- Synthesis and evaluation of a series of 6-chloro-4-methylumbelliferyl glycosides as fluorogenic reagents for screening metagenomic libraries for glycosidase activity
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Screening of large enzyme libraries such as those derived from metagenomic sources requires sensitive substrates. Fluorogenic glycosides typically offer the best sensitivity but typically must be used in a stopped format to generate good signal. Use of fluorescent phenols of pKa 7, such as halogenated coumarins, allows direct screening at neutral pH. The synthesis and characterisation of a set of nine different glycosides of 6-chloro-4-methylumbelliferone are described. The use of these substrates in a pooled format for screening of expressed metagenomic libraries yielded a "hit rate" of 1 in 60. Hits were then readily deconvoluted with the individual substrates in a single plate to identify specific activities within each clone. The use of such a collection of substrates greatly accelerates the screening process.
- Chen, Hong-Ming,Armstrong, Zachary,Hallam, Steven J.,Withers, Stephen G.
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- Synthese und 1H-NMR-Studie der vier unverzweigten peracetylierten β-D-Glucopyranosyl-β-gentiobiosen
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With regard to the structure elucidation of an unknown trisaccharide isolated from the stigmas of garden crocusses (Crocus neapolitanus var.), the four unbranched (1->6)-, (1->4)-, (1->3)-, and (1->2)-connected β-D-glucopyranosyl-β-gentiobiose peracetates were synthesized.A complete analysis of the 1H-NMR spectra of the four trisaccharide peracetates was carried out.
- Rychener, Martin,Bigler, Peter,Pfander, Hanspeter
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- Design and synthesis of hydrolytically stable multivalent ligands bearing thiodigalactoside analogues for peanut lectin and human galectin-3 binding
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Herein, we describe the design and synthesis of a novel family of hydrolytically stable glycoclusters bearing thiodigalactoside (TDG) analogues as recognition elements of β-galactoside binding lectins. The TDG analogue was synthesized by thioglycosylation of a 6-S-acetyl-α-d-glucosyl bromide with the isothiouronium salt of 2,3,4,6-tetra-O-acetyl-β-d-galactose. Further propargylation of the TDG analogue allowed the coupling to azido-functionalized oligosaccharide scaffolds through copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) under microwave activation. The final mono-, di-, and tetravalent ligands were resistant to enzymatic hydrolisis by Escherichia coli β-galactosidase. Binding affinities to peanut agglutinin and human galectin-3 were measured by isothermal titration calorimetry which showed Ka constants in the micromolar range as well as a multivalent effect. Monovalent ligand exhibited a binding affinity higher than that of thiodigalactoside. Docking studies performed with a model ligand on both β-galactoside binding lectins showed additional interactions between the triazole ring and lectin amino acid residues, suggesting a positive effect of this aromatic residue on the biological activity.
- Cagnoni, Alejandro J.,Kovensky, José,Uhrig, María Laura
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- p-Aminophenyl 1-thio-β-D-cellobioside: Synthesis and application in affinity chromatography of exo-type cellulases
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p-Aminophenyl 1-thio-β-D-cellobioside (APTC) is shown to be a functional affinity ligand for the separation of exo-(cellobiohydrolases) and endo-(endoglucanases) acting cellulases. APTC is prepared by direct attachment of p-aminobenzenethiol to 2,3,6-tri-O-acetyl-4-O-(2,3,4,6-tetra-O-acetyl-β-D-glucopy-ranosyl)-β-D -glucopyranosyl bromide, and subsequent deacetylation. APTC has been coupled to N-hydroxysuccinimide-activated agarose for affinity chromatography. Trichoderma reesei cellulases were used as representative enzymes. The behavior of these enzymes on APTC-affinity columns was essentially equivalent to that reported for the same enzymes on p-aminobenzyl 1-thio-β-D-cellobioside (ABTC)-columns; ABTC being the traditional ligand for affinity chromatography of exocellulase. The major cellobiohydrolases are retained on these columns, whereas the major endoglucanases are not. The cellobiohydrolases may be eluted from the columns by the addition of cellobiose to the mobile phase. The primary advantage of the APTC-ligand over other affinity ligands is its ease of preparation; the preparation of APTC requires approximately one-half the number of synthetic steps as required for the preparation of ABTC.
- Piyachomkwan, Kuakoon,Gable, Kevin P.,Penner, Michael H.
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- Versatile and mild synthesis of Di- and trisaccharidic 2-enopyranosyl cyanides by cyanation of per-O-acetylglycals with trimethylsilyl cyanide catalyzed by palladium(II) acetate
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A catalytic amount (1-2 mol%) of palladium(II) acetate was found to work as a catalyst for the cyanation of di- and trisaccharidic per-O-acetylglycals with trimethylsilyl cyanide to afford di- and trisaccharidic 2-enopyranosyl cyanides in high yields and in moderate stereoselectivities. Georg Thieme Verlag Stuttgart.
- Xu, Xiaoyong,Tan, Qitao,Hayashi, Masahiko
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- Excited-State Palladium-Catalyzed Radical Migratory Mizoroki-Heck Reaction Enables C2-Alkenylation of Carbohydrates
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Excited-state palladium catalysis has emerged as a promising strategy for developing novel and valuable reactions. Herein, we report the first excited-state Pd-catalyzed 1,2-radical migratory Mizoroki-Heck reaction that enables C2-alkenylation of carbohydrates using readily available 1-bromosugars and alkenes. The reaction tolerates a wide variety of functional groups and complex molecular architectures, including derivatives of natural products and marketed drugs. Preliminary mechanistic studies and DFT calculations suggest the involvement of visible-light-induced photoexcitation of Pd species, 1,2-spin-centered-shift (SCS) process, and Heck-type cross-coupling reaction. The reaction expands the reactivity profile of excited-state Pd catalysis and provides a streamlined protocol for the preparation of a wide variety of C2-alkenylated carbohydrate mimetics to aid the discovery and development of new therapeutics, agrochemicals, and materials.
- Liu, Peng,Mukherjee, Upasana,Ngai, Ming-Yu,Wu, Yue,Yao, Wang,Zhao, Gaoyuan,Zhou, Lin
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supporting information
p. 3353 - 3359
(2022/03/08)
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- Synthesis and biological evaluation of 3β-O-neoglycosides of caudatin and its analogues as potential anticancer agents
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In order to study the structure–activity relationship (SAR) of C21-steroidal glycosides toward human cancer cell lines and explore more potential anticancer agents, a series of 3β-O-neoglycosides of caudatin and its analogues were synthesized. The results revealed that most of peracetylated 3β-O-monoglycosides demonstrated moderate to significant antiproliferative activities against four human cancer cell lines (MCF-7, HCT-116, HeLa, and HepG2). Among them, 3β-O-(2,3,4-tri-O-acetyl-β-L-glucopyranosyl)-caudatin (2k) exhibited the highest antiproliferative activity aganist HepG2 cells with an IC50 value of 3.11 μM. Mechanical studies showed that compound 2k induced both apoptosis and cell cycle arrest at S phase in a dose dependent manner. Overall, these present findings suggested that glycosylation is a promising scaffold to improve anticancer activity for naturally occurring C21-steroidal aglycones, and compound 2k represents a potential anticancer agent deserved further investigation.
- Li, Xiao-San,Chen, Tang-Ji,Xu, Zhi-Peng,Long, Juan,He, Miao-Ying,Zhan, He-Hui,Zhuang, Hai-Cai,Wang, Qi-Lin,Liu, Li,Yang, Xue-Mei,Tang, Jin-Shan
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- Halogenation and anomerization of glycopyranoside by TESH/bromine and BHQ/bromine
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Treatment of peracetylated glycosides and β-isopropyl glycosides with halogen in the presence of TESH and BHQ has been found to result in the halogenation and the anomerization, respectively. Peracetylatedglycosides treaded with I2/TESH or Br2/TESH leading tothe formation of corresponding glycosyl halides, and b-isopropyl glycosidesreacted with Br2/BHQ resulting in the formation of a-glycosides. The anomerizationof glycosidic bond was considered to be catalyzed by in situ formation of hydrogenbromide from the mixing of Br2/BHQ.
- Xu, Lai,Luo, Chin-Hung,Chen, Chien-Sheng
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p. 315 - 321
(2020/07/13)
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- Compound, nitric oxide donor prodrug compound as well as preparation method and application of compound and nitric oxide donor prodrug compound
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The invention relates to the technical field of biological medicines, in particular to a compound, a nitric oxide donor prodrug compound as well as a preparation method and application of the compoundand the nitric oxide donor prodrug compound. The compound has a structure as shown in a formula I-1, is used for preparing the nitric oxide donor prodrug compound with a structure shown in a formulaI. The preparation method of the compound comprises the following steps: step c), condensing a compound as shown in a formula I-2 with pyrrolidinyl diazonium glycol sodium salt to prepare the compoundas shown in a formula I-1. The preparation method of the nitric oxide donor prodrug compound comprises the following steps: step d), deacetylating the compound of formula I-1 to prepare the compoundof formula I. The nitric oxide donor prodrug compound can controllably release nitric oxide under catalysis of endocellulase, and can controllably release nitric oxide under orthogonal catalysis of endocellulase Cel5A-h38 natural organisms. Therefore, a characteristic that nitric oxide can be controllably released as required is utilized for preparing a medicine capable of controllably releasing nitric oxide.
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Paragraph 0056; 0058
(2021/03/11)
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- Synthesis and antimicrobial studies of novel n-glycosyl hydrazino carbothioamide
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In view of applications of N-glycosylated compounds in medicinal chemistry and in many other ways, herein the synthesis of novel N-glycosyl hydrazino carbothioamides is reported. New N-glycosyl hydrazino carbothioamides were synthesized by the condensation of per-O-acetyl glycosyl isothiocyanate with different aromatic hydrazides. The newly synthesized compounds were characterized by using the IR, 1H NMR and mass spectral studies. Antimicrobial evaluation of the synthesized N-glycosyl hydrazino carbothioamide was also examined. Antimicrobial activities of the synthesized compound were evaluated against bacteria E. coli, P. aeruginosa, S. aureus, S. pyogenus and fungi C. albicans, A. niger and A. clavatus. All the N-glycosyl hydrazino carbothioamides exhibit promising antimicrobial activity.
- Nayak, Riddhi A.,Mangte, Anvita D.
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p. 127 - 131
(2021/01/06)
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- Folding control of a non-natural glycopeptide using saccharide-coded structural information for polypeptides
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We synthesized "glyco-arylopeptides", whose folding structure significantly changes depending on the kind of saccharide in their side chain. The saccharide moiety interacts with the main chain via hydrogen bonding, and the non-natural polypeptides form two well-defined architectures - (P)-31- and (M)-41-helices - depending on the length of the saccharide chains and even the configuration of a single stereo-genic center in the epimers.
- Fujii, Naoka,Haino, Takeharu,Ishido, Yuki,Kanbayashi, Naoya,Okamura, Taka-Aki,Onitsuka, Kiyotaka
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supporting information
p. 2767 - 2770
(2020/03/13)
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- Chemical synthesis of 5’-β-glycoconjugates of vitamin B6
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Various 5’-β-saccharides of pyridoxine, namely the mannoside, galactoside, arabinoside, maltoside, cellobioside and glucuronide, were synthesized chemically according to KOENIGS-KNORR conditions using α4,3-O-isopropylidene pyridoxine and the respective acetobromo glycosyl donors with AgOTf (3.0 eq.) and NIS (3.0 eq.) as promoters at 0 °C. Furthermore, 5’-β-[13C6]-labeled pyridoxine glucoside (PNG) was prepared starting from [13C6]-glucose and pyridoxine. Additionally, two strategies were examined for the synthesis of 5’-β-pyridoxal glucoside (PLG).
- Bachmann, Thomas,Schnurr, Christian,Zainer, Laura,Rychlik, Michael
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supporting information
(2020/02/15)
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- Potential anti-herpes and cytotoxic action of novel semisynthetic digitoxigenin-derivatives
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In recent years, new therapeutic possibilities were proposed for cardiac glycosides traditionally used to treat heart diseases, such as anticancer and antiviral activities. In this sense, this work aimed to synthesize the readily accessible 3β-azido-3-deoxydigitoxigenin (5) from digitoxigenin (1). Two new series of compounds were obtained from derivative (5): (i) O-glycosyl trizols through click chemistry with propargyl glycosides; and (ii) compounds substituted in the alpha carbonyl position with different residues linked via an amino-group. All obtained derivatives have their chemical structures confirmed, and their anti-herpes (against HSV-types 1 and 2 replication) and cytotoxic (against PC3, A549, HCT-8 and LNCaP cell lines) activities evaluated. Compounds 10 and 11 exhibited the most promising results against HSV-1 (KOS and 29-R strains) and HSV-2 (333 strain) replication with SI values > 1000. Both compounds were also the most cytotoxic for the human cancer cell lines tested with IC50 values similar to those of paclitaxel. They also presented reduced toxicity toward non-cancerous cell lines (MRC-5 and HGF cells). Promising compounds were tested in regard to their ability to inhibit Na+/K+-ATPase. The inhibition rate correlates suitably with the bioactivity demonstrated by those both compounds against the different human cancer cells tested as well as against HSV replication. Moreover, the results showed that specific chemical features of compound 10 and 11 influenced the bioactivities tested. In summary, it was possible to obtain novel digitoxigenin-derivatives with remarkable cytotoxic and anti-herpes activities as well as low toxicity and high selectivity. In this way, they could be considered potential molecules for the development of new drugs.
- Boff, Laurita,Munkert, Jennifer,Ottoni, Flaviano Melo,Zanchett Schneider, Naira Fernanda,Ramos, Gabriela Silva,Kreis, Wolfgang,Fernandes de Andrade, Saulo,Dias de Souza Filho, José,Braga, Fern?o Castro,Alves, Ricardo José,Maia de Pádua, Rodrigo,Oliveira Sim?es, Cláudia Maria
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p. 546 - 561
(2019/02/25)
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- Controlling the Kinetics of Self-Reproducing Micelles by Catalyst Compartmentalization in a Biphasic System
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Compartmentalization of reactions is ubiquitous in biochemistry. Self-reproducing lipids are widely studied as chemical models of compartmentalized biological systems. Here, we explore the effect of catalyst location on copper-catalyzed azide-alkyne cycloadditions which drive the self-reproduction of micelles from phase-separated components. Tuning the hydrophilicity of the copper-ligand complex, so that hydro-phobic or -philic catalysts are used in combination with hydro-philic and -phobic coupling partners, provides a wide range of reactivity patterns. Analysis of the kinetic data shows that reactions with a hydrophobic catalyst are faster than with a hydrophilic catalyst. Diffusion-ordered spectroscopy experiments suggest compartmentalization of the hydrophobic catalyst inside micelles while the hydrophilic catalyst remains in the bulk aqueous phase. The autocatalytic effects observed can be tuned by varying reactant structure and coupling a hydrophilic alkyne and hydrophobic azide results in a more pronounced autocatalytic effect. We propose and test a model that rationalizes the observations in terms of the phase behavior of the reaction components and catalysts.
- Post, Elias A. J.,Fletcher, Stephen P.
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p. 2741 - 2755
(2019/02/26)
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- Design, synthesis of oleanolic acid-saccharide conjugates using click chemistry methodology and study of their anti-influenza activity
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The development of entry inhibitors is an emerging approach to the inhibition of influenza virus. In our previous research, oleanolic acid (OA) was discovered as a mild influenza hemagglutinin (HA) inhibitor. Herein, as a further study, we report the preparation of a series of OA-saccharide conjugates via the CuAAC reaction, and the anti-influenza activity of these compounds was evaluated in vitro. Among them, compound 11b, an OA-glucose conjugate, showed a significantly increased anti-influenza activity with an IC50 of 5.47 μM, and no obvious cytotoxic effect on MDCK cells was observed at 100 μM. Hemagglutination inhibition assay and docking experiment indicated that 11b might interfere with influenza virus infection by acting on HA protein. Broad-spectrum anti-influenza experiments showed 11b to be robustly potent against 5 different strains, including influenza A and B viruses, with IC50 values at the low-micromole level. Overall, this finding further extends the utility of OA-saccharide conjugates in anti-influenza virus drug design.
- Su, Yangqing,Meng, Lingkuan,Sun, Jiaqi,Li, Weijia,Shao, Liang,Chen, Kexuan,Zhou, Demin,Yang, Fan,Yu, Fei
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- COMPOUNDS FOR TREATING AND PREVENTING EXTRACELLULAR HISTONE MEDIATED PATHOLOGIES
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The present invention relates to compounds with high chemical stability and methods for inhibiting the pathological activity of extracellular histones in a subject. In particular, the invention relates to compounds with high chemical stability, uses thereof and methods for inhibiting or ameliorating extracellular histone mediated ailments (such as, for example, sepsis, systemic immune response syndrome (SIRS) and ischemia reperfusion injury (IRI)). More particularly, the invention relates to methods and uses of a polyanionic sulfated cellobioside modified with a small uncharged glycosidically linked substituent at its reducing terminus, wherein the presence of the substituent results in a molecule with high chemical stability without affecting the ability of the molecule to be effective in the therapy of extracellular histone mediated ailments. For example, the present invention relates to methods and uses of β-O-methyl cellobioside sulfate (mCBS) or a pharmaceutically acceptable salt thereof (e.g., mCBS.Na), in the therapy of a range of extracellular histone mediated ailments in subjects.
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Paragraph 0280; 0282-0285
(2019/07/19)
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- New water soluble glycosides of 11-keto-β-boswellic acid: A paradigm
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Though several glycosides of various triterpenes are known, but surprisingly no boswellic acid glycosides are reported so far. With a view to make water soluble boswellic acids, prepared glycosides of 11-keto boswellic acid for the first time. Naturally occurring boswellic acids which are anti-inflammatory agents are lipophylic in nature and thus, become a limiting factor in terms of their bioavailability. Among boswellic acids, 11-keto-β-boswellic acid is found to exhibit superior biological activity and hence successfully prepared its glucosyl and maltosyl derivatives viz., 11-keto-β-boswellic acid-24-O-β-D-glucopyranoside (9) and 11-keto-β-boswellic acid-24-O-α-D-glucopyranosyl-(1?→?4)-β-D-glucopyranoside (15) which are water soluble. Both these compounds are soluble in water to the extent of 10% (w/w) which is very significant.
- Manjunath,Shenvi, Suvarna,Raja,Reddy, G. Chandrasekara
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p. 154 - 161
(2017/10/05)
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- Self-reproducing micelles coupled to a secondary catalyst
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We report a physical autocatalytic system where micelles self-reproduce via a copper-catalyzed azide-alkyne cycloaddition in a biphasic reaction mixture. The coupling of a secondary catalyst to an autocatalytic cycle opens up new opportunities to control and probe autocatalytic processes.
- Post, Elias A. J.,Bissette, Andrew J.,Fletcher, Stephen P.
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supporting information
p. 8777 - 8780
(2018/08/07)
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- Iridium catalysis: Reductive conversion of glucan to xylan
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By using iridium catalysed dehydrogenative decarbonylation, we converted a partly protected cellobioside into a fully protected xylobioside. We demonstrate good yields with two different aromatic ester protecting groups. The resulting xylobioside was directly used as glycosyl donor in further synthesis of a xylooctaose.
- Pedersen, Martin J?ger,Madsen, Robert,Clausen, Mads Hartvig
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supporting information
p. 952 - 955
(2018/02/07)
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- Preparation and functional analysis of gossypols having two carbohydrate appendages with enaminooxy linkages
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We developed new gossypol (Gos)-based glycoconjugates through dehydration condensation of native Gos and chemically modified glycosides having aminooxy groups. The resultant glycoconjugates (glycoGos) were resistant to hydrolysis, although they were light-sensitive and slowly decomposed even under indoor lighting. The glycoGos also exhibited improved water solubility compared with native Gos, but their saturated concentrations in water were still low (6.4–17 μM), due to their hydrophobic naphthyl rings. We also carried out WST-8 assays to assess the anticancer activity of the glycoGos on DLD-1 and HepG2 cells and found that the glycoGos having β-lactosides and having β-galactosides (specific ligands for asialoglycoprotein receptors) showed enhanced anticancer activity on HepG2 cells.
- Amano, Yoshitsugu,Nakamura, Masaki,Shiraishi, Shinya,Chigira, Naoto,Shiozawa, Nobuya,Hagio, Masahito,Yano, Tomohiro,Hasegawa, Teruaki
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- Evaluation of anti α-d-Glc: P -(1→4)-α-d-Glc p (GAGA4) IgM antibodies as a biomarker for multiple sclerosis
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The correct diagnosis of multiple sclerosis (MS) remains challenging due to the complex pathophysiological and clinical characteristics of the disease. Consequently, there has been immense interest in finding a non-invasive diagnostic test for MS. Recent studies found that serum anti-α-d-Glcp-(1→4)-α-d-Glcp (GAGA4) IgM antibodies were upregulated in MS patients, and this finding led to the development of a commercial diagnostic test (gMS Dx test), although the test has poor selectivity and has not been independently validated. Herein, we developed an enzyme-linked immunosorbent assay (ELISA) to evaluate the use and reliability of several anti-glucose IgM antibodies, including those against GAGA4, as diagnostic biomarkers for MS. In contrast to previous studies, our results show that serum anti-GAGA4 IgM antibody levels are not significantly higher in MS patients, which could potentially explain the poor selectivity of the commercial test.
- Braganza, Chriselle D.,Santoso, Kristiana T.,Dangerfield, Emma M.,La Flamme, Anne C.,Timmer, Mattie S. M.,Stocker, Bridget L.
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p. 28086 - 28093
(2018/08/16)
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- From 1,4-Disaccharide to 1,3-Glycosyl Carbasugar: Synthesis of a Bespoke Inhibitor of Family GH99 Endo-α-mannosidase
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Understanding the enzyme reaction mechanism can lead to the design of enzyme inhibitors. A Claisen rearrangement was used to allow conversion of an α-1,4-disaccharide into an α-1,3-linked glycosyl carbasugar to target the endo-α-mannosidase from the GH99 glycosidase family, which, unusually, is believed to act through a 1,2-anhydrosugar "epoxide" intermediate. Using NMR and X-ray crystallography, it is shown that glucosyl carbasugar α-aziridines can act as reasonably potent endo-α-mannosidase inhibitors, likely by virtue of their shape mimicry and the interactions of the aziridine nitrogen with the conserved catalytic acid/base of the enzyme active site.
- Lu, Dan,Zhu, Sha,Sobala, Lukasz F.,Bernardo-Seisdedos, Ganeko,Millet, Oscar,Zhang, Yongmin,Jiménez-Barbero, Jesus,Davies, Gideon J.,Sollogoub, Matthieu
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supporting information
p. 7488 - 7492
(2019/01/03)
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- Synthesis of new saccharide azacrown cryptands
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Abstract New cryptands including bis-azacrown and saccharidic moieties in their structure were prepared in several steps by applying Staudinger-aza-Wittig reaction (SAW). Syntheses have been started from cheap, easily available commercial compounds such as D-glucose, D-cellobiose and D-lactose subsequently transformed into their derivatives in fairly good yields (60-65%) and suitable to give desired final cryptands by direct SAW coupling reactions.
- Pintal, Michalina,Charbonniere-Dumarcay, Florence,Marsura, Alain,Porwański, Stanis?aw
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- Synthesis of 2-deoxy-2,2-difluoro-α-maltosyl fluoride and its X-ray structure in complex with Streptomyces coelicolor GlgEI-V279S
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Streptomyces coelicolor (Sco) GlgEI is a glycoside hydrolase involved in α-glucan biosynthesis and can be used as a model enzyme for structure-based inhibitor design targeting Mycobacterium tuberculosis (Mtb) GlgE. The latter is a genetically validated drug target for the development of anti-Tuberculosis (TB) treatments. Inhibition of Mtb GlgE results in a lethal buildup of the GlgE substrate maltose-1-phosphate (M1P). However, Mtb GlgE is difficult to crystallize and affords lower resolution X-ray structures. Sco GlgEI-V279S on the other hand crystallizes readily, produces high resolution X-ray data, and has active site topology identical to Mtb GlgE. We report the X-ray structure of Sco GlgEI-V279S in complex with 2-deoxy-2,2-difluoro-α-maltosyl fluoride (α-MTF, 5) at 2.3 ? resolution. α-MTF was designed as a non-hydrolysable mimic of M1P to probe the active site of GlgE1 prior to covalent bond formation without disruption of catalytic residues. The α-MTF complex revealed hydrogen bonding between Glu423 and the C1F which provides evidence that Glu423 functions as proton donor during catalysis. Further, hydrogen bonding between Arg392 and the axial C2 difluoromethylene moiety of α-MTF was observed suggesting that the C2 position tolerates substitution with hydrogen bond acceptors. The key step in the synthesis of α-MDF was transformation of peracetylated 2-fluoro-maltal 1 into peracetylated 2,2-difluoro-α-maltosyl fluoride 2 in a single step via the use of Selectfluor.
- Thanna, Sandeep,Lindenberger, Jared J.,Gaitonde, Vishwanath V.,Ronning, Donald R.,Sucheck, Steven J.
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supporting information
p. 7542 - 7550
(2015/07/15)
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- Synthesis of 2-deoxy-2,2-difluoro-α-maltosyl fluoride and its X-ray structure in complex with Streptomyces coelicolor GlgEI-V279S
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Streptomyces coelicolor (Sco) GlgEI is a glycoside hydrolase involved in α-glucan biosynthesis and can be used as a model enzyme for structure-based inhibitor design targeting Mycobacterium tuberculosis (Mtb) GlgE. The latter is a genetically validated drug target for the development of anti-Tuberculosis (TB) treatments. Inhibition of Mtb GlgE results in a lethal buildup of the GlgE substrate maltose-1-phosphate (M1P). However, Mtb GlgE is difficult to crystallize and affords lower resolution X-ray structures. Sco GlgEI-V279S on the other hand crystallizes readily, produces high resolution X-ray data, and has active site topology identical to Mtb GlgE. We report the X-ray structure of Sco GlgEI-V279S in complex with 2-deoxy-2,2-difluoro-α-maltosyl fluoride (α-MTF, 5) at 2.3 ? resolution. α-MTF was designed as a non-hydrolysable mimic of M1P to probe the active site of GlgE1 prior to covalent bond formation without disruption of catalytic residues. The α-MTF complex revealed hydrogen bonding between Glu423 and the C1F which provides evidence that Glu423 functions as proton donor during catalysis. Further, hydrogen bonding between Arg392 and the axial C2 difluoromethylene moiety of α-MTF was observed suggesting that the C2 position tolerates substitution with hydrogen bond acceptors. The key step in the synthesis of α-MDF was transformation of peracetylated 2-fluoro-maltal 1 into peracetylated 2,2-difluoro-α-maltosyl fluoride 2 in a single step via the use of Selectfluor.
- Thanna, Sandeep,Lindenberger, Jared J.,Gaitonde, Vishwanath V.,Ronning, Donald R.,Sucheck, Steven J.
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supporting information
p. 7542 - 7550
(2015/11/27)
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- Synthesis of uniformly deuterated n-dodecyl-β -d-maltoside (d39 -DDM) for solubilization of membrane proteins in TROSY NMR experiments
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This work reports the first synthesis of uniformly deuterated n-dodecyl-β -D-maltoside (d39-DDM). DDM is a mild non-ionic detergent often used in the extraction and purification of membrane proteins and for solubilizing them in experimental studies of their structure, dynamics and binding of ligands. We required d39-DDM for solubilizing large α-helical membrane proteins in samples for [15N-1H]TROSY (transverse relaxation-optimized spectroscopy) NMR experiments to achieve the highest sensitivity and best resolved spectra possible. Our synthesis of d39-DDM used d7-D-glucose and d25-n-dodecanol to introduce deuterium labelling into both the maltoside and dodecyl moieties, respectively. Two glucose molecules, one converted to a glycosyl acceptor with a free C4 hydroxyl group and one converted to a glycosyl donor substituted at C1 with a bromine in the α-configuration, were coupled together with an α(1 → 4) glycosidic bond to give maltose, which was then coupled with n-dodecanol by its substitution of a C1 bromine in the α-configuration to give DDM. 1H NMR spectra were used to confirm a high level of deuteration in the synthesized d39-DDM and to demonstrate its use in eliminating interfering signals from TROSY NMR spectra of a 52-kDa sugar transport protein solubilized in DDM.
- Hiruma-Shimizu, Kazumi,Kalverda, Arnout P.,Henderson, Peter J. F.,Homans, Steve W.,Patching, Simon G.
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p. 737 - 743
(2015/02/19)
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- Synthesis and reactivity of 4'-deoxypentenosyl disaccharides
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4-Deoxypentenosides (4-DPs) are versatile synthons for rare or higher-order pyranosides, and they provide an entry for structural diversification at the C5 position. Previous studies have shown that 4-DPs undergo stereocontrolled DMDO oxidation; subsequent epoxide ring-openings with various nucleophiles can proceed with both anti or syn selectivity. Here, we report the synthesis of α- and β-linked 4'-deoxypentenosyl (4'-DP) disaccharides, and we investigate their post-glycosylational C5' additions using the DMDO oxidation/ring-opening sequence. The α-linked 4'-DP disaccharides were synthesized by coupling thiophenyl 4-DP donors with glycosyl acceptors using BSP/Tf2O activation, whereas β-linked 4'-DP disaccharides were generated by the decarboxylative elimination of glucuronyl disaccharides under microwave conditions. Both α- and β-linked 4'-DP disaccharides could be epoxidized with high stereoselectivity using DMDO. In some cases, the α-epoxypentenosides could be successfully converted into terminal l-iduronic acids via the syn addition of 2-furylzinc bromide. These studies support a novel approach to oligosaccharide synthesis, in which the stereochemical configuration of the terminal 4'-DP unit is established at a post-glycosylative stage.
- Padungros, Panuwat,Fan, Ren-Hua,Casselman, Matthew D.,Cheng, Gang,Khatri, Hari R.,Wei, Alexander
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p. 4878 - 4891
(2014/06/23)
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- Synthesis of quercetin glycosides and their melanogenesis stimulatory activity in B16 melanoma cells
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4′-O-β-d-Glucopyranosyl-quercetin-3-O-β-d-glucopyranosyl- (1→4)-β-d-glucopyra-noside (3) was isolated from Helminthostachys zeylanica root extract as a melanogenesis acceleration compound and was synthesized using rutin as the starting material Related compounds were also synthesized to understand the structure-activity relationships in melanin biosynthesis Melanogenesis activities of the glycosides were determined by measuring intracellular melanin content in B16 melanoma cells Among the synthesized quercetin glycosides, quercetin-3-O-β-d-glucopyranoside (1), quercetin-3-O-β-d-glucopyranosyl-(1→4)-β-d-glucopyranoside (2), and 3 showed more potent intracellular melanogenesis acceleration activities than theophyline used as positive control in a dose-dependent manner with no cytotoxic effect
- Yamauchi, Kosei,Mitsunaga, Tohru,Batubara, Irmanida
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p. 937 - 944
(2014/02/14)
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- Photocatalytic synthesis of glycosyl bromides
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Sugar hemiacetals were smoothly transformed into the corresponding glycosyl bromides by treatment with carbon tetrabromide in N,N-dimethylformamide with tris(2,2′-bipyridyl)ruthenium(II) chloride as a catalyst under visible-light irradiation. Protecting groups commonly used in carbohydrate derivatives are unaffected by the mild conditions for bromination. Georg Thieme Verlag KG Stuttgart · New York.
- Yuan, Xiaolong,Cheng, Sen,Shi, Yanbin,Xue, Weihua
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p. 331 - 335
(2014/02/14)
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- Glycosynthase with broad substrate specificity-an efficient biocatalyst for the construction of oligosaccharide library
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A versatile glycosynthase (TnG-E338A) with strikingly broad substrate scope has been developed from Thermus nonproteolyticus β-glycosidase (TnG) by using site-directed mutagenesis. The practical utility of this biocatalyst has been demonstrated by the facile generation of a small library containing various oligosaccharides and a steroidal glycoside (total 25 compounds) in up to 100 % isolated yield. Moreover, an array of eight gluco-oligosaccharides has been readily synthesized by the enzyme in a one-pot, parallel reaction, which highlights its potential in the combinatorial construction of a carbohydrate library that will assist glycomic and glycotherapeutic research. Significantly, the enzyme provides a means by which glycosynthase technology may be extended to combinatorial chemistry.
- Wei, Jinhua,Lv, Xun,Lue, Yang,Yang, Gangzhu,Fu, Lifeng,Yang, Liu,Wang, Jianjun,Gao, Jianhui,Cheng, Shuihong,Duan, Qian,Jin, Cheng,Li, Xuebing
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supporting information
p. 2414 - 2419
(2013/05/23)
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- Appel-reagent-mediated transformation of glycosyl hemiacetal derivatives into thioglycosides and glycosyl thiols
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A series of glycosyl hemiacetal derivatives have been transformed into thioglycosides and glycosyl thiols in a one-pot two-step reaction sequence mediated by Appel reagent (carbon tetrabromide and triphenylphosphine). 1,2-trans-Thioglycosides and β-glycosyl thiol derivatives were stereoselectively formed by the reaction of the in situ generated glycosyl bromides with thiols and sodium carbonotrithioate. The reaction conditions are reasonably simple and yields were very good.
- Ghosh, Tamashree,Santra, Abhishek,Misra, Anup Kumar
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p. 974 - 982
(2013/07/19)
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- Synthesis of fluorinated maltose derivatives for monitoring protein interaction by 19F NMR
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A novel reporter system, which is applicable to the 19F NMR investigation of protein interactions, is presented. This approach uses 2-F-labeled maltose as a spy ligand to indirectly probe protein-ligand or protein-protein interactions of proteins fused or tagged to the maltose-binding protein (MBP). The key feature is the simultaneous NMR observation of both 19F NMR signals of gluco/ manno-type-2-F-maltose-isomers; one isomer (α-gluco-type) binds to MBP and senses the protein interaction, and the nonbinding isomers (β-gluco- and/or α/β-manno-type) are utilized as internal references. Moreover, this reporter system was used for relative affinity studies of fluorinated and nonfluorinated carbohydrates to the maltose-binding protein, which were found to be in perfect agreement with published X-ray data. The results of the NMR competition experiments together with the established correlation between 19F chemical shift data and molecular interaction patterns, suggest valuable applications for studies of protein-ligand interaction interfaces.
- Braitsch, Michaela,Kaehlig, Hanspeter,Kontaxis, Georg,Fischer, Michael,Kawada, Toshinari,Konrat, Robert,Schmid, Walther
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supporting information; experimental part
p. 448 - 455
(2012/06/30)
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- Synthetic studies of bi-fluorescence-labeled maltooligosaccharides as substrates for α-amylase on the basis of fluorescence resonance energy transfer (FRET)
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A series of bi-fluorescence-labeled maltooligosaccharides that lead to fluorescence resonance energy transfer (FRET) was systematically synthesized. Effective FRETs were observed with all of the synthesized probes. Digestion of probes having tetra-, quintet-, hexa- or hepta-saccharidic chain lengths with human saliva α-amylase resulted in disappearance of FRET when an excitation wavelength of at 290 nm was used followed by detection at ca. 520 nm due to emission from the dansyl moiety. However, continuous FRET was observed when probes having di- or trisaccharidic chain lengths were used as substrates. In addition to the substrate characteristics based on saccharidic chain length, the reaction rates of digestion for the substrates by amylase were different and also depended on their saccharidic chain length.
- Oka, Hiroyuki,Koyama, Tetsuo,Hatano, Ken,Matsuoka, Koji
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experimental part
p. 435 - 445
(2012/03/10)
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- Sweet chiral porphyrins as singlet oxygen sensitizers for asymmetric Type II photooxygenation
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Carbohydrate-decorated meso-tetraarylporphyrins P-G and P-C were synthesized via Lewis-acid catalyzed condensation of acetylated carbohydrate-substituted benzaldehydes and pyrrole. Their efficiency of singlet oxygen production was compared with the corresponding non-substituted porphyrin. The oxidation of the spin trap molecule TEMP (2,2,6,6-tetramethyl-4-piperidone) by singlet oxygen to TEMPO was measured by ESR spectroscopy, showing higher reaction rates for the sugar porphyrins. These results were corroborate by laser flash photolysis measurements that resulted in higher triplet lifetimes of glucosyl- and cellobiosyl porphyrins in comparison with tetrakis(4- hydroxyphenyl)porphyrin. Low ee was detected in the photooxygenation of ethyl tiglate. The Royal Society of Chemistry and Owner Societies.
- Griesbeck, Axel G.,Miranda, Miguel A.,Uhlig, Johannes
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scheme or table
p. 1431 - 1435
(2012/06/30)
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- Comparative study of microwave induced and conventional synthesis of acetylated sugar isothiocyanates and related thiocarbamides
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The synthesis of several acetylated sugar isothiocyanates have been carried out under microwave irradiation in excellent yields of products by using related bromides and lead thiocyanate in sodium dried xylene. Several acetylated sugar thiocarbamides have been synthesized by the interaction of respective acetylated sugar isothiocyanates with appropriate aryl amines under microwave irradiation. Copyright E-Journal of Chemistry 2004-2011.
- Yadgire, Atul V.,Korpe, Gajanan V.,Deshmukh, Shirish P.
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p. 1614 - 1619
(2012/05/05)
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- Dynamic glycovesicle systems for amplified QCM detection of carbohydrate-lectin multivalent biorecognition
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We describe multivalent biorecognition of adsorbed lectin layers by biomimetic sensing nanoplatforms based on dynamic glycovesicles in a continuous flow QCM setup. The Royal Society of Chemistry.
- Mahon, Eugene,Aastrup, Teodor,Barboiu, Mihail
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supporting information; experimental part
p. 2441 - 2443
(2010/08/05)
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- Preparation of aminoethyl glycosides for glycoconjugation
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The synthesis of a number of aminoethyl glycosides of cell-surface carbohydrates, which are important intermediates for glycoarray synthesis, is described. A set of protocols was developed which provide these intermediates, in a short number of steps, from commercially available starting materials.
- Sardzik, Robert,Noble, Gavin T.,Weissenborn, Martin J.,Martin, Andrew,Webb, Simon J.,Flitsch, Sabine L.
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supporting information; experimental part
p. 699 - 703
(2011/01/03)
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- Synthesis of benzaldehyde-functionalized glycans: A novel approach towards glyco-SAMs as a tool for surface plasmon resonance studies
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In recent years the interest in tools for investigating carbohydrateprotein (CPI) and carbohydrate-carbohydrate interactions (CCI) has increased significantly. For the investigation of CPI and CCI, several techniques employing different linking methods are available. Surface plasmon resonance (SPR) imaging is a most appropriate tool for analyzing the formation of self-assembled monolayers (SAM) of carbohydrate derivatives, which can mimic the glycocalyx. In contrast to the SPR imaging methods used previously to analyze CPI and CCI, the novel approach reported herein allows a facile and rapid synthesis of linker spacers and carbohydrate derivatives and enhances the binding event by controlling the amount and orientation of ligand. For immobilization on biorepulsive amino-functionalized SPR chips by reductive amination, diverse aldehyde-functionalized glycan structures (glucose, galactose, mannose, glucosamine, cellobiose, lactose, and lactosamine) have been synthesized in several facile steps that include olefin metathesis. Effective immobilization and the first binding studies are presented for the lectin concanavalin A.
- Kopitzki, Sebastian,Jensen, Knud J.,Thiem, Joachim
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supporting information; experimental part
p. 7017 - 7029
(2010/09/10)
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- Studies on the boronation of methyl-β-d-cellobioside-a cellulose model
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The conversion of phenylboronic acid (PBA) with methyl-β-d-cellobioside (Me-β-d-clb) and cellodextrins (DPw 12) was investigated to gain a basic understanding of the interactions of boric acid derivatives with oligo- and polyglucans. By means of MS and NMR experiments, it was possible to show a first stage formation of a six-membered ring at C-4 and C-6 of the non-reducing glucose occurs as in the case of monosaccharides. If the amount of reagent is increased the formation of seven-membered rings at the secondary OH moieties is observed. Even the existence of two of these large ring-systems in the direct neighborhood was found. Application of an excess of boronation reagent led to dimerization reactions of Me-β-d-clb via the primary reducing glucose residue as confirmed by DOSY NMR studies. Preliminary 13C NMR studies for the interaction of cellodextrins with PBA in DMSO solution confirmed a functionalization at the trans-1,2-diol moieties of these oligomers. The amount of reagent applied may either was shown to lead to soluble products or to insoluble cross-linked material.
- Meiland, Marcel,Heinze, Thomas,Guenther, Wolfgang,Liebert, Tim
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experimental part
p. 257 - 263
(2010/04/02)
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- Conjugation of 2-(1′-hexyloxyethyl)-2-devinylpyropheophorbide-a (HPPH) to carbohydrates changes its subcellular distribution and enhances photodynamic activity in vivo
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The carbohydrate moieties on conjugating with 3-(1′-hexyloxyethyl)-3- devinyl pyropeophorbide-α (HPPH) altered the uptake and intracellular localization from mitochondria to lysosomes. In vitro, HPPH-Gal 9 PDT showed increased PDT efficacy over HPPH-PDT as detectable by the oxidative cross-linking of nonphosphorylated STAT3 and cell killing in ABCG2-expressing RIF cells but not in ABCG2-negative Colon26 cells. This increased efficacy in RIF cells could at least partially be attributed to increased cellular accumulation of 9, suggesting a role of the ABCG2 transporter for which HPPH is a substrate. While such differences in the accumulation in HPPH derivatives by tumor tissue in vivo were not detectable, 9 still showed an elevated light dose-dependent activity compared to HPPH in mice bearing RIF as well as Colon26 tumors. Further optimization of the carbohydrate conjugates at variable treatment parameters in vivo is currently underway.
- Zheng, Xiang,Morgan, Janet,Pandey, Suresh K.,Chen, Yihui,Tracy, Erin,Baumann, Heinz,Missert, Joseph R.,Batt, Carrie,Jackson, Jennifer,Bellnier, David A.,Henderson, Barbara W.,Pandey, Ravindra K.
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experimental part
p. 4306 - 4318
(2010/03/04)
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- Tandem staudinger-aza-Wittig templated reaction: De novo synthesis of sugar-ureido cryptands
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A templated Staudinger-aza-Wittig tandem reaction selectively affords in one step a monocellobiosyl[bis(ureido)]di- azacrown cryptand and a bis(cellobiosyl)tetraureido[bis(di- azacrown)] cryptand. Formation of each type of cryptand was under control by Na
- Porwanski, Stanislaw,Marsura, Alain
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supporting information; experimental part
p. 2047 - 2050
(2009/09/06)
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- Synthesis of urea tethered glycosylated amino acids and glycopeptides mediated by DPPA employing Nα-Fmoc-Asp/Glu-5-oxazolidinones
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The utility of diphenyl phosphoryi azide (DPPA) as azido transfer reagent for the insertion of urea moiety between β/γ carboxyl group of N a-Fmoc-Asp/Glu-5-oxazolidinones and glycosyl amine has been demonstrated. Utility of this protocol for the synthesis of urea-linked neoglycopeptides has also been explored. The compounds are characterised by '1H NMR, l3C NMR and mass spectroscopy.
- Nagendra,Hemantha,Sureshbabu, Vommina V.
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scheme or table
p. 397 - 407
(2009/12/26)
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- NOVEL SULFATED OLIGOSACCHARIDE DERIVATIVES
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The invention relates to novel compounds that have utility as inhibitors of heparan sulfate-binding proteins; compositions comprising the compounds, and use of the compounds and compositions thereof for the antiangiogenic, antimetastatic, anti-inflammatory, antimicrobial, anticoagulant and/or antithrombotic treatment of a mammalian subject.
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Page/Page column 56
(2009/05/28)
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- Probing the lactose·GM3 carbohydrate - Carbohydrate interaction with glycodendrimers
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(Figure Presented) Multivalent glycoconjugates were prepared using generation-4 PAMAM dendrimers, and their interaction with Langmuir monolayers containing GM3 was investigated. Excessive carbohydrate valency adversely affects the carbohydrate-carbohydrate interaction. The GM3 monolayer selectively interacts with lactose-functionalized dendrimers in the presence of calcium ions.
- Seah, Nicole,Santacroce, Paul V.,Basu, Amit
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supporting information; experimental part
p. 559 - 562
(2009/07/30)
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- Facile synthesis of 2-0-lodoacetyl protected glycosyl iodides: Useful precursors of 1→2-linked 1,2-trans-glycosides
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(Chemical Equation Presented) The preparation and utilization of novel iodide glycosyl donors, 2-0-iodoacetyl-glycopyranosyl iodides, is described. The mechanism for the reaction of iodine with carbohydrate cyclic ketene acetal was investigated through lo
- Ko, Yoon-Joo,Shim, Seung-Bo,Shin, Jung-Hyu
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body text
p. 609 - 612
(2009/07/25)
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- A novel, simple cyclocondensation reaction towards glycosyl triazines
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Sugars bearing an isothiocyanate moiety at C-1 react with diazadienium iodide to afford glycosyl triazines that represent, through an easy cyclocondensation reaction step, a flexible entry to different nucleoside analogues. We herein demonstrate that this [4+2] cycloaddition reaction occurs with total regiocontrol and good yields. Subsequent transformation of the thiocarbonyl into a carbonyl, and nucleophilic substitution of the methylsulfanyl group by ammonia, yields the 5-azacytidine analogues. All compounds were fully characterised by IR, HRMS, and 13C and 1H NMR (COSY, HMBC and HMQC). Georg Thieme Verlag.
- Kikelj, Vincent,Julienne, Karine,Janvier, Pascal,Meslin, Jean-Claude,Deniaud, David
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scheme or table
p. 3453 - 3460
(2009/05/26)
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- Large-scale synthesis of per-O-acetylated saccharides and their sequential transformation to glycosyl bromides and thioglycosides
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This work describes a large-scale synthesis of per- O -acetylated mono- and disaccharides using a stoichiometric amount of acetic anhydride in the presence of LiClO 4 under solvent-free conditions. The peracetylated saccharides underwent subsequent anomeric bromination and thioglycosidation in one-pot to yield synthetically valuable building blocks. Copyright Taylor & Francis Group, LLC.
- Lin, Chan-Ching,Huang, Li-Cheng,Liang, Pi-Hui,Liu, Ching-Yang,Lin, Chun-Cheng
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p. 303 - 313
(2007/10/03)
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- Mild one-pot preparation of glycosyl bromides
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Mild one-pot protocols for the preparation of glycosyl bromides and alkyl bromides via in situ generation of HBr is reported here.
- Hunsen, Mo,Long, David A.,D'Ardenne, Christopher R.,Smith, Amanda L.
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p. 2670 - 2674
(2007/10/03)
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- The chemical synthesis of beta-(1-->4)-linked D-mannobiose and D-mannotriose.
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A D-cellobiose derivative was converted to D-mannobiose via simultaneous epimerization at C-2 and C-2'. Subsequent beta-D-glucosylation and epimerization at C-2" gave D-mannotriose.
- Twaddle, Gavin W,Yashunsky, Dmitry V,Nikolaev, Andrei V
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p. 623 - 628
(2007/10/03)
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- Synthetic long-chain alkyl maltosides and alkyl sucrose esters as enhancers of nasal insulin absorption
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A series of new glycosides with extended alkyl side-chains (C13-16) linked to maltose or sucrose were synthesized and tested for their efficacy in enhancing nasal insulin absorption in anesthetized rats. The new reagents were compared to previously tested alkylglycosides with shorter alkyl side chains (C8-12). Dose-response studies revealed that within the family of alkylmaltoside derivatives, (C8-16), maximal increases in insulin absorption took place when tetradecylmaltoside (C14) was added to the formulation. Pentadecylmaltoside (C15) and hexadecylmaltoside (C16) were less potent at increasing insulin absorption, although both reagents achieved maximal effects when used at higher concentrations. Within the family of alkanoylsucrose derivatives, tride-canoylsucrose (C13) and tetradecanoylsucrose (C14) were most potent at increasing insulin absorption. Cross-comparisons between alkylmaltoses and alkanoylsucroses showed that the alkyl chain length had a greater impact than the glycoside moiety in determining the potency of a potential insulin-absorption enhancing agent. When tetradecylmaltoside was applied to the nasal mucosa 15 min before insulin was applied, the enhanced insulin absorption was still observed.
- Pillion, Dennis J.,Ahsan, Fakhrul,Arnold, John J.,Balusubramanian, Balu M.,Piraner, Olga,Meezan, Elias
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p. 1456 - 1462
(2007/10/03)
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- Mild synthesis of disaccharidic 2,3-enopyranosyl cyanides and 2-C-2-deoxy pyranosyl cyanides with Hg(CN)2/HgBr2/TMSCN
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Lewis acid-catalyzed dimerization of mono- and disaccharidic per-O-acetylated glycals gave di- and tetrasaccharidic O-acetylated C-glycosides, respectively. 2,3-Enopyranosyl cyanides were obtained from per-O-acetylated glycals by a new, mild anomeric SN′-acetoxy displacement with Hg(CN)2/HgBr2/TMSCN. Per-O-acetylated 2-C-2-deoxy-pyranoses were converted into pyranosyl cyanides by the same reagent. An unprecedented acetic acid elimination from dimers with D-galacto- and L-fuco-configurations accompanied the SN-displacement under those conditions. A new set of 1H NMR coupling constants for 2,3-enopyranosyl systems was used for configurational assignment of complicated tetrasaccharide mimics.
- Franz, Andreas H.,Wei, YiQiu,Samoshin, Vyacheslav V.,Gross, Paul H.
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p. 7662 - 7669
(2007/10/03)
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