- Water-soluble Glucosamine-coated AIE-Active Fluorescent Organic Nanoparticles: Design, Synthesis and Assembly for Specific Detection of Heparin Based on Carbohydrate–Carbohydrate Interactions
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Two water-soluble carbohydrate-coated AIE-activate fluorescent organic nanoparticles TPE3G and TPE4G were designed and synthesized for the detection of heparin. Different from the reported strategy, we not only utilized the general detection mechanism of
- Ji, Yan-ming,Liu, Guang-jian,Li, Cui-yun,Liu, Yi-chen,Hou, Min,Xing, Guo-wen
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- Synthesis of heteroaromatic N-β-glycosides of N-acetylglucosamine under the conditions of phase transfer catalysis: I. Glucosaminides of 2-oxobenzazoles
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Glycosylation of benzothiazolone-2, 5-methylbenzoxazolone-2, and benzothiazolone-2 with the full acetate of α-D-glucosaminyl chloride in the phase transfer systems investigated (solid-organic solvent and aqueous alkali-organic solvent) regioselectively leads to the corresponding N-β-D-glucosaminides, which is proved by 1H NMR spectroscopy and X-ray analysis.
- Kur'yanov,Chupakhina,Zemlyakov,Chirva,Shishkin,Shishkina,Kotlyar,Kamalov
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- A facile and quantitative preparation of activated cyclic sugar derivatives using HgBr2 and 2,4,6-collidine
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A combination of mercury(II) bromide (HgBr2) and 2,4,6-collidine was found to promote the formation of activated cyclic sugar derivatives such as 1,2-orthoesters and an oxazoline derivative in quantitative yields at room temperature. A slightly hindered skew like conformation of the lactose orthoester derivative was revealed by 1H NMR analysis. It was also suggested that the reaction of a lactose 1,2-orthoester with trimethylsilyl azide proceeded smoothly to give β-lactosyl azide stereoselectively which is a useful intermediate for constructing glycopeptides and neoglycoconjugates.
- Matsuoka,Nishimura,Lee
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- Sialidase inhibitors related to zanamivir: Synthesis and biological evaluation of 4H-pyran 6-ether and ketone
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Synthesis of 5R-Acetamido-4S-amino-4H-pyran-6R-O-(1-ethyl)propyl and 6R- (1-oxo-2-ethyl)butyl 2-carboxylic acids (4 and 5) and their evaluation as inhibitors of influenza virus sialidase is described. Both compounds showed good inhibitory activity with ma
- Smith, Paul W.,Robinson, J.Ed,Evans, Derek N.,Sollis, Steven L.,Howes, Peter D.,Trivedi, Naimisha,Bethell, Richard C.
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- Effect of fluorous tags on glycosylation of saccharide primers in animal cells
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A series of fluorous-tagged saccharide primers with different contents of fluorous atoms was synthesized and introduced into mouse melanoma B16 cells. The primers did not affect cell morphology and viability at a concentration of 50 μM. The numerous fluorine atoms did not pose a steric barrier to primer assimilation into cells and did not affect cellular-enzyme-catalyzed glycosylation. The lactoside primers were sialylated to afford GM3-type oligosaccharide. On the other hand, the GlcNAc primers were galactosylated to afford a lactosamine derivative that was further sialylated by cellular enzymes to afford a sialylated lactosamine.
- Kasuya, Maria Carmelita Z.,Tojino, Mami,Nakano, Shinya,Mizuno, Mamoru,Hatanaka, Kenichi
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- A new approach to the synthesis of ligands of asialoglycoprotein receptor for targeted delivery of oligonucleotides to hepatocytes
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A new approach to the synthesis of organic ligands of asialoglycoprotein receptor was suggested. It was shown that the azido-containing tervalent N-acetylglucosamine and N-acetylmannosamine derivatives obtained by this method can serve as convenient starting compounds for the synthesis of therapeutical conjugates with oligonucleotides containing a terminal alkyne.
- Maklakova, S. Yu,Kucherov,Petrov,Gopko,Shipulin,Zatsepin,Beloglazkina,Zyk,Majouga,Koteliansky
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- Site-selective depurination by a periodate-dependent deoxyribozyme
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A deoxyribozyme is identified that mediates the site-selective depurination of its 5′-terminal guanosine nucleotide using periodate (IO 4-) as an obligatory cofactor. The Royal Society of Chemistry.
- Hoebartner, Claudia,Pradeepkumar,Silverman, Scott K.
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- Design, Synthesis, and Preliminary Biological Evaluation of GlcNAc-6P Analogues for the Modulation of Phosphoacetylglucosamine Mutase 1 (AGM1/PGM3)
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A library of GlcNAc 6- or 1-phosphate analogues was designed, and each compound was evaluated computationally through docking studies for its binding affinity to AGM1/PGM3. The compounds with the highest binding affinity, as ranked through a docking score, were synthesised and screened for their ability to inhibit the production of UDP-GlcNAc. A glycofused oxazoline analogue showed good inhibition, and gave significant results in vitro.
- Paiotta, Alice,D'Orazio, Giuseppe,Palorini, Roberta,Ricciardiello, Francesca,Zoia, Luca,Votta, Giuseppina,De Gioia, Luca,Chiaradonna, Ferdinando,La Ferla, Barbara
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- Simple and Efficient Preparation of O- and S-GlcNAcylated Amino Acids through InBr3-Catalyzed Synthesis of β- N-Acetylglycosides from Commercially Available Reagents
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The facile synthesis of serine, threonine, and cysteine β-glycosides using commercially available peracetylated β-N-acetylglucosamine (β-Ac4GlcNAc) and catalytic amounts of indium bromide (InBr3) is described. This method involves only inexpensive reagents that require no further modification or special handling. The reagents are simply mixed, dissolved, and refluxed to afford the GlcNAcylated amino acids in great yields (70-80%). This operationally simple procedure should facilitate the study of O-GlcNAcylation without necessitating expertise in synthetic carbohydrate chemistry.
- De Leon, Cesar A.,Lang, Geoffrey,Saavedra, Marcos I.,Pratt, Matthew R.
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- Glycosylation of 5-phenyl-1,3,4-oxadiazole-2-thiol with α-D-glucopyranosyl chloride under phase transfer conditions
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5-Phenyl-1,3,4-oxadiazole-2-thiol is glycosylated easily and in high yields with 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-α-D-glucopyranosyl chloride in the presence of catalytic amounts of aliphatic and aromatic crown ethers under phase transfer (solid-organic solvent) conditions. The reaction rate and the ratio of the resulting N-and S-regioisomers depend on the catalyst nature. Pleiades Publishing, Inc., 2006.
- Kur'yanov,Kotlar,Priskoka,Chupakhina,Chirva
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- A novel method for synthesis of chitobiose via enzymatic glycosylation using a sugar oxazoline as glycosyl donor
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A convenient method for synthesis of N,N'-diacetylchitobiose, an important building block for oligo and polysaccharide synthesis, has been developed by using a 1,2-oxazoline derivative of N-acetylglucosamine as new glycosyl donor for chitinase.
- Kobayashi, Shiro,Kiyosada, Toshitsugu,Shoda, Shin-Ichiro
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- Photo-click immobilization on quartz crystal microbalance sensors for selective carbohydrate-protein interaction analyses
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A photoclick method based on azide photoligation and Cu-catalyzed azide-alkyne cycloaddition has been evaluated for the immobilization of carbohydrates to polymeric materials. The biomolecular recognition properties of the materials have been investigated with regard to applicable polymeric substrates and selectivity of protein binding. The method was used to functionalize a range of polymeric surfaces (polystyrene, polyacrylamide, polyethylene glycol), poly(2-ethyl-2-oxazoline), and polypropene) with various carbohydrate structures (based on α-D-mannose, β-D-galactose, and N-acetyl-β-D-glucosamine). The functionalized surfaces were evaluated in real-time studies of protein-carbohydrate interactions using a quartz crystal microbalance flow-through system with a series of different carbohydrate-binding proteins (lectins). The method proved to be robust and versatile, resulting in a range of efficient sensors showing high and predictable protein selectivities.
- Norberg, Oscar,Deng, Lingquan,Aastrup, Teodor,Yan, Mingdi,Ramstroem, Olof
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- Design, synthesis and biological evaluation of carbohydrate-functionalized cyclodextrins and liposomes for hepatocyte-specific targeting
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Targeting glycan-binding receptors is an attractive strategy for cell-specific drug and gene delivery. The C-type lectin asialoglycoprotein receptor (ASGPR) is particularly suitable for liver-specific delivery due to its exclusive expression by parenchymal hepatocytes. In this study, we designed and developed an efficient synthesis of carbohydrate-functionalized β-cyclodextrins (βCDs) and liposomes for hepatocyte-specific delivery. For targeting of ASGPR, rhodamine B-loaded βCDs were functionalized with glycodendrimers. Liposomes were equipped with synthetic glycolipids containing a terminal d-GalNAc residue to mediate binding to ASGPR. Uptake studies in the human hepatocellular carcinoma cell line HepG2 demonstrated that βCDs and liposomes displaying terminal d-Gal/d-GalNAc residues were preferentially endocytosed. In contrast, uptake of βCDs and liposomes with terminal d-Man or D-GlcNAc residues was markedly reduced. The d-Gal/d-GalNAc-functionalized βCDs and liposomes presented here enable hepatocyte-specific targeting. Gal-functionalized βCDs are efficient molecular carriers to deliver doxorubicin in vitro into hepatocytes and induce apoptosis.
- Bernardes, Gonalo J. L.,Kikkeri, Raghavendra,Maglinao, Maha,Laurino, Paola,Collot, Mayeul,Hong, Sung You,Lepenies, Bernd,Seeberger, Peter H.
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- De novo design of a trans-β-N-acetylglucosaminidase activity from a GH1 β-glycosidase by mechanism engineering
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Glycoside hydrolases are particularly abundant in all areas of metabolism as they are involved in the degradation of natural polysaccharides and glycoconjugates. These enzymes are classified into 133 families (CAZy server, http://www.cazy.org) in which members of each family have a similar structure and catalytic mechanism. In order to understand better the structure/function relationships of these enzymes and their evolution and to develop new robust evolved glycosidases, we undertook to convert a Family 1 thermostable β-glycosidase into an exo-β-N-acetylglucosaminidase. This latter activity is totally absent in Family 1, while natural β-hexosaminidases belong to CAZy Families 3, 20 and 84. Using molecular modeling, we first showed that the docking of N-acetyl-d-glucosamine in the subsite -1 of the β-glycosidase from Thermus thermophilus (TtβGly) suggested several steric conflicts with active site amino-acids (N163, E338) induced by the N-acetyl group. Both N163A and N163D-E338G mutations induced significant N-acetylglucosaminidase activity in TtβGly. The double mutant N163D-E338G was also active on the bicyclic oxazoline substrate, suggesting that this mutated enzyme uses a catalytic mechanism involving a substrate-assisted catalysis with a noncovalent oxazoline intermediate, similar to the N-acetylglucosaminidases from Families 20 and 84. Furthermore, a very efficient trans-N-acetylglucosaminidase activity was observed when the double mutant was incubated in the presence of NAG-oxazoline as a donor and N-methyl-O-benzyl-N-(β-d-glucopyranosyl)-hydroxylamine as an acceptor. More generally, this work demonstrates that it is possible to exchange the specificities and catalytic mechanisms with minimal changes between phylogenetically distant protein structures.
- André-Miral, Corinne,Koné, Fankroma Mt,Solleux, Claude,Grandjean, Cyrille,Dion, Michel,Tran, Vinh,Tellier, Charles
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- A silyl ether-protected building block forO-GlcNAcylated peptide synthesis to enable one-pot acidic deprotection
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In this report, we introduce a novel building block for Fmoc/tBu solid phase peptide synthesis (SPPS) of β-linkedO-GlcNAcylated peptides. This building block carries acid labile silyl ether protecting groups, which are fully removed under TFA-mediated peptide cleavage conditions from the resin, thus requiring fewer synthetic steps and no intermediate purification as compared to other acid or base labile protecting group strategies.
- Yan, Bingjia,Li, Wenyi,Hackenberger, Christian P. R.
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supporting information
p. 8014 - 8017
(2021/10/04)
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- Synthesis method of tetrahydropyrano [3, 2-d] oxazole ring compound
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The invention discloses a tetrahydropyrano [3, 2d] oxazole ring compound and a synthesis method thereof.The synthesis method includes the following steps that a sealed container A and a sealed container B are designed, the tops of the two sealed containers are communicated through a guide pipe, 2-acetamido-2-deoxy-D-pyranose protected by a protecting group is added into the container A, - and 1, 1-sulfonyldiimidazole andpotassium fluoride are added into the container B, dichloromethane and triethylamine are injected into the container A, and trifluoroacetic acid is injected into the containerB, sulfuryl fluoride gas is generated in situ in the container B, the sulfuryl fluoride gas is introduced into the container A through a conduit, stirring and reacting are carried out in the containerA, reduced pressure spin-drying is carried out after the reaction is completed, and silica gel rapid column chromatography separation is carried out to obtain the target compound. The process for preparing the tetrahydropyrano [3, 2-d] oxazole ring compound is simple, the yield of the target compound is high, and the substrate range is wide. And the reaction can be carried out at normal temperature, and the method is simple, convenient to operate and suitable for conventional preparation.
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Paragraph 0017-0018
(2021/01/15)
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- Dual-participation protecting group solves the anomeric stereocontrol problems in glycosylation reactions
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The 2,2-dimethyl-2-(ortho-nitrophenyl)acetyl (DMNPA) group permits, via robust neighboring group participation (NGP) or long distance participation (LDP) effects, the stereocontrolled 1,2-trans, 1,2-cis, as well as β-2,6-dideoxy glycosidic bond generation, while suppressing the undesired orthoester byproduct formation. The robust stereocontrol capability of the DMNPA is due to the dual-participation effect from both the ester functionality and the nitro group, verified by control reactions and DFT calculations and further corroborated by X-ray spectroscopy.
- Liu, Hui,Hansen, Thomas,Zhou, Si-Yu,Wen, Guo-En,Liu, Xu-Xue,Zhang, Qing-Ju,Codeé, Jeroen D. C.,Schmidt, Richard R.,Sun, Jian-Song
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supporting information
p. 8713 - 8717
(2019/10/28)
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- Chemoenzymatic Synthesis of Glycoconjugates Mediated by Regioselective Enzymatic Hydrolysis of Acetylated 2-Amino Pyranose Derivatives
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Highly regioselective deprotection of a series of 2-amino pyranose building blocks was achieved by enzymatic hydrolysis. These monodeprotected intermediates were successfully used in the synthesis of a variety of glycoconjugate derivatives with a core of glucosamine or galactosamine, including neo-glycoproteins and glycosphingolipids. The hydrolysis catalyzed by acetylxylan esterase from Bacillus pumilus (AXE) is suitable for the synthesis of neo-glycoproteins with an N-acetyl glucosamine core. The hydrolysis catalyzed by Candida rugosa lipase (CRL) was successfully applied in the preparation of new sialylated glycolipids starting from glucosamine building blocks protected as phthalimide. This chemoenzymatic approach can be used for the preparation of new glycoconjugate products with anticancer activity.
- Zheng, Changping,Bavaro, Teodora,Tengattini, Sara,Mascherpa, Andrea Gualla,Sollogoub, Matthieu,Zhang, Yongmin,Terreni, Marco
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supporting information
p. 3622 - 3631
(2019/06/17)
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- COMPOSITIONS AND METHODS FOR INDUCING IMMUNE TOLERANCE
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Several embodiments provided in the present disclosure relate to compositions that carry an antigen to which tolerance is desired, the antigen being coupled, bound, or otherwise joined to a targeting moiety, the targeting moiety configured to direct the composition to the liver of a subject. In several embodiments, the antigen in coupled to the targeting moiety by way of a polymeric linker. In several embodiments, the polymeric linker is configured to liberate the antigen in vivo. Methods of using the compositions to reduce and/or prevent unwanted immune responses against an antigen of interest are also provided.
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Paragraph 0311; 0312
(2019/01/08)
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- Glycosyl Aldehydes: New Scaffolds for the Synthesis of Neoglycoconjugates via Bioorthogonal Oxime Bond Formation
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The straightforward preparation of glycosyl neoconjugates by oxime (or hydrazone) bond formation represents a key bioorthogonal tool in chemical biology. However, when this strategy is employed by reacting the reducing end of the glycan moiety, the configuration and the stereochemical information is lost due to partial (or complete) opening of the glycan cyclic hemiacetal and the formation of the corresponding opened tautomers. We have completed the synthesis of a library of glycosyl aldehydes to be used as scaffold for the synthesis of neoglycoconjugates via oxime bond formation. These glycosyl aldehydes constitute a simple and accessible alternative to avoid loss of chiral information when conjugating, by oxime (or hydrazone) bonds, the aldehyde functionality present at the reducing end of natural carbohydrates.
- Reina, José J.,Rioboo, Alicia,Montenegro, Javier
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p. 831 - 845
(2018/01/11)
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- ENDOSOMAL CLEAVABLE LINKERS
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The present disclosure relates generally to cleavable linkers and uses thereof.
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Paragraph 00565
(2018/08/20)
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- SILICON PARTICLES TARGETING TUMOR CELLS
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A silicon particle comprising a silicon body, a functionalized silica surface surrounding the silicon body, and a targeting moiety specifically targeting tumor cells, and, optionally, an enzymatically metabolizable compound,is useful in the treatment of cancer by producing cell death after particle internalization.
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Page/Page column 55
(2015/12/08)
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- Synthesis of anti-inflammatory α-and β-linked acetamidopyranosides as inhibitors of toll-like receptor 4 (TLR4)
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Abstract The low-molecular weight isopropyl 2-acetamido-α-glucoside 16 (C34) inhibits toll-like receptor 4 (TLR4) in enterocytes and macrophages in vitro, and reduces systemic inflammation in mouse models of endotoxemia and necrotizing enterocolitis. We used a copper(II)-mediated solvolysis of anomeric oxazolines and an acid-mediated conversion of β-glucosamine and β-galactosamine pentaacetates to generate analogs of 16 at the anomeric carbon and at C-4 of the pyranose ring. These compounds were evaluated for their influence on TLR4-mediated inflammatory signaling in cultured enterocytes and monocytes. Their efficacy was confirmed using a NF-kB-luciferase reporter mouse, thus establishing the first structure-activity relationship (SAR) study in this series and identifying the more efficacious isopropyl 2-acetamido-α-galactoside 17.
- Wipf, Peter,Eyer, Benjamin R.,Yamaguchi, Yukihiro,Zhang, Feng,Neal, Matthew D.,Sodhi, Chhinder P.,Good, Misty,Branca, Maria,Prindle, Thomas,Lu, Peng,Brodsky, Jeffrey L.,Hackam, David J.
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supporting information
p. 3097 - 3100
(2015/06/02)
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- Nucleophilic Aromatic Substitution (SNAr) as an Approach to Challenging Carbohydrate-Aryl Ethers
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A general and practical route to carbohydrate-aryl ethers by nucleophilic aromatic substitution (SNAr) is reported. Upon treatment with KHMDS, C-O bond formation occurs between carbohydrate alcohols and a diverse range of fluorinated (hetero)ar
- Henderson, Alexander S.,Medina, Sandra,Bower, John F.,Galan, M. Carmen
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supporting information
p. 4846 - 4849
(2015/10/12)
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- Glycosylation with 2-Acetamido-2-deoxyglycosyl Donors at a Low Temperature: Scope of the Non-Oxazoline Method
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A direct construction of 1,2-trans-β-linked 2-acetamido-2-deoxyglycosides was investigated. The 3,4,6-tri-O-benzyl- and 3,4,6-tri-O-acetyl-protected glycosyl diethyl phosphites and 4,6-O-benzylidene-protected galactosyl diethyl phosphite each reacted with
- Arihara, Ryoichi,Kakita, Kosuke,Suzuki, Noritoshi,Nakamura, Seiichi,Hashimoto, Shunichi
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p. 4259 - 4277
(2015/05/13)
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- CARBOHYDRATE-BASED COMPOSITIONS AND METHODS FOR TARGETED DRUG DELIVERY
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Provided herein are compositions and methods for intracellular delivery. The compositions are polymer compositions in which the polymer serves as a carrier for therapeutic and/or diagnostic agents. The polymer compositions are effective in targeted delivery of therapeutic and/or diagnostic agents to a cell. The polymer compositions include a targeting moiety that includes carbohydrate groups that effectively target specific cell surface receptors. The polymer compositions also include an agent binding moiety that effectively associates the therapeutic and/or diagnostic agent to be delivered to the cell.
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Paragraph 0155
(2014/09/03)
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- OGlcNAcylation and phosphorylation have opposing structural effects in tau: Phosphothreonine induces particular conformational order
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Phosphorylation and OGlcNAcylation are dynamic intracellular protein post-translational modifications that frequently are alternatively observed on the same serine and threonine residues. Phosphorylation and OGlcNAcylation commonly occur in natively disordered regions of proteins, and often have opposing functional effects. In the microtubule-associated protein tau, hyperphosphorylation is associated with protein misfolding and aggregation as the neurofibrillary tangles of Alzheimer's disease, whereas OGlcNAcylation stabilizes the soluble form of tau. A series of peptides derived from the proline-rich domain (residues 174-251) of tau was synthesized, with free Ser/Thr hydroxyls, phosphorylated Ser/Thr (pSer/pThr), OGlcNAcylated Ser/Thr, and diethylphosphorylated Ser/Thr. Phosphorylation and OGlcNAcylation were found by CD and NMR to have opposing structural effects on polyproline helix (PPII) formation, with phosphorylation favoring PPII, OGlcNAcylation opposing PPII, and the free hydroxyls intermediate in structure, and with phosphorylation structural effects greater than OGlcNAcylation. For tau196-209, phosphorylation and OGlcNAcylation had similar structural effects, opposing a nascent α-helix. Phosphomimic Glu exhibited PPII-favoring structural effects. Structural changes due to Thr phosphorylation were greater than those of Ser phosphorylation or Glu, with particular conformational restriction as the dianion, with mean 3JαN = 3.5 Hz (pThr) versus 5.4 Hz (pSer), compared to 7.2, 6.8, and 6.2 Hz for Thr, Ser, and Glu, respectively, values that correlate with the backbone torsion angle. Dianionic phosphothreonine induced strong phosphothreonine amide protection and downfield amide chemical shifts (δmean = 9.63 ppm), consistent with formation of a stable phosphate-amide hydrogen bond. These data suggest potentially greater structural importance of threonine phosphorylation than serine phosphorylation due to larger induced structural effects.
- Brister, Michael A.,Pandey, Anil K.,Bielska, Agata A.,Zondlo, Neal J.
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supporting information
p. 3803 - 3816
(2014/04/03)
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- Rationally designed short polyisoprenol-linked PglB substrates for engineered polypeptide and protein N-glycosylation
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The lipid carrier specificity of the protein N-glycosylation enzyme C. jejuni PglB was tested using a logical, synthetic array of natural and unnatural C10, C20, C30, and C40 polyisoprenol sugar pyrophosphates, including those bearing repeating cis-prenyl units. Unusual, short, synthetically accessible C20 prenols (nerylnerol 1d and geranylnerol 1e) were shown to be effective lipid carriers for PglB sugar substrates. Kinetic analyses for PglB revealed clear KM-only modulation with lipid chain length, thereby implicating successful in vitro application at appropriate concentrations. This was confirmed by optimized, efficient in vitro synthesis allowing >90% of Asn-linked β-N-GlcNAc-ylated peptide and proteins. This reveals a simple, flexible biocatalytic method for glycoconjugate synthesis using PglB N-glycosylation machinery and varied chemically synthesized glycosylation donor precursors.
- Liu, Feng,Vijayakrishnan, Balakumar,Faridmoayer, Amirreza,Taylor, Thomas A.,Parsons, Thomas B.,Bernardes, Goncalo J.L.,Kowarik, Michael,Davis, Benjamin G.
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supporting information
p. 566 - 569
(2014/02/14)
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- Glycosylated derivatives of substituted hydroxylamine. II. the phase transfer synthesis and the study of the glycosyl transfer reaction of glucosaminides of substituted hydroxylamine
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The interaction of 1-(2-acetamido-3,4,6,-tri-O-acetyl-2-deoxy-β-D- glucopyranosyloxy)benzotriazole with primary and secondary aliphatic and cycloaliphatic alcohols or diisopropylidenegalactose in refluxing methylene chloride under the catalysis of Lewis a
- Kuryanov,Luschtshyk,Chupakhina
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p. 426 - 433
(2013/08/23)
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- NaBH3CN and other systems as substitutes of tin and silicon hydrides in the light or heat-initiated reduction of halosugars: A tunable access to either 2-deoxy sugars or 1,5-anhydro-itols
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UV light-promoted reduction of acetobromoglucose by NaBH3CN in t-BuOH afforded 1,3,4,6-tetra-O-acetyl-2-deoxy-α-d-arabino-hexopyranose in high yield and purity, via a Surzur-Tanner rearrangement, while, with 10 mol % thiophenol added, acetylated 1,5-anhydro-d-glucitol was cleanly obtained. Such tin-free and mild reductions, presumed to proceed via radical pathways, were more efficient with NaBH3CN compared to NaBH4 or NaBD 4, and do not occur with acetochloroglucose. Similar reductions to 1,3,4,6-tetra-O-acetyl-2-deoxy-α-d-arabino-hexopyranose were achieved upon heating to 80 C t-BuOH or CH3CN solutions of NaBH3CN and AIBN, but with a lower selectivity due to competing ionic reactions. With other pyranosyl bromides, reductions by NaBH3CN could be tuned similarly (d-galacto), but some (d-manno, 5-thio-d-xylo) gave mainly or exclusively 1,5-anhydro-itols. Other conditions, or reagents promoting SET process, afforded also reduced products, but with lower rates or selectivities. Primary iodides were reduced readily with NaBH3CN under UV light.
- Bruyère, Isabelle,Tóth, Zoltan,Benyahia, Hamida,Xue, Jia Lu,Praly, Jean-Pierre
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supporting information
p. 9656 - 9662
(2013/10/22)
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- Specific features of phase transfer catalytic glycosylation of aromatic hydroxy acids
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Reactions of peracetylated α-D-glucosaminyl chloride with isomeric hydroxybenzoic and 1-hydroxy-2-naphthoic acids in a solid phase transfer system of potassium carbonate-acetonitrile were studied. It was found that the nature of carboxylic acids, lipophilicity of the phase transfer catalyst, and reaction temperatures affected the reaction composition and product yields. The O-β-glycosyl esters of ortho-hydroxyaromatic acids were first found to form anomeric 1,2-cis derivatives in the presence of potassium carbonate. The structures of the synthesized compounds were confirmed by 1H NMR spectroscopy. As was shown in vivo experiments, the analgesic activities of glycosyl esters of salicylic acid and peracetylated 2-carboxyphenylglucosaminide were comparable with that of aspirin.
- Chupakhina,Astrakhantseva,Kuryanov
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p. 306 - 311
(2013/07/27)
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- Stereoselective synthesis of β-glycosyl thiols and their synthetic applications
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A significantly fast reaction condition for the exclusive preparation β-glycosyl thiol derivatives has been developed successfully. The reaction condition is one-step, fast, high yielding, highly stereoselective, and requires only benchtop chemicals. Further reaction of glycosyl thiol derivatives with Michael acceptors and alkylating agents furnished thioglycosides and (1,1)-thiolinked trehalose analogs.
- Jana, Manas,Misra, Anup Kumar
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p. 2680 - 2686
(2013/04/24)
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- Preparation of carbohydrate arrays by using Diels-Alder reactions with inverse electron demand
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Carbohydrate microarrays are an emerging tool for the high-throughput screening of carbohydrate-protein interactions that represent the basis of many biologically and medicinally relevant processes. The crucial step in the preparation of carbohydrate arrays is the attachment of carbohydrate probes to the surface. We examined the Diels-Alder reaction with inverse-electron-demand (DARinv) as an irreversible, chemoselective ligation reaction for that purpose. After having shown the efficiency of the DARinv in solution, we prepared a series of carbohydrate-dienophile conjugates that were printed onto tetrazine-modified glass slides. Binding experiments with fluorescently labeled lectins proved successful and homogeneous immobilization was achieved by the DARinv. For immobilization of nonfunctionalized reducing oligosaccharides we developed a bifunctional chemoselective linker that enabled the attachment of a dienophile tag to the oligosaccharides through oxime ligation. The conjugates obtained were successfully immobilized on glass slides. The presented strategies for the immobilization of both synthetic carbohydrate derivatives and unprotected reducing oligosaccharides facilitate the preparation of high-quality carbohydrate microarrays by means of the chemoselective DARinv. This concept can be readily adapted for the preparation of other biomolecule arrays. Copyright
- Beckmann, Henning S. G.,Niederwieser, Andrea,Wiessler, Manfred,Wittmann, Valentin
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supporting information; scheme or table
p. 6548 - 6554
(2012/06/30)
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- Facile synthesis of nitrophenyl 2-acetamido-2-deoxy-α-D- mannopyranosides from ManNAc-oxazoline
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The synthetic procedures for a large-scale preparation of o- and p-nitrophenyl 2-acetamido-2-deoxy-α-D-mannopyranoside are described. The synthetic pathway employs the glycosylation of phenol with ManNAc oxazoline, followed by nitration of the aromatic moiety yielding a separable mixture of the o- and p-nitrophenyl derivative in a 2:3 ratio.
- Krenek, Karel,Simon, Petr,Weignerova, Lenka,Fliedrova, Barbora,Kuzma, Marek,Kren, Vladimir
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scheme or table
p. 428 - 432
(2012/05/05)
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- Preparation of oligosaccharides by homogenous enzymatic synthesis and solid phase extraction
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This communication describes a method for enzymatic preparation of bioactive glycans, which integrated the high-efficiency of homogenous phase enzymatic reaction and fast separation of solid phase extraction.
- Wang, Wenjun,Jin, Chen,Guo, Lina,Liu, Yu,Wan, Yue,Wang, Xin,Li, Lei,Zhao, Wei,Wang, Peng George
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supporting information; experimental part
p. 11240 - 11242
(2011/12/05)
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- Straightforward synthesis of 2-acetamido-2-deoxy -β- d -glucopyranosyl esters under microwave conditions
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A straightforward synthesis of 2-acetamido-2-deoxy -β-d-glucopyranosyl esters from unprotected GlcNAc oxazoline has been achieved under catalyst-free, microwave conditions. Georg Thieme Verlag Stuttgart New York.
- Haddoub, Rose,Laurent, Nicolas,Meloni, Marco M.,Flitsch, Sabine L.
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experimental part
p. 3328 - 3332
(2010/03/03)
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- Synthesis of heteroaromatic N-β-glycosides of N-acetylglucosamine under phase transfer conditions: II. Indolin-2-one glycosaminides
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Regioselective N-β-glucosamination of various unsubstituted or C4-, C5-, or C6-monosubstituted indolin-2-ones under phase transfer conditions was studied. The regioselectivity was unambiguously proved by 1H NMR spectroscopy and X-ray analysis. The presence of substituent at C7 of the aromatic ring leads to the formation of either a mixture of isomeric N-β-and O-β-D-glucosaminides, or only oxazoline and/or 2-acetamidoglycal irrespective of the reaction conditions.
- Kur'yanov,Chupakhina,Shishkin,Shishkina,Chirva
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experimental part
p. 730 - 738
(2009/04/12)
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- The anomeric Pudovik rearrangement
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The O,O-dibenzyl-S-glycosyl phosphothioite derived from 3,4,6-tri-O-acetyl-2-acetamido-2-deoxy-1-thio-α-d-glucopyranose rearranges under the influence of triethylborane and air to provide the corresponding 1-C-pyranosyl-O,O-dibenzylphosphonothioate, a new
- Knapp, Spencer,Ajayi, Kehinde
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p. 1945 - 1949
(2007/10/03)
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- Microwave-assisted glycosylation for the synthesis of glycopeptides
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An efficient one-step synthesis of O-linked glycosylamino acids is described. This methodology converts commercially available peracetylated mono- and disaccharides activated by cheap and environmentally safe FeCl3 under microwave irradiation w
- Seibel, Juergen,Hillringhaus, Lars,Moraru, Roxana
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p. 507 - 511
(2007/10/03)
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- Elimination reactions of glycosyl selenoxides
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Glycosyl selenoxides, generated in situ from selenoglycosides by a Sharpless-type oxidation, undergo facile syn elimination leading to 2-hydroxy and 2-amino glycals in high yield. Graphical abstract.
- Chambers, David J.,Evans, Graham R.,Fairbanks, Antony J.
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p. 8411 - 8419
(2007/10/03)
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- PROCESS FOR PRODUCTION OF SACCHARIDE OXAZOLINE DERIVATIVES
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A method for production of a sugar oxazoline derivative represented by the following general formula (2), comprising the step of:reacting an acylamino sugar represented by the following general formula (1) with a metal fluoride; ???wherein X is selected from F, Cl, Br, and I; ???R1 is selected from H and (CH2)n-CH3 wherein n = 0 to 5; ???R2, R3, R4, R5, and R6 are each independently selected from H, N3, OH protected by a protective group, NH2 protected by a protective group, and Y-R7 wherein Y is O, NH, or S; and R7 is a mono- or oligo-saccharide residue, with the proviso that when the residue bears OH, NH2, or COOH, the groups are protected by protective groups, provided that at least one of R2 and R3 and at least one of R4 and R5 are each H; ???wherein R1, R2, R3, R4, R5, and R6 are the same as those mentioned above.
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- Synthesis and biological activities of lipid A analogs possessing β-glycosidic linkage at 1-position
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New lipid A analogs having acidic groups β-glycosidically linked at the 1-position were synthesized in order to investigate the structural requirement for immunostimulating and endotoxic activity of lipid A. The β-(phosphonoxy)ethyl (PE) and carboxymethyl (CM) analogs of Escherichia coli type having six acyl groups and those of the biosynthetic precursor type having four acyl groups were synthesized via a divergent synthetic route. The E. coli type β-(phosphonoxy)-ethyl analog, which was previously reported to be not endotoxic, showed strong immunostimulating activity comparable to the natural-type α-analog. The acidic functional groups are concluded to be essential but their strict spatial arrangement is not required for expression of the biological activity.
- Fukase, Koichi,Ueno, Atsushi,Fukase, Yoshiyuki,Oikawa, Masato,Suda, Yasuo,Kusumoto, Shoichi
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p. 485 - 500
(2007/10/03)
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- Galacto, Gluco, Manno, and Disaccharide-Based C-Glycosides of 2-Amino-2-deoxy Sugars
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(Matrix Presented) Starting from readily available precursors, selenoglycosides derived from GalNAc, GlcNAc, and ManNAc were prepared by either a one- or a two-step process. The anomeric selenides underwent facile C-Se homolysis to provide the correspondi
- Grant, Laura,Liu, Yan,Walsh, Kenneth E.,Walter, Daryl S.,Gallagher, Timothy
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p. 4623 - 4625
(2007/10/03)
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- Copper(II)-mediated activation of sugar oxazolines: Mild and efficient synthesis of β-glycosides of N-acetylglucosamine
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2-Methyl-(3,4,6-tri- O-acetyl- 1,2-dideoxy-α-D-glucopyrano)-[2,1-d]-2-oxazoline (5) was reacted with glycosyl acceptors bearing primary (6, 8, 10, 20) or secondary hydroxy groups (12, 14, 16, 18) in the presence of anhydrous cupric bromide or cupric chloride at elevated temperature to provide 2-acet-amido-2-deoxy-β-D-glucopyranosides in 36-92% yield. The reaction conditions are milder than those previously described for oxazoline activation employing p-toluenesulfonic acid or ferric chloride. Treatment of the oxazoline with trimethylsilyl azide (22) and CuCl2 leads to 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-β-D-glucopyranosyl azide (23) in 69% yield. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002).
- Wittmann, Valentin,Lennartz, Dirk
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p. 1363 - 1367
(2007/10/03)
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- A facile method for synthesis of 1,2-oxazoline derivative of N-acetylglucosamine promoted by potassium fluoride
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A potassium fluoride-promoted intramolecular cyclization reaction of 2-acetamido-2-deoxy-α-D-glucopyranosyl chloride took place smoothly, giving the corresponding 1,2-oxazoline derivative in good yield. Potassium fluoride behaves as a nucleophile for anomerization of the glycosyl chloride as well as an acid captor to scavenge the protonic acid liberated. This is an extremely practical method for preparation of sugar oxazoline derivatives with simple experimental procedures.
- Shoda, Shin-Ichiro,Izumi, Ryuko,Suenaga, Masako,Saito, Kenji,Fujita, Masaya
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p. 150 - 151
(2007/10/03)
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- Linear synthesis of a protected H-type II pentasaccharide using glycosyl phosphate building blocks
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A linear synthesis of a fully protected H-type II blood group determinant pentasaccharide utilizing glycosyl phosphate and glycosyl trichloroacetimidate building blocks is reported. Envisioning an automated solid-phase synthesis of blood group determinants, the utility of glycosyl phosphates in the stepwise construction of complex oligosaccharides, such as the H-type II antigen, is demonstrated. Installation of the central glucosamine building block required the screening of a variety of nitrogen protecting groups to ensure good glucosamine donor reactivity and protecting group compatibility. The challenge to differentiate C2 of the terminal galactose in the presence of other hydroxyl and amine protecting groups prompted us to introduce the 2-(azidomethyl)benzoyl group as a novel mode of protection for carbohydrate synthesis. The compatibility of this group with traditionally employed protecting groups was examined, as well as its use as a C2 stereodirecting group in glycosylations. The application of the 2-(azidomethyl)benzoyl group along with a systematic evaluation of glycosyl donors allowed for the completion of the pentasaccharide and provides a synthetic strategy that is expected to be generally amenable to the solid support synthesis of blood group determinants.
- Love, Kerry Routenberg,Andrade, Rodrigo B.,Seeberger, Peter H.
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p. 8165 - 8176
(2007/10/03)
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- Chemical synthesis of N-acetylglucosamine derivatives and their use as glycosyl acceptors by the Mesorhizobium loti chitin oligosaccharide synthase NodC
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Rhizobial bacteria synthesize lipo-chitin oligosaccharide signal molecules (Nod factors) that are essential for the formation of symbiotic organs on the roots of host plants, a process known as nodulation. Biosynthesis of the chitin oligosaccharide moiety
- Kamst, Eric,Zegelaar-Jaarsveld, Korien,Van Der Marel, Gijs A.,Van Boom, Jacques H.,Lugtenberg, Ben J.J.,Spaink, Herman P.
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p. 176 - 189
(2007/10/03)
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- Use of sodium iodide and crown ether in the synthesis of N-acetylglucosamine glycosides
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A pair of sodium iodide-crown ether reagents was used in the synthesis of N-acetylglucosamine glycosides. At room temperature, the reaction resulted in β-glycosides, whereas at 85-90°C, it gave a mixture of anomers or α-anomer only.
- Kur'yanov,Zemlyakov,Chupakhina,Chirva
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p. 282 - 283
(2007/10/03)
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- Stereocontrolled allylation of 2-amino-2-deoxy sugar derivatives by a free-radical procedure
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Preparative routes for anomerically specific 1-C-allylation of 2-amino-2-deoxy sugars have been evaluated in a comparative study of various N-substituents and aglycons as precursors for glycosyl radicals that effectively capture an allyl group from allylt
- Cui, Jingrong,Horton, Derek
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p. 319 - 330
(2007/10/03)
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- Chemoenzymatic synthesis of a characteristic phosphorylated and glycosylated peptide fragment of the large subunit of mammalian RNA polymerase II
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The covalent modification of proteins by phosphorylation and addition of GlcNAc residues are important regulatory processes which mediate biological signal transduction. For instance, the cytosolic form of RNA polymerase II is heavily glycosylated but dur
- Pohl, Torsten,Waldmann, Herbert
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p. 6702 - 6710
(2007/10/03)
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- Synthesis of the glucoallosamidin pseudo-disaccharide: Use of an efficient Hg(II) mediated cyclization
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The title compound 1a was prepared from cyclopentadienylthallium in 11 steps. The key component of the pseudo-disaccharide 1a, (-)-allosamizoline 2, was synthesized in 2 steps starting from the known cyclopentene 4 by formation of the aminoimidate 5 follo
- Shrader, William D.,Imperiali, Barbara
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p. 599 - 602
(2007/10/02)
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