Dimethyl disulfide reacts with triflic anhydride to provide a highly reactive electrophile. Various thioglycosides, differing in their thio aglycons, carbohydrate units, and protecting group pattern, were activated with Me2S2-Tf2O in the presence of different glycosyl acceptors. The reactions proceeded at low temperatures within a short time, affording oligosaccharides in high yields both on primary and secondary hydroxyls. Armed and disarmed glycosyl donors were activated equally efficiently.
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http://dx.doi.org/10.1021/ol702139u | DOI Listing |
Chem Rec
December 2024
Qiandongnan Traditional Medicine Research & Development Center, School of Life and Health Science, Kaili University, 3 Kaiyuan Road, Qiandongnan Miao and Dong Autonomous Prefecture, Kaili, 556011, China.
Carbohydrates are natural, renewable, chemical compounds that play crucial roles in biological systems. Thus, efficient and stereoselective glycosylation is an urgent task for the preparation of pure and structurally well-defined carbohydrates. Photoredox catalysis has emerged as a powerful tool in carbohydrate chemistry, providing an alternative for addressing some of the challenges of glycochemistry.
View Article and Find Full Text PDFAnal Chem
December 2024
State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
A dual-SERS encoding strategy was designed for in situ and in vivo evaluation of multiplex protein-specific glycosylation of tumors. The dual-SERS encoding strategy consisted of two pairs of dual gold nanoprobes with different diameters of 10 and 30 nm, which were encoded with four different and distinguishable Raman signal molecules. The 10 and 30 nm gold nanoprobes (Au10 and Au30 probes, respectively) were further modified with lectins and aptamers to recognize the target glycans and proteins, respectively.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
Globo H, a specific carbohydrate antigen overexpressed on various human malignancies, has attracted considerable interest as an antigenic target for anticancer vaccine development. Despite several Globo H-based carbohydrate vaccines that have been designed, efficient access to Globo H hexasaccharide antigen and development of powerful adjuvants for enhancing antitumor immunity remain challenging. Herein, we reported a streamlined chemoenzymatic approach to prepare this hexasaccharide antigen, relying on chemical synthesis of Gb5 pentasaccharide by a stereoconvergent [2+3] strategy and subsequent enzymatic α-fucosylation to easily install α1,2-fucose residue.
View Article and Find Full Text PDFCarbohydr Polym
January 2025
Integrative Biology of Marine Models (LBI2M), UMR8227, Station Biologique de Roscoff (SBR), CNRS, Sorbonne Université, 29680 Roscoff, France.
Carrageenans are major gel forming polysaccharides in the extracellular matrix of the red macroalga Chondrus crispus. These galactans are made of linear chains of repetitive disaccharide motifs based on d-galactose residues alternately linked by β-1,4 and α-1,3 glycosidic bonds. A definite number of disaccharide motifs are known, based on their regular sulfations and the presence of a 3,6-anhydro bridge.
View Article and Find Full Text PDFEur J Med Chem
January 2025
Department of Organic Chemistry, Faculty of Chemistry, University of Seville, E-41012, Seville, Spain. Electronic address:
Invariant natural killer T (iNKT) cells are a subset of innate T cells displaying powerful immunomodulatory functions. Despite extensive preclinical research on the use of iNKT agonist and antagonist for various diseases, translating these findings into successful clinical applications has proven challenging, leaving no approved treatments to date. Efforts to optimize therapeutic outcomes by developing alternative glycolipids to α-galactosylceramide (α-GalCer or KRN7000), the prototypical iNKT antigen, have shown improved preclinical results.
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