HPLC-assisted automated oligosaccharide synthesis: the implementation of the two-way split valve as a mode of complete automation

Chemical Communications, Journal Year: 2020, Volume and Issue: 56(9), P. 1333 - 1336

Published: Jan. 1, 2020

Reported herein is the development of a user-friendly platform for simple and transformative automation based on standard HPLC equipment.

Language: Английский

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Studies of Catalyst-Controlled Regioselective Acetalization and Its Application to Single-Pot Synthesis of Differentially Protected Saccharides

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(44), P. 18592 - 18604

Published: Oct. 27, 2021

This article describes studies on the regioselective acetal protection of monosaccharide-based diols using chiral phosphoric acids (CPAs) and their immobilized polymeric variants, (R)-Ad-TRIP-PS (S)-SPINOL-PS, as catalysts. These catalyst-controlled acetalizations were found to proceed with high regioselectivities (up >25:1 rr) various d-glucose-, d-galactose-, d-mannose-, l-fucose-derived 1,2-diols could be carried out in a regiodivergent fashion depending choice catalyst. The catalysts conveniently recycled reused multiple times for gram-scale functionalizations catalytic loadings low 0.1 mol %, performance was often superior monomeric variants. CPA-catalyzed successfully combined common hydroxyl group single-pot telescoped procedures produce 32 regioisomerically pure differentially protected mono- disaccharide derivatives. To further demonstrate utility catalysts, same batch catalyst accomplish syntheses 6 d-glucose subsequent exploration reaction mechanism NMR deuterated nondeuterated substrates revealed that low-temperature happen via syn-addition regioselectivity exhibits strong dependence temperature. computational indicate complex temperature-dependent interplay two mechanisms, one involving an anomeric phosphate intermediate another concerted asynchronous formation acetal, results products. models also explain steric factors responsible observed C2 selectivities are consistent experimentally selectivity trends.

Language: Английский

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Design, Synthesis and Biological Activity of Novel Methoxy- and Hydroxy-Substituted N-Benzimidazole-Derived Carboxamides

Molecules, Journal Year: 2024, Volume and Issue: 29(9), P. 2138 - 2138

Published: May 4, 2024

This work presents the design, synthesis and biological activity of novel N-substituted benzimidazole carboxamides bearing either a variable number methoxy and/or hydroxy groups. The targeted were designed to investigate influence groups, type substituent placed on N atom core activity. most promising derivatives with pronounced antiproliferative proved be N-methyl-substituted hydroxyl groups at phenyl ring cyano nuclei selective against MCF-7 cell line (IC50 = 3.1 μM). In addition, cyano-substituted 10 11 showed strong tested cells 1.2–5.3 Several compounds significantly improved antioxidative in all three methods compared standard BHT. 9, 10, 32 36 generally confirmed their antioxidant ability demonstrated vitro. However, was not related inhibit oxidative stress nor induce it. Compound 8 two one group strongest antibacterial Gram-positive strain E. faecalis (MIC

Language: Английский

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β-N-Acetylhexosaminidases—the wizards of glycosylation

Applied Microbiology and Biotechnology, Journal Year: 2019, Volume and Issue: 103(19), P. 7869 - 7881

Published: Aug. 10, 2019

Language: Английский

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A Hitchhiker’s Guide to Problem Selection in Carbohydrate Synthesis

ACS Central Science, Journal Year: 2023, Volume and Issue: 9(7), P. 1285 - 1296

Published: July 12, 2023

Oligosaccharides are ubiquitous in molecular biology and used for functions ranging from governing protein folding to intercellular communication. Perhaps paradoxically, the exact role of glycan most these settings is not well understood. One reason this contradiction concerns fact that carbohydrates often appear heterogeneous form nature. These mixtures complicate isolation pure material characterization structure–activity relationships. As a result, major bottleneck glycoscience research synthesis modification materials. While synthetic chemoenzymatic methods have enabled access homogeneous tool compounds, central problem, particularly newer chemists, matter problem selection. This outlook aims provide an entry level overview fundamental principles carbohydrate chemistry with eye toward enabling solutions frontier challenges.

Language: Английский

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Catalytic Regioselective Benzoylation of 1,2-trans-Diols in Carbohydrates with Benzoyl Cyanide: The Axial Oxy Group Effect and the Action of Achiral and Chiral Amine Catalysts

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(19), P. 11406 - 11416

Published: Sept. 9, 2020

Regioselective protection of the polyfunctional carbohydrates with acyl groups under catalytic conditions is a prerequisite for efficient structural modification and chain extension via glycosidation. A general also strong "axial oxy group effect" was now observed benzoyl cyanide as acylating agent 4-dimethylaminopyridine catalyst, permitting preferred O-acylation equatorial hydroxy next to axial groups. This effect substantiated 2,3-O-unprotected β-d-galacto- α-d-glucopyranosides 3,4-O-unprotected mannopyranosides possessing vicinal trans-diol moieties. Moreover, trans-diols each group, expectedly comparable reactivity, could be differentiated chiral tertiary amine catalysts. Particularly interesting in this regard action bifunctional (S,S)-N-(N,N-dialkylaminocyclohexyl)-thioureas catalysts; they favor 2-O-benzoylation α-galactopyranosides, supported by density functional theory calculations. directing can reversed quinidine catalyst or bulky substituents at anomeric position.

Language: Английский

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Photolabile Protecting Group‐Mediated Synthesis of 2‐Deoxy‐Glycosides

Chinese Journal of Chemistry, Journal Year: 2021, Volume and Issue: 39(12), P. 3309 - 3314

Published: Aug. 30, 2021

Main observation and conclusion A green efficient photolabile protecting group (PPG)‐mediated glycosidation approach for the synthesis of 2‐deoxy‐glycosides is reported. By employing ortho ‐nitrobenzyl carbonate ( o NBC) as PPG, N , ‐dimethylformamide (DMF)‐modulated SPhosAuNTf 2 ‐promoted with per‐ NBC‐protected 2‐deoxy‐glycosyl ynenoates affords moderate to excellent α‐selectivities presumably depending on reactivities acceptor alcohols. Based PPG‐mediated approach, oligosaccharides three six NBC groups are effectively achieved. The multiple in completely cleaved by irradiation at 365 nm, resulting desired an manner without affecting common alkyne, alkene, azide functional traditional aglycones.

Language: Английский

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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

Chemistry - A European Journal, Journal Year: 2019, Volume and Issue: 25(71), P. 16277 - 16287

Published: Sept. 11, 2019

Abstract Group B Streptococcus serotypes Ia and Ib capsular polysaccharides are key targets for vaccine development. In spite of their immunospecifity these share high structural similarity. Both composed the same monosaccharide residues differ only in connection Neu5Acα2‐3Gal side chain to GlcNAc unit, which is a β1‐4 linkage serotype β1‐3 Ib. The development efficient regioselective routes GlcNAcβ1‐3[Glcβ1‐4]Gal synthons described, give access different group (GBS) repeating unit frameshifts. These glycans were used probe conformation molecular dynamics two polysaccharides, highlighting presentation protruding moieties on polysaccharide backbones higher flexibility polymer relative Ia, can impact epitope exposure.

Language: Английский

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Photolabile ortho‐Nitro‐Benzyl Carbonate as a Permanent Hydroxyl Protecting Group for the Synthesis of Digalactosyl Diacylglycerol

Chinese Journal of Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 16, 2024

Comprehensive Summary Traditional protecting groups are often removed under harsh conditions with potentially hazardous reagents, thereby impeding the convenient synthesis of oligosaccharides and glycosides. Herein, we present to utilize photolabile ortho ‐nitro‐benzyl carbonate ( o NBC) as a permanent hydroxyl group for stereocontrolled The Ph 3 PO‐modulated glycosylation strongly disarmed per‐ O ‐ NBC‐protected glycosyl ynenoates preferred afford glycosides excellent α‐selectivities via β‐phosphonium transition state. Based on NBC‐mediated galactosylation, glycolipid digalactosyl diacylglycerol (DGDG) containing six double bonds two esters was achieved in straightforward manner.

Language: Английский

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Calorimetric Analysis of the Interplay between Synthetic Tn Antigen-Presenting MUC1 Glycopeptides and Human Macrophage Galactose-Type Lectin

Biochemistry, Journal Year: 2021, Volume and Issue: 60(7), P. 547 - 558

Published: Feb. 9, 2021

Human macrophage galactose-type lectin (hMGL, HML, CD301, CLEC10A), a C-type expressed by dendritic cells and macrophages, is receptor for N-acetylgalactosamine α-linked to serine/threonine residues (Tn antigen, CD175) its α2,6-sialylated derivative (sTn, CD175s). Because these two epitopes are among malignant cell glycan displays, particularly when presented mucin-1 (MUC1), assessing the influence of site frequency glycosylation on recognition will identify determinants governing this interplay. Thus, chemical synthesis tandem-repeat O-glycan acceptor region MUC1 site-specific threonine in all permutations were carried out. Isothermal titration calorimetry (ITC) analysis binding hMGL library glycopeptides revealed an enthalpy-driven process affinity enhancement order magnitude with increasing count from 6–8 μM monoglycosylated peptides 0.6 triglycosylated peptide. ITC measurements performed D2O permitted further exploration solvation dynamics during binding. A shift enthalpy–entropy compensation contact position-specific effects likely involvement peptide surroundings detected. KinITC prolonged lifetime lectin–glycan complex valency change solvent D2O.

Language: Английский

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