- Phenyl glycosides – Solid-state NMR, X-ray diffraction and conformational analysis using genetic algorithm
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The X-ray structures of 2,6-dimethylphenyl and phenyl 2,3,4,6-tetra-O-acetyl β-glucosides (1 and 3) and phenyl α-mannoside (6) were obtained. The independent part of the unit cell of the glycosides 1 and 6 was formed by one molecule, and for the glucoside 3, two molecules in the crystal cell were observed. In deacetylated glycosides 4 and 6 the crystal structure was established by a hydrogen bond network formed between the sugar hydroxyls and solvent molecules. The 13C CPMAS NMR spectra of aryl glycosides 1–6 were analysed. In the spectrum of 3, doubling of the C4 aryl signal was observed which confirmed the presence of two independent molecules in the solid sample. The GAAGS (Genetic Algorithm-Assisted Grid Search) method was used to determine the low-energy conformers of α-mannosides and β-glucosides. The orientation of the aryl pendant group was calculated using Molecular Mechanics (MMFF94) as well as Quantum Mechanics theory (DFT, B3LYP/6-31 + G(d,p)).
- Wa?ejko, Piotr,Bukowicki, Jaros?aw,Dobrzycki, ?ukasz,Socha, Pawe?,Paradowska, Katarzyna
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p. 126 - 136
(2019/01/03)
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- Structure-based discovery of glycomimetic FmlH ligands as inhibitors of bacterial adhesion during urinary tract infection
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Treatment of bacterial infections is becoming a serious clinical challenge due to the global dissemination of multidrug antibiotic resistance, necessitating the search for alternative treatments to disarm the virulence mechanisms underlying these infections. Uropathogenic Escherichia coli (UPEC) employs multiple chaperone- usher pathway pili tipped with adhesins with diverse receptor specificities to colonize various host tissues and habitats. For example, UPEC F9 pili specifically bind galactose or N-acetylgalactosamine epitopes on the kidney and inflamed bladder. Using X-ray structureguided methods, virtual screening, and multiplex ELISA arrays, we rationally designed aryl galactosides and N-acetylgalactosaminosides that inhibit the F9 pilus adhesin FmlH. The lead compound, 29β-NAc, is a biphenyl N-acetyl-β-galactosaminoside with a Ki of ～90 nM, representing a major advancement in potency relative to the characteristically weak nature of most carbohydrate-lectin interactions. 29β-NAc binds tightly to FmlH by engaging the residues Y46 through edge-to-face π-stacking with its A-phenyl ring, R142 in a salt-bridge interaction with its carboxylate group, and K132 through watermediated hydrogen bonding with its N-acetyl group. Administration of 29β-NAc in a mouse urinary tract infection (UTI) model significantly reduced bladder and kidney bacterial burdens, and coadministration of 29β-NAc and mannoside 4Z269, which targets the type 1 pilus adhesin FimH, resulted in greater elimination of bacteria from the urinary tract than either compound alone. Moreover, FmlH specifically binds healthy human kidney tissue in a 29β-NAc-inhibitable manner, suggesting a key role for F9 pili in human kidney colonization. Thus, these glycoside antagonists of FmlH represent a rational antivirulence strategy for UPEC-mediated UTI treatment.
- Kalas, Vasilios,Hibbing, Michael E.,Maddirala, Amarendar Reddy,Chugani, Ryan,Pinkner, Jerome S.,Mydock-McGrane, Laurel K.,Conover, Matt S.,Janetka, James W.,Hultgren, Scott J.
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p. E2819 - E2828
(2018/03/27)
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- Stereocontrolled Synthesis of Phenolic α-d-Glycopyranosides
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Adopting the ‘remote activation concept’ toward stereocontrolled glycoside synthesis with minimal use of protection groups, a general synthesis of phenolic 1,2-cis glycopyranosides is reported, as exemplified by aryl α-d-galacto-, α-d-gluco- and 2-azido α-d-glucopyranosides among others using glycosyl donors bearing an anomeric (3-bromo-2-pyridyloxy) group and catalyzed by methyl triflate.
- St-Pierre, Gabrielle,Dafik, Laila,Klegraf, Ellen,Hanessian, Stephen
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p. 3575 - 3588
(2016/10/17)
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- COMPOUNDS AND METHODS FOR TREATING BACTERIAL INFECTIONS
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The present invention encompasses compounds and methods for treating urinary tract infections.
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Page/Page column 69-70
(2011/05/06)
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- FimH antagonists for the oral treatment of urinary tract infections: From design and synthesis to in vitro and in vivo evaluation
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Urinary tract infection (UTI) by uropathogenic Escherichia coli (UPEC) is one of the most common infections, particularly affecting women. The interaction of FimH, a lectin located at the tip of bacterial pili, with high mannose structures is critical for the ability of UPEC to colonize and invade the bladder epithelium. We describe the synthesis and the in vitro/in vivo evaluation of α-d-mannosides with the ability to block the bacteria/host cell interaction. According to the pharmacokinetic properties, a prodrug approach for their evaluation in the UTI mouse model was explored. As a result, an orally available, low molecular weight FimH antagonist was identified with the potential to reduce the colony forming units (CFU) in the urine by 2 orders of magnitude and in the bladder by 4 orders of magnitude. With FimH antagonist 16b, the great potential for the effective treatment of urinary tract infections with a new class of orally available antiinfectives could be demonstrated.
- Klein, Tobias,Abgottspon, Daniela,Wittwer, Matthias,Rabbani, Said,Herold, Janno,Jiang, Xiaohua,Kleeb, Simon,Lüthi, Christine,Scharenberg, Meike,Bezen?on, Jacqueline,Gubler, Erich,Pang, Lijuan,Smiesko, Martin,Cutting, Brian,Schwardt, Oliver,Ernst, Beat
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supporting information; experimental part
p. 8627 - 8641
(2011/02/28)
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- Elucidation of the mechanism of polysaccharide cleavage by chondroitin AC lyase from Flavobacterium heparinum
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Chondroitin AC lyase from Flavobacterium heparinum degrades chondroitin sulfate glycosaminoglycans via an elimination mechanism resulting in disaccharides or oligosaccharides with Δ4,5-unsaturated uronic acid residues at their nonreducing end. Mechanistic details concerning the ordering of the bond-breaking and -forming steps of this enzymatic reaction are nonexistent, mainly due to the inhomogeneous nature of the polymeric substrates. The creation of a new class of synthetic substrates for this enzyme has allowed the measurement of defined and reproducible kcat and Km values and has expanded the range of mechanistic studies that can be performed. The primary deuterium kinetic isotope effect upon kcat/Km for the abstraction of the proton α to the carboxylic acid was measured to be 1.67 ± 0.07, showing that deprotonation occurs in a rate-limiting step. Using substrates with leaving groups of differing reactivity, a flat linear free energy relationship was produced, indicating that the C4-O4 bond is not broken in a rate-determining step. Taken together, these results strongly suggest a stepwise mechanism. Consistent with this was the measurement of a secondary deuterium kinetic isotope effect upon kcat/Km of 1.01 ± 0.03 on a 4-{2H}-substrate, indicating that no sp2 character is developed at C4 during the rate-limiting step, thereby ruling out a concerted syn-elimination.
- Rye, Carl S.,Withers, Stephen G.
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p. 9756 - 9767
(2007/10/03)
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- Process for the preparation of tetrahydropyran derivatives
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A process of making arbutin and its derivatives comprises solvolyzing an acylated precursor of arbutin or its derivative in a solution comprising an organic solvent and a base, neutralizing the solution with an acid, and crystillizing the product arbutin or its derivative. The process may be employed on an industrial scale and avoids the use of ion exchange columns. The process has the advantages of not requiring ion exchange columns and peripheral devices, which leads to cost and time savings, due to the elimination of column regeneration steps. Waste water from column regeneration is also eliminated.
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- Stannic chloride promoted synthesis of mannosides
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Use of anhyd.SnCl4 has been described for the synthesis of aryl, arylalkyl and alkyl α-D-mannopyranosides.A possible mechanism for the formation of α-anomer in these reactions is discussed.
- Irani, Rustom K,Sinha, Bharati,Bose, J L
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p. 519 - 521
(2007/10/02)
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