adjuvants to increase immunostimulation, especially for some water-based formalin-killed vaccines. However, side effects are inevitable after vaccination of some adjuvants. Therefore, exploration for effective and harmless aquatic adjuvants is urgently needed. In this study, immunoprotection of a formalin-inactivated Vibrio anguillarum vaccine applied with chitosan oligosaccharide (COS) was analyzed. High levels of protection were achieved in zebrafish and turbot vaccinated with inactivated vaccine and COS (RPS of 89.0 ± 4.5% and 80.0 ± 6.9%) compared with fish vaccinated with inactivated vaccine alone (RPS of 47.8 ± 6.6% and 64.7 ± 5.8%) at 4 week post vaccination. Moreover, high antibody reaction and cross-protection against Vibrio alginolyticus and Vibrio harveyi were observed of turbot vaccinated with inactivated vaccine and COS. In conclusion, COS can enhance immunoprotection of a formalin-inactivated V. anguillarum vaccine, significantly activate humoral immune response of host, and be benefit for inhibition against pathogens. Therefore, COS would be a potential adjuvant for aquatic vaccine design in the future. PMID:26476108

  3. Starch and chitosan oligosaccharides as interpenetrating phases in poly(N-isopropylacrylamide) injectable gels

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Jacquelin N.; Posada, James J. [Chemistry Department, B" 5IDA Research Group, Universidad Simón Bolívar, Caracas (Venezuela, Bolivarian Republic of); Rezende, Rodrigo A. [Divisão de Tecnologias Tridimensionais–Centro de Tecnologia da Informação Renato Archer, Campinas, SP (Brazil); Sabino, Marcos A., E-mail: msabino@usb.ve [Chemistry Department, B" 5IDA Research Group, Universidad Simón Bolívar, Caracas (Venezuela, Bolivarian Republic of); Divisão de Tecnologias Tridimensionais–Centro de Tecnologia da Informação Renato Archer, Campinas, SP (Brazil)

    2014-04-01

    Thermosensitive interpenetrating gels were prepared by physically blending poly(N-isopropylacrylamide) (PNIPA) as the matrix and the following polysaccharides as interpenetrating phases: chitosan oligosaccharides (identified as QNAD and QNED) and soluble starch (STARCH). The molecular weight of the dispersed phase, the free water/bound water ratio and the thermosensitivity (transition temperature: LCST) of the gels were determined. It was found that these gels are pseudoplastic and that their viscosity depends on the molecular weight of the dispersed phase. LCST transition occurred around 35–37 °C. The morphology of the porosity of the freeze-dried samples was studied by Scanning Electron Microscopy (SEM). An in vitro test of cell hemolysis on blood agar showed that these gels are noncytotoxic. According to the results obtained, these interpenetrating gels show characteristics of an injectable material, and have a transition LCST at body temperature, which reinforces their potential to be used in the surgical field and as scaffolds for tissue engineering. - Highlights: • Physical blends were prepared to obtain thermosensitive gels PNIPA/polysaccharides. • Rheological test allowed verifying the injectability of the gels. • Gels showed a LCST ∼ 37 °C, which makes them interesting for biomedical applications. • Porosity is a function of hydrophobicity/hydrophilicity/molecular weight of phases. • The PNIPA/starch gel showed better morphology as scaffold for tissue engineering.

  4. Effects of Xylo-Oligosaccharides on Broiler Chicken Performance and Microbiota.

    Science.gov (United States)

    De Maesschalck, C; Eeckhaut, V; Maertens, L; De Lange, L; Marchal, L; Nezer, C; De Baere, S; Croubels, S; Daube, G; Dewulf, J; Haesebrouck, F; Ducatelle, R; Taminau, B; Van Immerseel, F

    2015-09-01

    In broiler chickens, feed additives, including prebiotics, are widely used to improve gut health and to stimulate performance. Xylo-oligosaccharides (XOS) are hydrolytic degradation products of arabinoxylans that can be fermented by the gut microbiota. In the current study, we aimed to analyze the prebiotic properties of XOS when added to the broiler diet. Administration of XOS to chickens, in addition to a wheat-rye-based diet, significantly improved the feed conversion ratio. XOS significantly increased villus length in the ileum. It also significantly increased numbers of lactobacilli in the colon and Clostridium cluster XIVa in the ceca. Moreover, the number of gene copies encoding the key bacterial enzyme for butyrate production, butyryl-coenzyme A (butyryl-CoA):acetate CoA transferase, was significantly increased in the ceca of chickens administered XOS. In this group of chickens, at the species level, Lactobacillus crispatus and Anaerostipes butyraticus were significantly increased in abundance in the colon and cecum, respectively. In vitro fermentation of XOS revealed cross-feeding between L. crispatus and A. butyraticus. Lactate, produced by L. crispatus during XOS fermentation, was utilized by the butyrate-producing Anaerostipes species. These data show the beneficial effects of XOS on broiler performance when added to the feed, which potentially can be explained by stimulation of butyrate-producing bacteria through cross-feeding of lactate and subsequent effects of butyrate on gastrointestinal function. PMID:26092452

  5. Characterization of Pullulan/Chitosan Oligosaccharide/Montmorillonite Nanofibers Prepared by Electrospinning Technique.

    Science.gov (United States)

    Rabbani, Mohammad Mahbub; Yang, Seong Baek; Park, Soo-Jin; Oh, Weontae; Yeum, Jeong Hyun

    2016-06-01

    Pullulan/Chitosan oligosaccharide (COS)/Montmorillonite (MMT) hybrid nanofibers were electrospun from their aqueous solution using different Pullulan/COS mass ratios and variable amounts of MMT. The effects of Pullulan/COS mass ratios and MMT contents on the morphologies and properties of PulluIan/COS/MMT hybrid nanofibers were investigated. The obtained nanofibers were characterized with field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermo gravimetric analysis (TGA), and tensile strength measurement. The Pullulan/COS mass ratio and MMT contents significantly influence the morphologies and properties of the Pullulan/COS/MMT hybrid nanofibers. Higher Pullulan contents than COS contents forms uniform and bead free nanofibers. The addition of COS to Pullulan improves the thermal stability of Pullulan/COS blend nanofibers. The incorporation of MMT to the Pullulan/COS/MMT hybrid nanofibers increase their fiber diameter, improves their thermal stability and tensile strength. These morphological changes and property enhancement depend on the amount of MMT added. The XRD and TEM results suggest the coexistence of Pullulan, COS and MMT within polymer matrix through intercalation of polymer chain between silicate layers forming well-ordered multiplayer morphology with alternating polymeric and silicate layers. PMID:27427741

  6. Effect of mannan oligosaccharides and enzyme utilization on broiler bone parameters

    Directory of Open Access Journals (Sweden)

    Eliana Aparecida Rodrigues

    2009-12-01

    Full Text Available Mineral levels, weight, morphometry, breaking resistance and density of tibia from broilers fed on diets, supplemented or not with mannan oligosaccharides (MOS and/or enzymes, were evaluated. Seven hundred and fifty birds were used in a completely randomized design and factorial arrangement: 2 x 2 + 1 – two MOS levels (0 and 0.1%/0.05%, from 1 to 21/22 to 42 days x two enzyme levels (0 and 0.05% + positive control diet with antibiotics, totalling five treatments with five replicates. At 42 days of age, 50 birds were sacrificed for tibia analyses. There was no effect (P >0.05 of positive control x factorial or MOS x enzyme interactions on P and mineral matter levels, length and distal epiphysis density. MOS inclusion increased Ca levels (P <0.05. Enzymatic supplementation reduced (P <0.04 the weight, diameter and breaking resistance of tibia. Positive control x factorial interaction was significant (P <0.01 for diaphysis and average density, and birds fed diets with no additives had tibia with lower densities than those from the control treatment. It was concluded that diets with reduced crude protein and metabolizable energy of 2%, supplemented with MOS, can be used for broilers with no negative effects on the bone quality.

  7. Nondigestible oligosaccharides increase calcium absorption and suppress bone resorption in ovariectomized rats.

    Science.gov (United States)

    Zafar, Tasleem A; Weaver, Connie M; Zhao, Yongdong; Martin, Berdine R; Wastney, Meryl E

    2004-02-01

    Nondigestible oligosaccharides (NDO) including inulin and fructooligosaccharides (FOS) have been reported to stimulate calcium absorption. Here we report the effect of a mixture of inulin and FOS (Raftilose Synergy 1, Orafti) on calcium and bone metabolism in ovariectomized (OVX) rats. OVX rats (6 mo old) were fed a semipurified diet for 3 mo in our animal care laboratory for stabilization after ovariectomy. They were then divided into two groups (n = 13/group) and fed either a control or a NDO-supplemented diet (55 g/kg) for 21 d. Catheters were placed in their jugular veins. After 2 d, a tracer ((45)Ca) was administered by gavage or i.v. and blood was sampled for up to 300 min. Urine and fecal samples were collected for 4 d after (45)Ca administration. Femurs were measured for bone mineral density (BMD), breaking strength, and total calcium. Calcium absorption, femoral calcium content, BMD, and bone balance (V(bal)) were significantly increased (P calcium absorption and retention in ovariectomized rats.

  8. Feruloylated Oligosaccharides from Maize Bran Modulated the Gut Microbiota in Rats.

    Science.gov (United States)

    Ou, Juan-Ying; Huang, Jun-Qing; Song, Yuan; Yao, Sheng-Wen; Peng, Xi-Chun; Wang, Ming-Fu; Ou, Shi-Yi

    2016-06-01

    Corn bran is a byproduct produced from corn milling; it is rich in ferulic acid and hemicellulose. In this research, the effects of feruloylated oligosaccharides (FOs) from maize bran on the microbial diversity and profiles in rat feces were investigated through 16S rRNA sequencing. FOs significantly increased bacterial richness and diversity compared with the control and xylooligosaccharides (XOS) alone. In comparison with the control group and the group administrated with XOS, FOs orally administered at 300 mg/kg increased OTU in feces by 57.0 and 24.8 %, and Chao value by 93.4 and 37.6 %, respectively. FOs also influenced obesity- and diabetes-associated bacteria. Oral administration of FOs at 300 mg/kg decreased the ratio of Firmicutes to Bacteroidetes from 477.7:1 to 55.1:1; greatly increased the reads of bacteria that were previously found resistant against diabetes in rats, such as Actinobacteria, Bacteroides, and Lactobacillus; whereas decreased diabetes-prone bacteria, such as Clostridium and Firmicutes. PMID:27165128

  9. Chitosan oligosaccharide based Gd-DTPA complex as a potential bimodal magnetic resonance imaging contrast agent.

    Science.gov (United States)

    Huang, Yan; Cao, Juan; Zhang, Qi; Lu, Zheng-rong; Hua, Ming-qing; Zhang, Xiao-yan; Gao, Hu

    2016-01-01

    A new gadolinium diethylenetriamine pentaacetic acid (DTPA) complex (Gd-DTPA-DMABA-CS11) as a potential bimodal magnetic resonance imaging (MRI) contrast agent with fluorescence was synthesized. It was synthesized by the incorporation of 4-dimethylaminobenzaldehyde (DMABA) and chitosan oligosaccharide (CSn; n=11) with low polydispersity index to DTPA anhydride and then chelated with gadolinium chloride. The structure was characterized by Fourier transform infrared (FTIR), (1)H NMR, elemental analysis and size exclusion chromatography (SEC). MRI measurements in vitro were evaluated. The results indicated that Gd-DTPA-DMABA-CS11 provided higher molar longitudinal relaxivity (r1) (12.95mM(-1)·s(-1)) than that of commercial Gd-DTPA (3.63mM(-1)·s(-1)) at 0.5T. Gd-DTPA-DMABA-CS11 also emitted fluorescence, and the intensity was much stronger than that of Gd-DTPA. Therefore, it can be meanwhile used in fluorescent imaging for improving the sensitivity in clinic diagnosis. Gd-DTPA-DMABA-CS11 as a potential contrast agent is preliminarily stable in vitro. The results of thermodynamic action between Gd-DTPA-DMABA-CS11 and bovine serum albumin (BSA) illustrated that the binding process was exothermic and spontaneous, and the main force was van der Waals' interaction and hydrogen bond. The preliminary study suggested that Gd-DTPA-DMABA-CS11 could be used in both magnetic resonance and fluorescent imaging as a promising bimodal contrast agent.

  10. Low level of galacto-oligosaccharide in infant formula stimulates growth of intestinal Bifidobacteria and Lactobacilli

    Institute of Scientific and Technical Information of China (English)

    Xiao-Ming Ben; Juan Li; Zong-Tai Feng; Sheng-Yun Shi; Ya-Dong Lu; Rui Chen; Xiao-Yu Zhou

    2008-01-01

    AIM: To investigate the effect of a new infant formula supplemented with a low level (0.24 g/100 mL) of galacto-oligosaccharide (GOS) on intestinal micro-fiord (Bifidobacteria, Lactobacilli and E. coli) and fermentation characteristics in term infants, compared with human milk and a standard infant formula without GOS. METHODS: Term infants (n = 371) were approached in this study in three hospitals of China. All infants started breast-feeding. Those who changed to formula-feeding within 4 wk after birth were randomly assigned to one of the two formula groups. Growth and stool characteristics, and side effects that occurred in recruited infants were recorded in a 3-mo follow-up period. Fecal samples were collected from a subpopulation of recruited infants for analysis of intestinal bacteria (culture technique), acetic acid (gas chromatography) and pH (indicator strip). RESULTS: After 3 mo, the intestinal Bifidobacteria, Lactobac////, acetic acid and stool frequency were significantly increased, and fecal pH was decreased in infants fed with the GOS-formula or human milk, compared with those fed with the formula without GOS. No significant differences were observed between the GOS formula and human milk groups. Supplementation with GOS did not influence the incidence of crying, regurgitation and vomiting. CONCLUSION: A low level of GOS (0.24 g/100 mL) in infant formula can improve stool frequency, decrease fecal pH, and stimulate intestinal Bifidobacteria and Lactobacilli as in those fed with human milk.

  11. The human milk oligosaccharide 2'-fucosyllactose augments the adaptive response to extensive intestinal.

    Science.gov (United States)

    Mezoff, Ethan A; Hawkins, Jennifer A; Ollberding, Nicholas J; Karns, Rebekah; Morrow, Ardythe L; Helmrath, Michael A

    2016-03-15

    Intestinal resection resulting in short bowel syndrome (SBS) carries a heavy burden of long-term morbidity, mortality, and cost of care, which can be attenuated with strategies that improve intestinal adaptation. SBS infants fed human milk, compared with formula, have more rapid intestinal adaptation. We tested the hypothesis that the major noncaloric human milk oligosaccharide 2'-fucosyllactose (2'-FL) contributes to the adaptive response after intestinal resection. Using a previously described murine model of intestinal adaptation, we demonstrated increased weight gain from 21 to 56 days (P < 0.001) and crypt depth at 56 days (P < 0.0095) with 2'-FL supplementation after ileocecal resection. Furthermore, 2'-FL increased small bowel luminal content microbial alpha diversity following resection (P < 0.005) and stimulated a bloom in organisms of the genus Parabacteroides (log2-fold = 4.1, P = 0.035). Finally, transcriptional analysis of the intestine revealed enriched ontologies and pathways related to antimicrobial peptides, metabolism, and energy processing. We conclude that 2'-FL supplementation following ileocecal resection increases weight gain, energy availability through microbial community modulation, and histological changes consistent with improved adaptation.

  12. Promotive effects of alginate-derived oligosaccharides on the inducing drought resistance of tomato

    Science.gov (United States)

    Liu, Ruizhi; Jiang, Xiaolu; Guan, Huashi; Li, Xiaoxia; Du, Yishuai; Wang, Peng; Mou, Haijin

    2009-09-01

    In order to determine the role of alginate-derived oligosaccharides (ADO) in drought stress resistance of tomato ( Lycopersicon esculentum Miller) seedlings, the leaves were exposed to different concentrations of ADO (0.05%, 0.10%, 0.20%, 0.30% and 0.50%) after drought stress was simulated by exposing the roots to 0.6 molL-1 PEG-6000 solution for 6 h. Changes in biomass, electrolyte leakage and malondialdehyde (MDA), free proline, total soluble sugars (TSS) and abscisic acid (ABA), the enzyme activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD) and phenylalanine ammonia-lyase (PAL) were measured to investigate the effects of ADO treatment. The results showed that the treatment with an ADO concentration of 0.20% exhibited the highest performance of drought stress resistance in the tomato seedlings by decreasing the electrolyte leakage and the concentration of MDA, increasing the contents of free proline, TSS and ABA, and increasing the activities of CAT, SOD, POD and PAL after treatment with ADO. It is suggested that changes in electrolyte leakage, MDA, osmotic solutes, ABA, anti-oxidative enzyme and PAL activities were responsible for the increased drought stress resistance in tomato seedlings. To our best knowledge, this is the first report of the effect of ADO treatment on enhancing the drought stress resistance of tomato seedlings.

  13. Promotive Effects of Alginate-Derived Oligosaccharides on the Inducing Drought Resistance of Tomato

    Institute of Scientific and Technical Information of China (English)

    LIU Ruizhi; JIANG Xiaolu; GUAN Huashi; LI Xiaoxia; DU Yishuai; WANG Peng; MOU Haijin

    2009-01-01

    In order to determine the role of alginate-derived oligosaccharides (ADO) in drought stress resistance of tomato (Lycopersicon esculentum Miller) seedlings, the leaves were exposed to different concentrations of ADO (0.05%, 0.10%, 0.20%, 0.30% and 0.50%) after drought stress was simulated by exposing the roots to 0.6molL-I PEG-6000 solution for 6h. Changes in biomass, electrolyte leakage and malondialdehyde (MDA), free proline, total soluble sugars (TSS) and abscisic acid (ABA), the enzyme activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD) and phenylalanine ammonia-lyase (PAL) were measured to investigate the effects of ADO treatment. The results showed that the treatment with an ADO concentration of 0.20% exhibited the highest performance of drought stress resistance in the tomato seedlings by decreasing the electrolyte leakage and the concentration of MDA, increasing the contents of free proline, TSS and ABA, and increasing the activities of CAT, SOD, POD and PAL after treatment with ADO. It is suggested that changes in electrolyte leakage, MDA, osmotic solutes, ABA, anti-oxidative enzyme and PAL activities were responsible for the increased drought stress resistance in tomato seedlings. To our best knowledge, this is the first report of the effect of ADO treatment on enhancing the drought stress resistance of tomato seedlings.

  14. Effects of Mannan Oligosaccharide and Saccharomyces cerevisiae on Gut Morphology of Broiler Chickens

    Directory of Open Access Journals (Sweden)

    Veena Pani Padihari

    2014-09-01

    Full Text Available 150 day old Vencobb broiler chicks were randomly allocated to 5 treatment groups with 3 replicates of 10 chicks in each to determine the effect of mannan oligosaccharide (MOS and Saccharomyces cerevisiae in gut morphology of broilers. The trial lasted for 6 weeks. For microscopic examination the representative samples of each segment of intestine were collected and fixed in the 10% buffered formalin. No significant difference was observed in treatments at length of different segments of intestine and villus height/crypt depth ratio. Significant (P< 0.05 difference observed for the mean height of the duodenum, jejunum, and ileum villus amongst different dietary treatments, being highest in T5 and lowest in T2. Mean crypt depth of the duodenum and ileum villus also differed significantly (P< 0.05 amongst treatments. The highest mean crypt depth in the duodenum was recorded in T5 and lowest in T2 whereas the highest mean crypt depth of caecum was recorded in T3 and the lowest in T1. Thickness of tunica muscularis was significantly (P< 0.05 decreased in all segments of intestine except colorectum as MOS and S. cerevisae added to the diet. Height of the epithelium of villi differed significantly (P< 0.05 amongst treatments in all segments of intestine except caecum being maximum in T5 and minimum in T2. It was concluded that supplementation of MOS and S. cerevisiae improves the gut health of broiler chickens.

  15. Rice Bran Feruloylated Oligosaccharides Activate Dendritic Cells via Toll-Like Receptor 2 and 4 Signaling

    Directory of Open Access Journals (Sweden)

    Chi Chen Lin

    2014-04-01

    Full Text Available This work presents the effects of feruloylated oligosaccharides (FOs of rice bran on murine bone marrow-derived dendritic cells (BMDCs and the potential pathway through which the effects are mediated. We found that FOs induced phenotypic maturation of DCs, as shown by the increased expression of CD40, CD80/CD86 and MHC-I/II molecules. FOs efficiently induced maturation of DCs generated from C3H/HeN or C57BL/6 mice with normal toll-like receptor 4 (TLR-4 or TLR-2 but not DCs from mice with mutated TLR4 or TLR2. The mechanism of action of FOs may be mediated by increased phosphorylation of ERK, p38 and JNK mitogen-activated protein kinase (MAPKs and increased NF-kB activity, which are important signaling molecules downstream of TLR-4 and TLR-2. These data suggest that FOs induce DCs maturation through TLR-4 and/or TLR-2 and that FOs might have potential efficacy against tumor or virus infection or represent a candidate-adjuvant approach for application in immunotherapy and vaccination.

  16. Human milk oligosaccharides protect bladder epithelial cells against uropathogenic Escherichia coli invasion and cytotoxicity.

    Science.gov (United States)

    Lin, Ann E; Autran, Chloe A; Espanola, Sophia D; Bode, Lars; Nizet, Victor

    2014-02-01

    The invasive pathogen uropathogenic Escherichia coli (UPEC) is the primary cause of urinary tract infections (UTIs). Recurrent infection that can progress to life-threatening renal failure has remained as a serious global health concern in infants. UPEC adheres to and invades bladder epithelial cells to establish infection. Studies have detected the presence of human milk oligosaccharides (HMOs) in urine of breast-fed, but not formula-fed, neonates. We investigated the mechanisms HMOs deploy to elicit protection in human bladder epithelial cells infected with UPEC CFT073, a prototypic urosepsis-associated strain. We found a significant reduction in UPEC internalization into HMO-pretreated epithelial cells without observing any significant effect in UPEC binding to these cells. This event coincides with a rapid decrease in host cell cytotoxicity, recognized by LIVE/DEAD staining and cell detachment, but independent of caspase-mediated or mitochondrial-mediated programmed cell death pathways. Further investigation revealed HMOs, and particularly the sialic acid-containing fraction, reduced UPEC-mediated MAPK and NF-κB activation. Collectively, our results indicate that HMOs can protect bladder epithelial cells from deleterious cytotoxic and proinflammatory effects of UPEC infection, and may be one contributing mechanism underlying the epidemiological evidence of reduced UTI incidence in breast-fed infants.

  17. Rice bran feruloylated oligosaccharides activate dendritic cells via Toll-like receptor 2 and 4 signaling.

    Science.gov (United States)

    Lin, Chi Chen; Chen, Hua Han; Chen, Yu Kuo; Chang, Hung Chia; Lin, Ping Yi; Pan, I-Hong; Chen, Der-Yuan; Chen, Chuan Mu; Lin, Su Yi

    2014-01-01

    This work presents the effects of feruloylated oligosaccharides (FOs) of rice bran on murine bone marrow-derived dendritic cells (BMDCs) and the potential pathway through which the effects are mediated. We found that FOs induced phenotypic maturation of DCs, as shown by the increased expression of CD40, CD80/CD86 and MHC-I/II molecules. FOs efficiently induced maturation of DCs generated from C3H/HeN or C57BL/6 mice with normal toll-like receptor 4 (TLR-4) or TLR-2 but not DCs from mice with mutated TLR4 or TLR2. The mechanism of action of FOs may be mediated by increased phosphorylation of ERK, p38 and JNK mitogen-activated protein kinase (MAPKs) and increased NF-kB activity, which are important signaling molecules downstream of TLR-4 and TLR-2. These data suggest that FOs induce DCs maturation through TLR-4 and/or TLR-2 and that FOs might have potential efficacy against tumor or virus infection or represent a candidate-adjuvant approach for application in immunotherapy and vaccination. PMID:24762969

  18. In vitro effect of dietary protein level and nondigestible oligosaccharides on feline fecal microbiota.

    Science.gov (United States)

    Pinna, C; Stefanelli, C; Biagi, G

    2014-12-01

    The aim of the present study was to evaluate in vitro the effect of some prebiotic substances and 2 dietary protein levels on the composition and activity of feline fecal microbiota. Two in vitro studies were conducted. First, 6 nondigestible oligosaccharides were studied; treatments were control diet (CTRL), gluconic acid (GA), carrot fiber (CF), fructooligosaccharides (FOS), galactooligosaccharides (GOS), lactitol (LAC), and pectins from citrus fruit (PEC). Substrates were added to feline fecal cultures at 2 g/L for 24 h incubation. Compared with the CTRL, ammonia had been reduced (PFOS (+90%), GOS (+96%), and LAC (+87%). Compared with the CTRL, total VFA were higher (PFOS were selected to be tested in the presence of 2 diets differing in their protein content. There were 6 treatments: low-protein (LP) CTRL with no addition of prebiotics (CTRL-LP), high-protein (HP) CTRL with no addition of prebiotics (CTRL-HP), LP diet plus FOS, CTRL-HP plus FOS, LP diet plus LAC, and CTRL-HP plus LAC. Both FOS and LAC were added to feline fecal cultures at 2 g/L for 24 h incubation. Ammonia at 24 h was affected (PFOS. Total VFA were influenced (Pprebiotics exert different effects on the composition and activity of feline intestinal microbiota and that high dietary protein levels in a cat's diet can have negative effects on the animal intestinal environment. PMID:25367521

  19. Inhibition of fungal plant pathogens by synergistic action of chito-oligosaccharides and commercially available fungicides.

    Directory of Open Access Journals (Sweden)

    Md Hafizur Rahman

    Full Text Available Chitosan is a linear heteropolymer consisting of β 1,4-linked N-acetyl-D-glucosamine (GlcNAc and D-glucosamine (GlcN. We have compared the antifungal activity of chitosan with DPn (average degree of polymerization 206 and FA (fraction of acetylation 0.15 and of enzymatically produced chito-oligosaccharides (CHOS of different DPn alone and in combination with commercially available synthetic fungicides, against Botrytis cinerea, the causative agent of gray mold in numerous fruit and vegetable crops. CHOS with DPn in the range of 15-40 had the greatest anti-fungal activity. The combination of CHOS and low dosages of synthetic fungicides showed synergistic effects on antifungal activity in both in vitro and in vivo assays. Our study shows that CHOS enhance the activity of commercially available fungicides. Thus, addition of CHOS, available as a nontoxic byproduct of the shellfish industry, may reduce the amounts of fungicides that are needed to control plant diseases.

  20. Assessment of suitability of vine shoots for hemicellulosic oligosaccharides production through aqueous processing.

    Science.gov (United States)

    Dávila, Izaskun; Gordobil, Oihana; Labidi, Jalel; Gullón, Patricia

    2016-07-01

    Vine shoots were subjected to non-isothermal aqueous processing. A range of severities (S0) from 3.20 to 4.65 was assayed and their effects in terms of solubilization, composition, molar mass distribution, structural characterization and thermal stability of the liquors were studied using HPLC, HPSEC, TGA and FTIR. The spent solids were characterized by HPLC and FTIR. When autohydrolysis was carried out at S0=4.01, the substrate solubilization achieved a 38.7% of the raw material and 83.1% of the initial xylan was converted into xylooligosaccharides (XOS). The amount of TOS (total oligosaccharides) in the hydrolysates was 28.4g/L while the other non volatile compounds (ONVC) were 0.08g/g NVC. The spent solid from the treatment at S0=4.01 was composed about 90% of cellulose and lignin. Therefore, it can be concluded that autohydrolysis is a suitable pretreatment of vine shoots such as a first stage of a biomass refinery. PMID:27054881