- Zwitterionic Polysaccharides of Shigella sonnei: Synthetic Study toward a Ready-for-Oligomerization Building Block Made of Two Rare Amino Sugars
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Shigellosis is an endemic diarrheal disease caused by Gram negative bacteria named Shigella. The most exposed polysaccharides of Shigella sonnei display a zwitterionic disaccharide repeating unit (AB) made of two rare amino sugars: [4)-α- l -Alt p NAcA-(1→3)-β- d -Fuc p NAc4N-(1→]. An original synthesis of a ready-for-oligomerization AB disaccharide is reported. The targeted orthogonally protected disaccharide was synthesized from l -glucose and tetra- O -acetyl-β- d -glucosamine. The challenging introduction of the 4 B -azido group masking the amino moiety of the AAT residue was performed at the disaccharide stage by a two-step procedure (triflation followed by nucleoaphilic displacement with NaN 3). A post-glycosylation oxidation strategy was employed to access the altruronate moiety.
- Pfister, Hélène B.,Paoletti, Julie,Poveda, Ana,Jimenez-Barbero, Jesus,Mulard, Laurence A.
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- Regioselective Glycosylation Strategies for the Synthesis of Group Ia and Ib Streptococcus Related Glycans Enable Elucidating Unique Conformations of the Capsular Polysaccharides
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Group B Streptococcus serotypes Ia and Ib capsular polysaccharides are key targets for vaccine development. In spite of their immunospecifity these polysaccharides share high structural similarity. Both are composed of the same monosaccharide residues and
- Del Bino, Linda,Calloni, Ilaria,Oldrini, Davide,Raso, Maria Michelina,Cuffaro, Rossella,Ardá, Ana,Codée, Jeroen D. C.,Jiménez-Barbero, Jesús,Adamo, Roberto
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p. 16277 - 16287
(2019/11/14)
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- NOVEL INTERMEDIATES FOR THE PREPARATION OF GBS POLYSACCHARIDE ANTIGENS
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The present invention generally refers to novel intermediate polysaccharide units, useful for the preparation of polysaccharide antigen of GBS Ia, Ib and III; the invention also refers to a process for their preparation and their use as intermediate for t
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Paragraph 0066-0068
(2019/01/30)
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- Ionic-liquid supported rapid synthesis of an: N -glycan core pentasaccharide on a 10 g scale
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A new and efficient Ionic Liquid-Supported Oligosaccharide Synthesis (ILSOS) strategy for an N-linked core pentasaccharide on a 10 g scale is reported. This new ILSOS includes a new spacer for an IL support, a new tagging strategy, and fast, efficient and orthogonal removal of the ionic-liquid support, producing the N-linked core pentasaccharide with direct applicability potential in a short time, with high yield and on a large gram scale.
- Li, Wei,Gao, Yu,Li, Qing,Li, Zhong-Jun
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p. 4720 - 4727
(2018/07/06)
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- Synthesis and immunological characterization of modified hyaluronic acid hexasaccharide conjugates
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The synthesis of a tetanus toxoid (TT)-conjugate of a hyaluronic acid (HA) hexasaccharide is described. The compound was intended for use in monitoring HA levels as a disease marker and as a potential vaccine against Group A Streptococcus (GAS) infections. We also report the synthesis of a chemically modified HA-hexasaccharide-TT conjugate in which the N-acetyl moiety of the N-acetyl-d-glucosamine residue is replaced with an N-propionyl unit in order to enhance immunogenicity. The oligosaccharides are synthesized in a convergent manner. The TT-conjugate syntheses rely on the reaction of the amines on the 6-aminohexyl aglycon of the hexasaccharides with diethyl squarate to give the monoethyl squarate adducts. Subsequent reactions with lysine ε-amino groups on TT then give the glycoconjugates containing an average of 8 hexasaccharide haptens per TT molecule. Immunological studies in mice show very similar antibody responses with both conjugates, suggesting that the N-acetyl groups of the glucosaminyl residues of the HA-hexasaccharide are not a critical part of the epitope recognized by the anti-HA polyclonal immune response. Furthermore, it would appear that the N-acyl moieties are not in close contact with the amino acid residues of the antibody combining sites.
- Gu, Guofeng,Adabala, Pal John Pal,Szczepina, Monica G.,Borrelli, Silvia,Pinto, B. Mario
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p. 8004 - 8019
(2013/09/12)
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- Glycosyl N-tosyl benzimidate as a new building block for chemical glycosylation
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Seven novel glycosyl N-tosyl benzimidates were prepared by the reactions of the corresponding hemiacetals with imidoyl chloride in 55-88% yields, which were smoothly converted to glycosides, upon treatment with alcohols and catalytic TMSOTf, in 57-99% yields. Georg Thieme Verlag Stuttgart · New York.
- Liu, Shaojing,Peng, Yannan,Wang, Peng,Li, Ming
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p. 1501 - 1504
(2012/07/27)
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- Preparation of Thiosugars and Their Use
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A process for the preparation of a thiosaccharide represented by Saccharide-S-H wherein Saccharide comprises at least 4 sugar units, comprises subjecting a corresponding compound of the formula (P)Saccharide-S-(P) wherein (P) represents an O- or S-protecting group(s), to Birch reduction.
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Page/Page column 4; 19-20
(2009/07/18)
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- InCl3 as a powerful catalyst for the acetylation of carbohydrate alcohols under microwave irradiation
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Indium(III) chloride catalyzed microwave assisted acetylation of different carbohydrates is an efficient synthesis of per-O-acetyl derivatives and provides the products in good to excellent yields.
- Das, Saibal Kumar,Reddy, K. Anantha,Krovvidi, V. L. Narasimha Rao,Mukkanti
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p. 1387 - 1392
(2007/10/03)
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- Sugars within a hydrophobic scaffold: Glycodendrimers from polyphenylenes
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(Chemical Equation Presented) A new glycodendrimer type has been introduced that is designed on the basis of shape-persistent polyphenylene dendrimers. The sugar installation occurs not only on the dendrimer surface but also within the hydrophobic internal scaffold. The synthesis has been accomplished via both convergent and divergent routes by employing the Schmidt glycosylation and the Diels-Alder reaction. This new glycodendrimer has been found to exhibit water-solubility, while conserving hydrophobicity of the interior environment despite the incorporation of sugars.
- Sakamoto, Junji,Muellen, Klaus
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p. 4277 - 4280
(2007/10/03)
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- Conversion of p-methoxyphenyl glycosides into the corresponding glycosyl chlorides and bromides, and into thiophenyl glycosides
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p-Methoxyphenyl (pMP) β-D-glycopyranosides (Glc, Gal, GlcNPhth, GalNPhth, GlcNTroc, Galβ4Glc, Galα4Gal) were prepared from the corresponding 1-O-acetyl sugars in 79-90% yield, using boron trifluoride etherate as promoter. Treatment of the pMP glycosides with acyl chlorides or bromides in the presence of various Lewis acids gave the corresponding glycosyl chlorides and bromides in 81-98% yield. Treatment of the acyl-protected pMP glycosides with thiophenol and boron trifluoride etherate gave the corresponding thioglycosides in 80-100% yield and high (> 20:1) β/α selectivity. The stability of pMP glycosides was investigated against a series of reagents.
- Zhang, Zhiyuan,Magnusson, Goeran
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- Synthesis of sulfated glucuronyl glycosphingolipids; carbohydrate epitopes of neural cell-adhesion molecules
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The sulfated glucuronyl glycosphingolipids isolated from the human peripheral nervous system, HO3S-3-β-GlcpA-(1 → 3)-{β-D-Galp-(1 → 4)-β-D-GlcpNAc-(1 → 3)}(n)-β-D-Galp-(1 → 4)-β-D-Glcp-(1 → 1)-Cer (n = 1, 2) (1 and 2) were synthesized. The glyc
- Nakano,Ito,Ogawa
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- Total synthesis of a sulfated glucuronyl glycosphingolipid, IV3GlcA(3-SO3)nLcOse4Cer, a carbohydrate epitope of neural cell adhesion molecules
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A total synthesis of a sulfated glucuronyl glycosphingolipid isolated from human peripheral nervous system was achieved for the first time.
- Nakano, Takahisa,Ito, Yukishige,Ogawa, Tomoya
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p. 1597 - 1600
(2007/10/02)
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