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Carbohydrate Research

Qaojuan Yan, Hongye Yang, Zhengqiang Jiang, Erwei Liu, Shaoqing Yang
Fermentation conditions for β-1,3-1,4-glucanase (TaGlu34) production in submerged culture by a thermophilic fungus, Thermoascus aurantiacus CAU830 were optimized. The highest enzyme activity of 3741 U/mL was obtained, and the crude enzyme was purified to homogeneity with a purification fold of 7.3 and a recovery yield of 11.6%. The molecular mass of the purified enzyme was estimated to be approximately 34 kDa on SDS-PAGE. TaGlu34 was most active at pH 6.0 and 75 °C, respectively. It showed excellent thermostability with thermal denaturing half-lives of 209, 130 and 69 min at 50, 60 and 70 °C, respectively...
September 5, 2018: Carbohydrate Research
Laxminarayan Sahoo, Soumya Kundu, Anadi Singhamahapatra, Naresh K Jena, Ganesh C Nayak, Satyanarayan Sahoo
In recent years, 1,4-triazole rings are being widely used for the synthesis of carbohydrate derived biomimetics, due to their easy synthesis and wide range of functional group compatibility. These triazole rings lead to synthetic molecules with improved enzymatic stability, bioavailability, and structural diversity. In this present work, a benzoyl group has been introduced at the C-5 position of the triazole ring present in the synthetic glycoconjugates providing further structural diversity to the molecule...
August 31, 2018: Carbohydrate Research
Mojtaba Tabandeh, Ean Wai Goh, Abbas Abdulameer Salman, Thorsten Heidelberg, Rusnah Syahila Duali Hussen
Two azide-terminated oligoethylene oxide spacered glycolipids have been synthesized, and their assembly behavior has been studied in comparison to the corresponding base surfactants. The results suggest potential of the Guerbet lactoside-based compound for targeted drug delivery, while a coiling of the ethylene oxide linker disfavors the application of the glucoside.
August 30, 2018: Carbohydrate Research
Ying Xiao, Zimin Lu, Xiang Zhao, Pingru Wu, Wei Chen, Ruobing Wang, Jing Zeng, Qian Wan
A catalytic and metal free sulfoxidation of O-2-(2-propylthiol)benzyl (OPTB) glycosides to O-2-(2-propylsulfinyl)benzyl (OPSB) glycosides has been developed by introducing NOBF4 as catalyst, oxygen as terminal oxidant and TBAB as additive. Wide variety of OPTB glycosides were efficiently oxidized without observation of over oxidation. The allowance of large scale synthesis, easy operation and purification highlighted its practical application in construction of complex oligosaccharides and glycoconjugates employing interrupted Pummerer reaction mediated glycosylation strategy...
August 24, 2018: Carbohydrate Research
Hye-Bin Kim, Kyung-Tai Lee, Min-Ju Kim, Jin-Sung Lee, Keun-Sung Kim
This study was conducted to isolate and functionally characterize a novel xylan-degrading enzyme from the microbial metagenomes of black goat rumens. A novel gene, KG42, was isolated from one of the 17 xylan-degrading metagenomic fosmid clones obtained from black goat rumens. The KG42 gene, comprising a 1107 bp open reading frame, encodes a protein composed of 368 amino acids (41 kDa) with a glycosyl hydrolase family 10 (GH10) domain, consisting of a "salad-bowl" shaped tertiary structure (a typical 8-fold α/β barrel (α/β)8) and two catalytic residues...
August 22, 2018: Carbohydrate Research
Hong-Ming Chen, Stephen G Withers
Azide- and amine-substituted sugars can be useful tools in the probing of biological systems as well as in the assembly of libraries of derivatives using click chemistry or simple amine coupling approaches. A collection of methylumbelliferyl glycosides of various azido- and amino-deoxy sugar derivatives of glucose, galactose and xylose was synthesised via azide displacement of the corresponding triflate derivatives and subsequent modification. These compounds will be used as substrates in a high-throughput screen to identify glycosidases that can process such modified sugars...
July 27, 2018: Carbohydrate Research
Alexandra S Silchenko, Anatoly I Kalinovsky, Sergey A Avilov, Pelageya V Andryjaschenko, Pavel S Dmitrenok, Ekaterina A Yurchenko, Svetlana P Ermakova, Olesya S Malyarenko, Igor Yu Dolmatov, Vladimir I Kalinin
The sea cucumber Cladolabes schmeltzii (Sclerodactylidae, Dendrochirotida) contains diverse glycosides, including several dozen individual compounds. Six new triterpene oligoglycosides, cladolosides O (1), P (2), P1 (3), P2 (4), P3 (5) and R (6), were isolated from this sea cucumber. Their structures were elucidated by 2D NMR spectroscopy and HR ESI mass spectrometry. Cladoloside O (1) has a pentasaccharide carbohydrate chain. Cladolosides of the group P and cladoloside R (6) include novel hexasaccharide carbohydrate chains with different positions of non-methylated terminal sugar units...
October 2018: Carbohydrate Research
Evgeny Vinogradov, Frank St Michael, Andrew D Cox
Fusobacterium nucleatum is an anaerobic bacterium found in the human mouth where it causes periodontitis. It was also found in colorectal cancer tissues and is linked with pregnancy complications, including pre-term and still births. Cell surface structures of the bacterium could be implicated in pathogenesis. Here we report the following structure of the lipopolysaccharide O-chain of a spontaneous streptomycin resistant (SmR) mutant of F. nucleatum strain ATCC 23726: -4-β-Non5Am7Ac-4-β-d-GlcNAcyl3NFoAN-3-β-d-FucNAc4N- where GlcNAcyl3NFoAN indicates 2,3-diamino-2,3-dideoxyglucuronic acid amide with Fo at N-3 being formyl and Acyl at N-2 being propanoyl (∼70%) or butanoyl (∼30%); Non5Am7Ac indicates 7-acetamido-5-acetimidoylamino-3,5,7,9-tetradeoxy-l-gluco-non-2-ulosonic acid presumably having the d-glycero-l-gluco configuration...
October 2018: Carbohydrate Research
Sateesh Dubbu, Ande Chennaiah, Ashish Kumar Verma, Yashwant D Vankar
2-Deoxy-β-C-aryl/alkyl glycosides were synthesized from di-O-pivaloyl protected homoallylic alcohol derived from D-mannitol with various aldehydes via the Prins cyclization. The salient features of this methodology are high yields and excellent stereoselectivity. This method has also been successfully applied to the synthesis of differently protected 2-deoxy-β-C-aryl glycosides and C-disaccharides. One of the 2-deoxy-β-C-aryl glycosides was utilized as a glycosyl acceptor in the glycosylation to synthesize an O-linked disaccharides...
October 2018: Carbohydrate Research
Milica Fabišíková, Miroslava Martinková, Jozef Gonda, Dominika Jacková, Martina Bago Pilátová, Juraj Kuchár
Two approaches to a small library of cytotoxic dihydrosphingosine analogues are described. [3,3]-Sigmatropic rearrangements along with an OCM reaction were used as the key steps for the construction of the two isodihydrosphingosines ent-6 and 10, whereas the functional group manipulations, including Grubbs' metathesis chemistry, were applied to known isothiocyanate scaffolds 15 and 16 to provide access to the enantiomeric forms of ent-6 and 10 and diastereomeric isophytosphingosines ent-7.HCl and 14. Cell viability experiments revealed that the target isomeric sphingoid bases were more potent than the traditional anticancer agent cisplatin, with IC50 values in the low micromolar range for the most active compounds...
October 2018: Carbohydrate Research
Karina Espinoza, Jaime Eyzaguirre
Penicillium purpurogenum grows on a variety of natural carbon sources and secretes to the medium a large number of enzymes that degrade the polysaccharides present in lignocellulose. In this work, the gene coding for a novel xylanase (XynC) belonging to family 30 of the glycoside hydrolases (GH), has been identified in the genome of the fungus. The enzyme has been expressed in Pichia pastoris and characterized. The mature XynC has 454 amino acid residues and a calculated molecular weight of 49 240. The purified protein shows a molecular weight of 67 000, and it is partially deglycosylated using EndoH...
October 2018: Carbohydrate Research
Alexandra S Silchenko, Anatoly I Kalinovsky, Sergey A Avilov, Pelageya V Andryjaschenko, Pavel S Dmitrenok, Ekaterina A Yurchenko, Svetlana P Ermakova, Olesya S Malyarenko, Igor Yu Dolmatov, Vladimir I Kalinin
Eight new triterpene olygoglycosides, cladolosides C4 (1), D1 (2), D2 (3), M (4), M1 (5), M2 (6), N (7) and Q (8), were isolated from the tropical Indo-West Pacific sea cucumber Cladolabes schmeltzii (Sclerodactylidae, Dendrochirotida). Structures of these glycosides were elucidated by 2D NMR spectroscopy and HR ESI mass spectrometry. A novel hexasaccharide carbohydrate chain having xylose residues as the first, second and third sugars was found in the glycoside 7. Cladoloside C4 (1) contains an uncommon 20,21,22,23,24,25,26,27-octa-norlanostane aglycone...
October 2018: Carbohydrate Research
Krista A Barzen-Hanson, Rebecca A Wilkes, Ludmilla Aristilde
As remnants of plant wastes or plant secretions, carbohydrates are widely found in various environmental matrices. Carbohydrate-containing feedstocks represent important carbon sources for engineered bioproduction of commodity compounds. Routine monitoring and quantitation of heterogenous carbohydrate mixtures requires fast, accurate, and precise analytical methods. Here we present two methods to quantify carbohydrates mixtures by coupling hydrophilic interaction liquid chromatography with electrospray ionization high-resolution mass spectrometry...
October 2018: Carbohydrate Research
Keevan C Marion, Zachary Wooke, Nicola L B Pohl
Common carbohydrate protecting group reactions under continuous flow processes are reported in the context of producing partially-protected glucose building blocks from levoglucosan. Benzyl ether protection was demonstrated without the use of NaH using barium oxide, which, however, pointed to the need for forms of this catalyst not as susceptible to close packing under flow. Acylation conditions were developed under continuous flow in acetonitrile and avoiding pyridine. Ring-opening the derivatized levoglucosan with propanethiol was also demonstrated producing S-alkyl 2,4-di-O-benzyl-glucopyranoside building block in 2 rather than 12 steps in increased overall yield...
October 2018: Carbohydrate Research
Nobukiyo Tanaka, Masahiro Nakajima, Hiroki Aramasa, Hiroyuki Nakai, Hayao Taguchi, Wakako Tsuzuki, Shiro Komba
Sophorose (Sop2 ) is known as a powerful inducer of cellulases in Trichoderma reesei, and in recent years 1,2-β-D-oligoglucan phosphorylase (SOGP) has been found to use Sop2 in synthetic reactions. From the structure of the complex of SOGP with Sop2 , it was predicted that both the 3-hydroxy group at the reducing end glucose moiety of Sop2 and the 3'-hydroxy group at the non-reducing end glucose moiety of Sop2 were important for substrate recognition. In this study, three kinds of 3- and/or 3'-deoxy-Sop2 derivatives were synthesized to evaluate this mechanism...
October 2018: Carbohydrate Research
Jana Špaková Raschmanová, Miroslava Martinková, Jozef Gonda, Martina Bago Pilátová, Daniel Kupka, Dávid Jáger
A straightforward synthesis of l-lyxo- and l-xylo-phytosphingosine along with their isomeric analogues has been accomplished. The salient features of this approach are the utilization of [3,3]-sigmatropic rearrangements to install a C-N bond and application of a late stage Wittig or OCM reaction to incorporate the hydrophobic chain unit. The final compounds were evaluated regarding their ability to alter both leukaemia and solid tumor cancer cells viability.
October 2018: Carbohydrate Research
Huiying Liu, Xiao Zhang, Mingyi Wu, Zhongjun Li
Fucosylated chondroitin sulfate (FuCS) is a structurally complex glycosaminoglycan found in sea cucumbers with a wide spectrum of biological activities, among which anticoagulant activity is particularly attractive for the development of alternative anticoagulant drugs with decreased adverse effects and risks of bleeding. Previous studies show that FuCS glycomimetics bearing several trisaccharide epitopes displayed promising anticoagulant activity and did not change the mode of action of FuCS. To simplify synthetic difficulty of high valent glycoclusters and obtain candidate compounds with relatively low molecular weights, here we report the synthesis of two FuCS glycoclusters with low valence and more compact structures...
September 2018: Carbohydrate Research
Bo Meng, Jun Wang, Quanli Wang, Anthony S Serianni, Qingfeng Pan
Molecular recognition of mannose-6-phosphate (M6P)-modified oligosaccharides by transmembrane M6P receptors is a key signaling event in lysosomal protein trafficking in vivo. Access to M6P-containing high-mannose N-glycans is essential to achieving a thorough understanding of the M6P ligand-receptor recognition process. Herein we report the application of a versatile and reliable chemical strategy to prepare asymmetric di-antennary M6P-tagged high-mannose oligosaccharides in >20% overall yield and in high purity (>98%)...
September 2018: Carbohydrate Research
Bence Kutus, Gábor Peintler, Ákos Buckó, Zsolt Balla, Alexandru Lupan, Amr A A Attia, István Pálinkó, Pál Sipos
Lactonization and proton dissociation of sugar acids take place simultaneously in acidic aqueous solutions. The protonation-deprotonation processes are always fast, whilst the formation and hydrolysis of γ- and δ-lactones are usually slower. Thus, both thermodynamic and kinetic information are required for the complete understanding of these reactions. The protonation constant (Kp ) of l-gulonate (Gul- ) was determined from potentiometric and polarimetric measurements, while the individual lactonization constants (KL,γ and KL,δ ) for l-gulonic acid (HGul) were obtained via13 C NMR experiments...
September 2018: Carbohydrate Research
Kazuki Sato, Katsuya Hara, Yoshihisa Yoshimi, Kiminari Kitazawa, Haruka Ito, Yoichi Tsumuraya, Toshihisa Kotake
Larch arabinogalactan (AG) is classified as a plant type II AG. Its basic structure is constituted by a β-1,3-galactan main chain with β-1,6-galactan side chains. But its properties are distinct from other type II AGs. Whereas most type II AGs are found as glycan moieties of arabinogalactan-protein (AGP), larch AG lacks a protein moiety. Larch AG itself is also unlike other type II AGs as it lacks Yariv reactivity, the capability of AG to form insoluble precipitate with β-Yariv reagents, 1,3,5-tri-(p-glycosyloxyphenylazo)-2,4,6-trihydroxybenzene with β-glucosyl or β-galactosyl residues at the termini...
September 2018: Carbohydrate Research
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