- Azidonitration of di-O-acetyl-L-fucal: X-Ray crystal structures of intermediate azidodeoxysugars and of the bacterial aminosugar N-acetyl-L-fucosamine
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The azidonitration of di-O-acetyl-L-fucal has previously been shown to be an efficient route to the bacterial aminosugar N-acetyl-L-fucosamine. Upon repeating this sequence, with updated versions of the glycal formation and amide installation steps, we have obtained X-ray crystal structures of several of the addition products, which are now reported along with the solid-state structure of N-acetyl-L-fucosamine itself. Copyright Taylor & Francis Group, LLC.
- Alhassan, Abdul-Basit,McCutcheon, David C.,Zeller, Matthias,Norris, Peter
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Read Online
- 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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- Alpha-L-fucosidase detection probe and preparation method and application thereof
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The invention discloses an alpha-L-fucosidase detection probe. The structural general formula of the probe is shown in the specification, wherein in the formula I, R1 is an acetyl-protected monosaccharidyl or monosaccharidyl group; and R2 is a pyranonitrile group or a benzopyran nitrile group. The alpha-L-fucosidase detection probe prepared by the invention improves the detection sensitivity, can detect serum AFU with high selectivity, and can be used for kits or drugs for positioning and detecting cancer cells.
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- Excited-State Palladium-Catalyzed 1,2-Spin-Center Shift Enables Selective C-2 Reduction, Deuteration, and Iodination of Carbohydrates
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Excited-state catalysis, a process that involves one or more excited catalytic species, has emerged as a powerful tool in organic synthesis because it allows access to the excited-state reaction landscape for the discovery of novel chemical reactivity. Herein, we report the first excited-state palladium-catalyzed 1,2-spin-center shift reaction that enables site-selective functionalization of carbohydrates. The strategy features mild reaction conditions with high levels of regio- and stereoselectivity that tolerate a wide range of functional groups and complex molecular architectures. Mechanistic studies suggest a radical mechanism involving the formation of hybrid palladium species that undergoes a 1,2-spin-center shift followed by the reduction, deuteration, and iodination to afford functionalized 2-deoxy sugars. The new reactivity will provide a general approach for the rapid generation of natural and unnatural carbohydrates.
- Zhao, Gaoyuan,Yao, Wang,Mauro, Jaclyn N.,Ngai, Ming-Yu
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supporting information
p. 1728 - 1734
(2021/02/06)
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- Nickel-Catalyzed Radical Migratory Coupling Enables C-2 Arylation of Carbohydrates
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Nickel catalysis offers exciting opportunities to address unmet challenges in organic synthesis. Herein we report the first nickel-catalyzed radical migratory cross-coupling reaction for the direct preparation of 2-Aryl-2-deoxyglycosides from readily available 1-bromosugars and arylboronic acids. The reaction features a broad substrate scope and tolerates a wide range of functional groups and complex molecular architectures. Preliminary experimental and computational studies suggest a concerted 1,2-Acyloxy rearrangement via a cyclic five-membered-ring transition state followed by nickel-catalyzed carbon-carbon bond formation. The novel reactivity provides an efficient route to valuable C-2-Arylated carbohydrate mimics and building blocks, allows for new strategic bond disconnections, and expands the reactivity profile of nickel catalysis.
- Zhao, Gaoyuan,Yao, Wang,Kevlishvili, Ilia,Mauro, Jaclyn N.,Liu, Peng,Ngai, Ming-Yu
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supporting information
p. 8590 - 8596
(2021/06/28)
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- Neuroprotective activity of different monosaccharide-modified gastrodin analogs
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Gastrodin is a very important and well-known bioactive glycoside compound in Chinese medicine. It is also known as a drug with neuroprotective function. Here, a practical diversified synthesis of a series of gastrodin analogs was reported, which involved four-step procedures consisting of bromination, oxidation, etherification, and reduction. Various gastrodin analogs were obtained in good yields. The compound 4c in this study has a good neuroprotective function: it can significantly downregulate tumor necrosis factor-α and inducible nitric oxide synthase protein levels. The results of this study can provide a research basis for the development of neuroprotective drugs.
- Xu, Kun-Lun,Yu, Lan
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p. 1263 - 1269
(2020/01/21)
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- Total Syntheses of Resin Glycosides Murucoidins IV and v
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Murucoidins IV and V, two bioactive resin glycosides with complex yet similar structures isolated from the morning glory family, were synthesized in a convergent manner. All of the glycosylations in these syntheses including the key [3 + 2] coupling were
- Fang, Jing,Zeng, Jing,Sun, Jiuchang,Zhang, Shuxin,Xiao, Xiong,Lu, Zimin,Meng, Lingkui,Wan, Qian
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supporting information
p. 6213 - 6216
(2019/09/04)
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- Lewis acid promoted anomerisation of alkyl O- and S-xylo-, arabino- and fucopyranosides
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Pentopyranoside and 6-deoxyhexopyranosides, such as those from D-xylose, L-arabinose and L-fucose are components of natural products, oligosaccharides or polysaccharides. Lewis acid promoted anomerisation of some of their alkyl O- and S-glycopyranosides i
- Doyle, Lisa M.,Meany, Fiach B.,Murphy, Paul V.
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- Synthesis and cytotoxicity evaluation of glycosidic derivatives of lawsone against breast cancer cell lines
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Breast cancer is the most incident and mortal cancer type in women, with an estimated 2 million new cases expected by 2020 worldwide, with 600,000 deaths. As not all breast cancer types respond to the anti-hormonal therapy, the development of new antineoplastic drugs is necessary. Lawsone (2-hydroxy-1,4-naphtoquinone) is a natural bioactive naphtoquinone displaying a range of activities, with dozens of derivatives described in the literature, including some glycosides possessing antitumor activity. Here, a series of glycosides of lawsone are reported for the first time and all compounds displayed good activity against the SKBR-3 cell line, with IC50 below 10 μM. The most promising derivative was the glycosyl triazole derived from peracetylated D-glucose (11), which showed better cytotoxicity against SKBR-3 (IC50 = 0.78 μM), being the most selective toward this tumoral cell (SI > 20). All compounds described in this work were more active than lawsone, indicating the importance of the carbohydrate and glycosyl triazole moiety for activity.
- Alves, Ricardo J.,Gomes, Eliza R.,Oliveira, M?nica C.,Ottoni, Flaviano M.,Pádua, Rodrigo M.,Silva, Izabella T.
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- OLIGONUCLEOTIDE DERIVATIVE, OLIGONUCLEOTIDE CONSTRUCT USING THE SAME, AND METHODS FOR PRODUCING THEM
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The oligonucleotide derivative of the present invention is represented by Formula (1). This derivative is considered to be introduced into cells by binding of its amino sugar chain moiety to a ligand on cell surfaces, and have selective drug delivery function. The oligonucleotide derivative can be easily synthesized and introduced into cells without using a lipofection reagent. wherein—A and B are independently modified or unmodified oligonucleotides whose total chain length is 3 or more, and A and B do not contain hydroxyl groups at 3′ and 5′ ends of the oligonucleotide; S represents a sugar substituent, a peptide chain, or a tocopherol-binding group; and an alkyl group may be bound instead of hydrogen bound to a benzene ring.
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Paragraph 0160
(2018/04/19)
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- Designer α1,6-Fucosidase Mutants Enable Direct Core Fucosylation of Intact N-Glycopeptides and N-Glycoproteins
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Core fucosylation of N-glycoproteins plays a crucial role in modulating the biological functions of glycoproteins. Yet, the synthesis of structurally well-defined, core-fucosylated glycoproteins remains a challenging task due to the complexity in multistep chemical synthesis or the inability of the biosynthetic α1,6-fucosyltransferase (FUT8) to directly fucosylate full-size mature N-glycans in a chemoenzymatic approach. We report in this paper the design and generation of potential α1,6-fucosynthase and fucoligase for direct core fucosylation of intact N-glycoproteins. We found that mutation at the nucleophilic residue (D200) did not provide a typical glycosynthase from this bacterial enzyme, but several mutants with mutation at the general acid/base residue E274 of the Lactobacillus casei α1,6-fucosidase, including E274A, E274S, and E274G, acted as efficient glycoligases that could fucosylate a wide variety of complex N-glycopeptides and intact glycoproteins by using α-fucosyl fluoride as a simple donor substrate. Studies on the substrate specificity revealed that the α1,6-fucosidase mutants could introduce an α1,6-fucose moiety specifically at the Asn-linked GlcNAc moiety not only to GlcNAc-peptide but also to high-mannose and complex-type N-glycans in the context of N-glycopeptides, N-glycoproteins, and intact antibodies. This discovery opens a new avenue to a wide variety of homogeneous, core-fucosylated N-glycopeptides and N-glycoproteins that are hitherto difficult to obtain for structural and functional studies.
- Li, Chao,Zhu, Shilei,Ma, Christopher,Wang, Lai-Xi
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p. 15074 - 15087
(2017/11/03)
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- Stereoselective Epimerizations of Glycosyl Thiols
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Glycosyl thiols are widely used in stereoselective S-glycoside synthesis. Their epimerization from 1,2-trans to 1,2-cis thiols (e.g., equatorial to axial epimerization in thioglucopyranose) was attained using TiCl4, while SnCl4 promoted their axial-to-equatorial epimerization. The method included application for stereoselective β-d-manno- and β-l-rhamnopyranosyl thiol formation. Complex formation explains the equatorial preference when using SnCl4, whereas TiCl4 can shift the equilibrium toward the 1,2-cis thiol via 1,3-oxathiolane formation.
- Doyle, Lisa M.,O'Sullivan, Shane,Di Salvo, Claudia,McKinney, Michelle,McArdle, Patrick,Murphy, Paul V.
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p. 5802 - 5805
(2017/11/10)
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- O-Alkylated heavy atom carbohydrate probes for protein X-ray crystallography: Studies towards the synthesis of methyl 2-O-methyl-L-selenofucopyranoside
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Selenoglycosides are used as reactive glycosyl donors in the syntheses of oligosaccharides. In addition, such heavy atom analogs of natural glycosides are useful tools for structure determination of their lectin receptors using X-ray crystallography. Some
- Sommer, Roman,Hauck, Dirk,Varrot, Annabelle,Imberty, Anne,Künzler, Markus,Titz, Alexander
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p. 2828 - 2833
(2017/01/09)
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- Organoboron-Promoted Regioselective Glycosylations in the Synthesis of a Saponin-Derived Pentasaccharide from Spergularia ramosa
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Organoboron-mediated regioselective glycosylations were employed as key steps in the total synthesis of a branched pentasaccharide from a saponin natural product. The ability to use organoboron activation to differentiate OH groups in an unprotected glycosyl acceptor, followed by substrate-controlled reactions of the obtained disaccharide, enabled a streamlining of the synthesis relative to a protective group-based approach. This study revealed a matching/mismatching effect of the relative configuration of donor and acceptor on the efficiency of a regioselective glycosylation reaction, a problem that was solved through the development of a novel boronic acid-amine copromoter system for glycosyl acceptor activation.
- Mancini, Ross S.,McClary, Corey A.,Anthonipillai, Stefi,Taylor, Mark S.
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p. 8501 - 8510
(2015/09/15)
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- METHODS AND COMPOSITIONS FOR MAKING ANTIBODIES AND ANTIBODY DERIVATIVES WITH REDUCED CORE FUCOSYLATION
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The invention provides methods and compositions for preparing antibodies and antibody derivatives with reduced core fucosylation.
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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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- STEROID COMPOUND
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A steroid compound of the Formula (1): [wherein R1 represents a group selected from the group consisting of H, CH3, C2H5, C3H7 and CH (CH3)2, R2 represents a group selected from NH2, NHAc and OCOR1, R3 represents a group selected from the group consisting of CH3, COOCH3 and CH2OCOR1.]
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Page/Page column 5
(2012/03/26)
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- STEROID COMPOUND
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A steroid compound of the Formula (1): [wherein R1 represents a group selected from the group consisting of H, CH3, C2H5, C3H7 and CH (CH3)2, R2 represents a group selected from NH2, NHAc and OCOR1, R3 represents a group selected from the group consisting of CH3, COOCH3 and CH2OCOR1.]
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Page/Page column 8
(2012/02/04)
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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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- Magnetic glyco-nanoparticles: A tool to detect, differentiate, and unlock the glyco-codes of cancer via magnetic resonance imaging
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Within cancer, there is a large wealth of diversity, complexity, and information that nature has engineered rendering it challenging to identify reliable detection methods. Therefore, the development of simple and effective techniques to delineate the fin
- Ei-Boubbou, Kheireddine,Zhu, David C.,Vasileiou, Chrysoula,Borhan, Babak,Prospen, Davide,Wei,Huang, Xuefei
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supporting information; experimental part
p. 4490 - 4499
(2010/06/13)
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- Total synthesis of ipomoeassin F
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The first total synthesis of ipomoeassin F was carried out using a convergent approach that relied upon the use of Schmidt glycosidation technology for the coupling of two suitably protected monosaccharide fragments. After two steps, ring-closing metathes
- Postema, Maarten H. D.,Tendyke, Karen,Cutter, James,Kuznetsov, Galina,Xu, Qunli
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supporting information; experimental part
p. 1417 - 1420
(2009/10/02)
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- Total synthesis and biological evaluation of the cytotoxic resin glycosides ipomoeassin A-F and analogues
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A multitasking C-silylation strategy using the readily available compound 26 as a surrogate for cinnamic acid represents the key design element of a total synthesis of all known members of the ipomoeassin family of resin glyosides. This protecting group maneuver allows the unsaturated acids decorating the glucose subunit of the targets to be attached at an early phase of the synthesis, prevents their participation in the ruthenium-catalyzed ring-closing metathesis (RCM) used to form the macrocyclic ring, and protects them against reduc tion during the hydrogenation of the resulting cycloalkene over Wilkinson's catalyst. As the C-silyl group can be concomitantly removed with the O-TBS substituent using tris(dimethylamino)sulfonium difluorotrimethylsilicate (TASF) in acetonitrile, no separate protecting group manipulations were necessary in the final stages, thus contributing to a favorable overall "economy of steps". In addition to the naturally occurring ipomoeassins, a small set of synthetic analogues has also been prepared by "diverted total synthesis". The cytotoxicity of these compounds was assayed with two different cancer cell lines. The recorded data confirm previous findings that the acylation- and oxygenation pattern of these amphiphilic glycoconjugates is highly correlated with their biological activity profile. Ipomoeassin F turned out to be the most promising member of the series, showing IC50 values in the low nanomolar range.
- Nagano, Takashi,Pospisil, Jiri,Chollet, Guillaume,Schulthoff, Saskia,Hickmann, Volker,Moulin, Emilie,Herrmann, Jennifer,Mueller, Rolf,Fuerstner, Alois
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supporting information; experimental part
p. 9697 - 9706
(2010/04/29)
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- A facile preparation of trehalose analogues: 1,1-thiodisaccharides
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The synthesis of 1,1-thiodisaccharide trehalose analogues in good to excellent yields by a Lewis acid (BF3·Et2O)-catalysed coupling of sugar per-O-acetate with thiosugar is described. The reactivity of different sugar per-O-acetates and thiosugars is explored.
- Morais, Goreti Ribeiro,Humphrey, Andrew J.,Falconer, Robert A.
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experimental part
p. 1039 - 1045
(2009/09/05)
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- Synthesis of per-acetyl D-fucopyranosyl bromide and its use in preparation of diphyllin D-fucopyranosyl glycoside
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The per-O-acetyl-d-fucosyl bromide (9) was expediently prepared for C-6 deoxygenation of d-galactose in six steps in 32.5% yield. Employing phase transfer catalysis glycosylation (PTC), d-fucopyranosyl diphyllin (4), the analog of natural diphyllin glycoside, was synthesized by using 9 as the glycosyl donor in 67.1% in two steps. The product was identified by 1H NMR, 13C NMR, and HRMS. Its abilities to inhibit the growth of cancer cells in vitro also are discussed. Copyright Taylor & Francis Group, LLC.
- Yu, Zhao,Ya-Peng, Lu,Li, Zhu
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p. 113 - 119
(2008/09/21)
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- Total syntheses of ipomoeassin B and E
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A concise, flexible, and efficient total synthesis of the cytotoxic resin glycosides ipomoeassin B (1) and ipomoeassin E (2) is reported which features the advantages of a novel protecting group strategy employing (Z)-3-dimethyl(phenyl)silyl-2-propenoic acid as cinnamic acid surrogate. The use of this readily available compound allowed the macrocycle of the glycolipids to be formed by ring closing olefin metathesis (RCM) with the aid of the second generation Grubbs carbene complex 12. The resulting E/Z mixture could be selectively hydrogenated using Wilkinson's catalyst [RhCl(PPh3)3] without affecting the unsaturated esters in the periphery of the compound, before the C-silyl group was cleaved off with TASF [tris(dimethylamino)sulfonium difluorotrimethylsilicate] under notably mild conditions to release the required cinnamate moiety. Other key steps of the synthesis route comprise the formation of the disaccharide linkage by the trichloroacetimidate method, the formation of the chiral acid segment 19 via a VO(acac)2-catalyzed, tert-BuOOH-induced oxidative rearrangement of the optically pure furyl alcohol (-)-15 (Achmatowicz-type reaction), and a reductive cleavage of the 4,6-O-p-methoxybenzylidene acetal in 5 with NaBH3CN and Me3SiCl (TMSCl), the regiochemical course of which was found to be opposite to that previously reported in the literature for sterically less encumbered substrates. Copyright
- Fuerstner, Alois,Nagano, Takashi
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p. 1906 - 1907
(2007/10/03)
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- Synthesis of postulated molecular probes: Stereoselective free-radical-mediated C-glycosylation in tandem with hydrogen transfer
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Reported herein is a strategy employing an addition reaction in tandem with a hydrogen-transfer reaction for the elaboration of C-glycoside-based sialyl Lewis X (sLeX) analogues. Significant stereocontrol was noted when alkyl radicals were reacted with a series of alkoxytaconates. Transition states were proposed to explain the obtained selectivity. Further reaction between an anomeric-centered fucosyl-derived radical and a galactosylated hydroxytaconate provided easy access to C,O-diglycosides as mimics of sLeX. In this case, two 1,3-distant stereocenters were created with high diastereoselectivity using free radical intermediates in a tandem process.
- Guindon, Yvan,Bencheqroun, Mohammed,Bouzide, Abderrahim
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p. 554 - 558
(2007/10/03)
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- A facile synthesis of armed and disarmed colitose thioglycosides
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Ethyl 2,4-di-O-acetyl-3,6-dideoxy-1-thio-β-L-xylohexopyranoside (10) and ethyl 2,4-di-O-benzyl-3,6-dideoxy-1-thio-β-L-xyl0-hexopyranoside (12) were synthesized in 60% and 55% overall yield, respectively. Starting from α-L-fucose, sequential peracetylation
- Ruttens, Bart,Kovac, Pavol
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p. 2505 - 2508
(2007/10/03)
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- Synthesis of gold glyconanoparticles: Possible probes for the exploration of carbohydrate-mediated self-recognition of marine sponge cells
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The first step in marine sponge cell recognition and adhesion operates via a calcium-dependent proteoglycan-proteoglycan interaction. For the marine sponge Microciona prolifera, one of the carbohydrate epitopes involved in the proteoglycan self-recognition is a sulfated disaccharide [GlcpNAc3S(β1-3) Fucp]. Earlier surface plasmon resonance studies have demonstrated that the proteoglycan self-recognition can be mimicked with synthetic β-D-GlcpNAc-(1→3)-α-L-Fucp-(1→O), when multivalently presented by conjugation with bovine serum albumin. Here, the straightforward synthesis of water-soluble gold glyconanoparticles coated with the glycosides β-D-GlcpNAc3S-(1→3)-α-L-Fucp-(1→O)(CH2) 3S(CH2)6SH, β-D-GlcpNAc3S-(1→3)- β-L-Fucp-(1→O)(CH2)3S(CH2) 6SH, β-D-GlcpNAc3S-(1→O)(CH2) 3S-(CH2)6SH, α-L-Fucp-(1→O)(CH 2)3S(CH2)6SH, β-D-Glcp-NAc3S- (1→3)-α-L-Galp-(1→O)(CH2)3S(CH 2)6SH, β-D-Glcp-NAc-(1→3)-α-L-Fucp- (1→O)(CH2)3S(CH2)6SH, and β-D-Glcp3S-(1→3)-α-L-Fucp-(1→O)(CH2) 3S(CH2)6SH is presented. Such supramolecular structures are excellent probes for studying carbohydrate-carbohydrate interactions by transmission electron microscopy, thereby generating information on the molecular level about the role of different functionalities in the self-recognition process. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Carvalho De Souza, Adriana,Halkes, Koen M.,Meeldijk, Johannes D.,Verkleij, Arie J.,Vliegenthart, Johannes F. G.,Kamerling, Johannis P.
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p. 4323 - 4339
(2007/10/03)
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- Glyco-SAMs as glycocalyx mimetics: Synthesis of L-fucose- and D-mannose-terminated building blocks
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In the course of a project on the supramolecular functions of the glycocalyx present on eukaryotic cell surfaces, it has been our goal to prepare spacer glycosides and cluster glycosides that are suitable for the formation of self-assembled monolayers (SAMs) on gold. We have selected amino-functionalized D-mannose and L-fucose derivatives for peptide coupling to thio-functionalised alkane and alkane-oligoethylene glycol spacers such as 12 and 15. Thus, a variety of thiospacered glycosides (16-19) and cluster glycosides (23, 24, 26, 28, and 29) were synthesized, which can be assembled on gold wafers to serve as glycocalyx mimetics. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Kleinert, Mike,Roeckendorf, Niels,Lindhorst, Thisbe K.
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p. 3931 - 3940
(2007/10/03)
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- Synthesis of Lewis X trisaccharide analogues in which glucose and rhamnose replace N-acetylglucosamine and fucose, respectively
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Two analogues of the Lex trisaccharide, α-L-Fucp-(1→3)-[β-D-Galp-(1→4)]-D-Glcp were synthesized as allyl glycosides. In these derivatives either only the N-acetylglucosamine is replaced by glucose or both the N-acetylglucosamine and the fucosyl residue are replaced by glucose and rhamnose, respectively. Our synthetic scheme used armed β-thiophenyl fuco- and rhamnoside glycosyl donors that were prepared anomerically pure from the corresponding α-glycosyl bromides. The protecting groups were chosen to allow access to the fully deprotected trisaccharides without reduction of the allyl glycosidic group. These analogues will be used as soluble antigens in binding experiments with anti-Lex antibodies and can also be conjugated to a carrier protein and used as immunogens. In the course of this synthetic work, we also describe the use of reversed-phase HPLC to purify key protected trisaccharide intermediates prior to their deprotection.
- Asnani, Ari,Auzanneau, France-Isabelle
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p. 1045 - 1054
(2007/10/03)
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- Phenylmethyl 2,3,4-tri-O-acetyl-β-d-fucopyranoside
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The synthesis and X-ray analysis of the title compound is described. The peracetylated benzyl fucopyranoside derivative was prepared by following the classical Koenigs-Knorr methodology. The X-ray diffraction analysis showed a monoclinic system, with a =
- Brito-Arias, Marco,Garcia-Baez, Efren V.,Duran-Paramo, Enrique,Rojas-Lima, Susana
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p. 237 - 241
(2007/10/03)
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- A comparative analysis of mono- and disaccharide benzyl fucopyranosides
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The synthesis and x-ray analysis was carried out to compare mono- and disaccharide benzyl fucopyranosides. The molecular structure, hydrogen bonds, intermolecular interactions and crystal structure were described. The different substituents were found to
- Brito-Arias, Marco,Duran-Paramo, Enrique,Mata, Ignasi,Molins, Elies
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p. o537-o539
(2007/10/03)
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- Oligosaccharide synthesis with glycosyl phosphate and dithiophosphate triesters as glycosylating agents
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Described is an efficient one-pot synthesis of α- and β-glycosyl phosphate and dithiophosphate triesters from glycals via 1,2-anhydrosugars. Glycosyl phosphates function as versatile glycosylating agents for the synthesis of β-glucosidic, β-galactosidic,
- Plante,Palmacci,Andrade,Seeberger
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p. 9545 - 9554
(2007/10/03)
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- Stereoselective synthesis of α-L-Fucp-(1,2)- and -(1,3)-β-D-Galp(1)-4-methylumbelliferone using glycosyl donor substituted by propane-1,3-diyl phosphate as leaving group
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Stereoselective synthesis of α-L-Fucp-(1,2)- and -(1,3)-β-D-Galp(1)-4-methyllumbelliferone was accomplished using glycosyl donor substituted by propane-1,3-diyl phosphate as leaving group. The α-stereochemistry for the anomeric centre was assigned on the basis of the observed 13C-H coupling constant of 165.4 Hz for the bond. The results suggested that the bond-forming reaction intermediate was formed through participation of the second carbon acetoxy function or by an SN2-like process.
- Vankayalapati, Hariprasad,Singh, Gurdial
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p. 2187 - 2193
(2007/10/03)
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- Efficient total syntheses of resin glycosides and analogues by ring-closing olefin metathesis
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A highly efficient entry into the resin glycoside family of natural products is outlined which takes advantage of the inherently modular character of ring-closing metathesis (RCM) for the formation of their macrolactone substructures. Starting from only t
- Fuerstner, Alois,Mueller, Thomas
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p. 7814 - 7821
(2007/10/03)
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- Synthesis of cardenolide glycosides and putative biosynthetic precursors of cardenolide glycosides
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A rapid and efficient procedure for glycosylation of steroids was established using a modified Koenigs-Knorr procedure. Peracetylated β- glycosides were synthesized by reaction of cardenolides, various pregnanes and 23-nor-5,20(22)E-choldienic acid at room temperature with the peracetylated 1-bromo derivatives of D-glucose, D-galactose, D-fucose and cellobiose. Subsequent deprotection was performed by alkaline hydrolysis with sodium methoxide. Structures of the respective glycosides were established by NMR techniques. The complete protocol was shown to be non-destructive at all stages to the sugar moiety and the steroidal nucleus. The γ-unsaturated lactone ring of the cardenolides was shown to remain intact and no formation of C-14 unsaturated compounds was observed.
- Luta, Melitta,Hensel, Andreas,Kreis, Wolfgang
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- Synthesis and activity of dipeptides, linked to targeting ligands, as specific NK cell enhancers
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Water soluble analogues of the lipophilic immunostimulant, octadecyl D- alanyl-L-glutamine, BCH-527, were synthesized and evaluated for the ability to stimulate natural killer (NK) cells. One of these compounds in which the octadecyl chain of BCH-527 was
- Abbott, Shaun D.,Gagnon, Lyne,Lagraoui, Mouna,Kadhim, Salam,Attardo, Giorgio,Zacharie, Boulos,Penney, Christopher L.
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p. 1909 - 1926
(2007/10/03)
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- Convenient chemoenzymatic synthesis of β-purine-diphosphate sugars (GDP-fucose-analogues)
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A series of peracetylated β-sugar-1-phosphates with L-fuco configuration are efficiently prepared chemically and coupled in high yields to purine monophosphate bases via imidazolide activation. The resulting purine diphosphate sugars are deacetylated comp
- Baisch, Gabi,Oehrlein, Reinhold
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p. 383 - 391
(2007/10/03)
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- SYNTHESIS OF FULLY AND PARTIALLY PROTECTED ALKYL 1-THIO-β-L-FUCOPYRANOSIDES
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Fully acetylated (1d) and a mixture of partially acetylated (1a, 1b, 1c) ethyl 1-thio-β-L-fucopyranosides have been prepared in high yields from peracetylated fucopyranosyl chloride (1e) with sodium ethanethiolate/ethanethiol in 1,2-dimethoxyethane.The sa
- Dekany, Gyula,Ward, Peter,Toth, Istvan
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p. 227 - 236
(2007/10/02)
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- Synthesis of uridine 5′(α-D-fucopyranosyl diphosphate) and (digitoxigenin-3β-yl)-β-D-fucopyranoside and enzymatic β-D-fucosylation of cardenolide aglycones in Digitalis lanata
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The phosphorylation of 2,3,4-tri-Oacetyl-α-D-fucopyranose with o-phenylene phosphochloridate yielded α-D-fucopyranosyl phosphate which was used for condensation with undine 5′-monophosphomorpholidate to give uridine 5′-(α-D-fucopyranosyl diphosphate) (UDP-α-D-fucose). A crude enzyme preparation from young leaves of Digitalis lanata EHRH has been shown to catalyze the transfer of D-fucose from synthetic UDP-α-D-fucose to cardenolide aglycones, such as digitoxigenin. The reaction product was identified and characterized by chemical synthesis, HPLC, and spectral methods as the 3 β-O-β-D-fucopyranoside of digitoxigenin (digiproside). Copyright
- Faust,Theurer,Eger,Kreis
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p. 140 - 149
(2007/10/02)
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- SYNTHESIS AND POLYCONDENSATION OF GALACTO-CONFIGURATED MONOMERS VIA THE TRITYL-CYANO-ETHYLIDENE-PROCEDURE
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4-O-Acetyl-1,2--3-O-trityl-α-D-fucopyranose (13) and methyl 4-O-acetyl-1,2-O--3-O-trityl-α-D-galactopyranuronate (14) were synthesised.Trityl-cyanoethylidene condensation of the monomer 14 gave protected β-D-GalpA-(1->3)-D-GalpA-oligosaccharide derivatives with high stereoselectivity and a degree of polymerisation (d.p.) of eight.In the case of the D-fucose monomer 13, the yield of oligomers is surprisingly low and the d.p. does not exceed seven.This result is in contrast to the d.p. 20 - 60 obtained with other 6-deoxy-sugars, as previously described by Kochetkov and coworkers.
- Vogel, Christian,Bergemann, Claudia,Boye, Hanna,Ott, A. Ya.,Betaneli, V. I.,Kochetkov, N. K.
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- Large-scale synthesis of β-L-fucopyranosyl phosphate and the preparation of GDP-β-L-fucose
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A practical 15-mmol large-scale synthesis of β-L-fucopyranosyl dicyclohexylammonium phosphate from L-fucose in 63percent overall yield was developed.The synthesis took advantage of a neighboring Bz-2 group participating in a Koenigs-Knorr like glycosylati
- Adelhorst, Kim,Whitesides, George M.
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- Preparation and Antileukemic Screening of Some New 6'-Deoxyhexopyranosyladenine Nucleosides
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9-β-D-Fucopyranosyladenine (1) has weak antileukemic activity against L1210 cells grown in culture.Several new 6'-deoxyhexopyranosyladenine nucleosides were synthesized by standard procedures and assayed for activity.The new nucleosides were 9-(6-deoxy-β-
- Lerner, Leon M.,Sheid, Bertrum,Gaetjens, Eric
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p. 1521 - 1525
(2007/10/02)
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- DERIVATIVES OF 6-DEOXY-L-TALOSE AND THE SYNTHESIS OF 6-DEOXY-2-O-(α-L-RHAMNOPYRANOSYL)-L-TALOSE
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Benzyl 6-deoxy-α-L-talopyranoside (10) has been synthesized and provides, after hydrogenolysis, an improved preparation of 6-deoxy-L-talose.Several partially substituted derivatives of the glycoside 10 have been prepared, including benzyl 6-deoxy-3,4-O-is
- Aspinall, Gerald O.,Takeo, Ken'ichi
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- Synthesis and antitumor activity of analogues of the antitumor antibiotic chartreusin
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First isolated in 1953 from a fermentation broth, chartreusin (1) has received interest as a result of substantial antitumor activities recently demonstrated in several murine test systems. Poor water solubility frustrated formulation attempts, and rapid
- Takai,Uehara,Beisler
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p. 549 - 553
(2007/10/02)
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