- Total Synthesis of Tri-, Hexa- and Heptasaccharidic Substructures of the O-Polysaccharide of Providencia rustigianii O34
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A general and efficient strategy for synthesis of tri-, hexa- and heptasaccharidic substructures of the lipopolysaccharide of Providencia rustigianii O34 is described. For the heptasaccharide seven different building blocks were employed. Special features of the structures are an α-linked galactosamine and the two embedded α-fucose units, which are either branched at positions-3 and -4 or further linked at their 2-position. Convergent strategies focused on [4+3], [3+4], and [4+2+1] couplings. Whereas the [4+3] and [3+4] coupling strategies failed the [4+2+1] strategy was successful. As monosaccharidic building blocks trichloroacetimidates and phosphates were employed. Global deprotection of the fully protected structures was achieved by Birch reaction.
- Ahadi, Somayeh,Awan, Shahid I.,Werz, Daniel B.
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- PROTECTED TETRASACCHARIDES, THEIR PROCESS OF PREPARATION AND THEIR USE AS TRANSGLUCOSYLASE ACCEPTOR SUBSTRATES IN THE CHEMO-ENZYMATIC SYNTHESIS OF SHIGELLA FLEXNERI SPECIFIC OLIGOSACCHARIDES
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The present invention provides protected tetrasaccharides, their process of preparation and their use in the synthesis of oligosaccharides, in particular fragments of O-antigens from Shigella flexneri, for example of serotype la, lb, 2a, 2b, 3a, X, 4a, 4b
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Page/Page column 38
(2019/01/21)
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- Synthesis and Structure-Activity Relationship Study of Antimicrobial Auranofin against ESKAPE Pathogens
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Auranofin, an FDA-approved arthritis drug, has recently been repurposed as a potential antimicrobial agent; it performed well against many Gram-positive bacteria, including multidrug resistant strains. It is, however, inactive toward Gram-negative bacteria, for which we are in dire need of new therapies. In this work, 40 auranofin analogues were synthesized by varying the structures of the thiol and phosphine ligands, and their activities were tested against ESKAPE pathogens. The study identified compounds that exhibited bacterial inhibition (MIC) and killing (MBC) activities up to 65 folds higher than that of auranofin, making them effective against Gram-negative pathogens. Both thiol and the phosphine structures influence the activities of the analogues. The trimethylphosphine and triethylphosphine ligands gave the highest activities against Gram-negative and Gram-positive bacteria, respectively. Our SAR study revealed that the thiol ligand is also very important, the structure of which can modulate the activities of the AuI complexes for both Gram-negative and Gram-positive bacteria. Moreover, these analogues had mammalian cell toxicities either similar to or lower than that of auranofin.
- Wu, Bin,Yang, Xiaojian,Yan, Mingdi
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supporting information
p. 7751 - 7768
(2019/09/10)
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- Total Synthesis of a Densely Functionalized Plesiomonas shigelloides Serotype 51 Aminoglycoside Trisaccharide Antigen
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Plesiomonas shigelloides, a pathogen responsible for frequent outbreaks of severe travelers' diarrhea, causes grave extraintestinal infections. Sepsis and meningitis due to P. shigelloides are associated with a high mortality rate as antibiotic resistance increases and vaccines are not available. Carbohydrate antigens expressed by pathogens are often structurally unique and are targets for developing vaccines and diagnostics. Here, we report a total synthesis of the highly functionalized trisaccharide repeating unit 2 from P. shigelloides serotype 51 from three monosaccharides. A judicious choice of building blocks and reaction conditions allowed for the four amino groups adorning the sugar rings to be installed with two N-acetyl (Ac) groups, rare acetamidino (Am), and d-3-hydroxybutyryl (Hb) groups. The strategy for the differentiation of amino groups in trisaccharide 2 will serve well for the syntheses of other complex glycans.
- Qin, Chunjun,Schumann, Benjamin,Zou, Xiaopeng,Pereira, Claney L.,Tian, Guangzong,Hu, Jing,Seeberger, Peter H.,Yin, Jian
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p. 3120 - 3127
(2018/03/08)
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- Glycoconjugates and use thereof as vaccine against Shigella flexneri serotype 3a and X
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The present invention relates to compounds derived from sugars which reproduce the epitopes of Shigella flexneri serotypes 3a and X and to the use thereof for the preparation of vaccine compositions. More specifically, the subject matter of the present in
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Page/Page column 29
(2014/09/03)
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- Modular automated solid phase synthesis of dermatan sulfate oligosaccharides
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Dermatan sulfates are glycosaminoglycan polysaccharides that serve a multitude of biological roles as part of the extracellular matrix. Orthogonally protected d-galactosamine and l-iduronic acid building blocks and a photo-cleavable linker are instrumental for the automated synthesis of dermatan sulfate oligosaccharides. Conjugation-ready oligosaccharides were obtained in good yield.
- Kandasamy, Jeyakumar,Schuhmacher, Frank,Hahm, Heung Sik,Klein, James C.,Seeberger, Peter H.
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supporting information
p. 1875 - 1877
(2014/02/14)
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- Prednisolone succinate-glucosamine conjugate: Synthesis, characterization and in vitro cellular uptake by kidney cell lines
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Prednisolone succinate-glucosamine (PSG) conjugate, a prodrug for prednisolone, was synthesized and confirmed by NMR and MS spectrum. The stabilities of the prodrug in PBS (pH 2.50, 5.00, 7.20, and 7.89) were studied. Cytotoxicity and uptake assay of the prodrug were perfomed on HK-2 and MDCK cell lines. The results showed that compared with prednisolone, the PSG not only did not increase the cytotoxicity but also improved the uptake to 2.2 times of prednisolone by the cells. Thus, it indicated that glucosamine might be a potential carrier for kidney-targeting delivery of prednisolone.
- Lin, Yan,Sun, Xun,Gong, Tao,Zhang, Zhi Rong
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scheme or table
p. 25 - 28
(2012/04/04)
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- Synthesis and scalable conversion of L-iduronamides to heparin-related Di- and tetrasaccharides
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A diastereomerically pure cyanohydrin, preparable on kilogram scale, is efficiently converted in one step into a novel L-iduronamide. A new regioselective acylation of this iduronamide and a new mild amide hydrolysis method mediated by amyl nitrite enable
- Hansen, Steen U.,Miller, Gavin J.,Barath, Marek,Broberg, Karl R.,Avizienyte, Egle,Helliwell, Madeleine,Raftery, James,Jayson, Gordon C.,Gardiner, John M.
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p. 7823 - 7843
(2013/01/15)
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- Multi-gram synthesis of a hyaluronic acid subunit and synthesis of fully protected oligomers
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Fully protected tetra-, hexa- and octasaccharides of hyaluronic acid were synthesized on a scale of several 100 mg up to gram quantities using allyl (methyl 2-O-benzoyl-3-O-benzyl-4-O-levulinoyl-β-D-glucopyranosyluronate)- (1→3)-4-O-acetyl-6-O-benzyl-2-deoxy-2-trichloroacetamido-β-D- glucopyranoside as a key building block. This disaccharide was subjected to deprotection, then glycosylation via the trichloroacetimidate method was employed to achieve the formation of the oligosaccharides.
- Virlouvet, Mickael,Gartner, Michael,Koroniak, Katarzyna,Sleeman, Jonathan P.,Braese, Stefan
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supporting information; experimental part
p. 2657 - 2662
(2011/01/05)
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- CARBOHYDRATE BASED TOLL-LIKE RECEPTOR (TLR) ANTAGONISTS
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The invention provides carbohydrate based compounds, methods of preparation, and compositions useful for modulating signaling through Toll-like receptors. The methods involve contacting a TLR-expressing cell with a carbohydrate based compound of the inven
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Page/Page column 21
(2009/09/07)
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- The use of 2-deoxy-2-trichloroacetamido-D-glucopyranose derivatives in syntheses of oligosaccharides
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3,4,6-Tri-O-acetyl-2-deoxy-2-trichloroacetamido-α-D-glucopyranosyl trichloroacetimidate and its O-benzylated analogue were tested as glycosyl donors in the reaction with a set of sugar acceptors unsubstituted on O-3 and O-4, typically encountered in the s
- Blatter, Geraldine,Beau, Jean-Marie,Jacquinet, Jean-Claude
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p. 189 - 202
(2007/10/02)
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