Disaccharide-derived 2-oxo- and 2-oximinoglycosyl bromides: novel, conveniently accessible building blocks for the expedient construction of oligosaccharides with .alpha.-D-glucosamine, .beta.-D-mannose, and .beta.-D-mannosamine as constituent sugars
monoglycoside of 2-phenylethanol to investigate the substrate specificity of the purified beta-primeverosidase from fresh leaves of a tea cultivar (Camellia sinensis var. sinensis cv. Yabukita) in comparison with the apparent substrate specificity of the crude enzyme extract from tea leaves. The crude enzyme extract mainly showed beta-primeverosidase activity, although monoglycosidases activity was present
作者:Lisa M. Doyle、Shane O’Sullivan、Claudia Di Salvo、Michelle McKinney、Patrick McArdle、Paul V. Murphy
DOI:10.1021/acs.orglett.7b02760
日期:2017.11.3
Glycosyl thiols are widely used in stereoselective S-glycoside synthesis. Their epimerization from 1,2-trans to 1,2-cis thiols (e.g., equatorial to axial epimerization in thioglucopyranose) was attained using TiCl4, while SnCl4 promoted their axial-to-equatorial epimerization. The method included application for stereoselective β-d-manno- and β-l-rhamnopyranosyl thiol formation. Complex formation explains
Replacing the Rhamnose‐Xylose Moiety of QS‐21 with Simpler Terminal Disaccharide Units Attenuates Adjuvant Activity in Truncated Saponin Variants
作者:Roberto Fuentes、Ane Ruiz‐de‐Angulo、Nagore Sacristán、Claudio Daniel Navo、Gonzalo Jiménez‐Osés、Juan Anguita、Alberto Fernández‐Tejada
DOI:10.1002/chem.202004705
日期:2021.3.8
not focused on the influence of the linear oligosaccharide domain of QS‐21 in adjuvant activity. Herein, an expeditious 15‐step synthesis of new linear trisaccharide variants of simplified QS‐21‐derived adjuvants is reported, in which the complex terminal xylose‐rhamnose moiety has been replaced with commercially available, simpler lactose and cellobiose disaccharides in a β‐anomeric configuration. In
Electrochemically Mediated S-Glycosylation of 1-Thiosugars with Xanthene Derivatives
作者:Rui-Qi Wang、Qing-Hui Jiang、Hui-Xiang Wang、Xiao-Wei Zhang、Nan Yan
DOI:10.1021/acs.orglett.3c01185
日期:2023.6.16
electrochemical dehydrogenativecross-coupling of benzylic C–H bonds with 1-thiosugars at room temperature is described. The direct S-glycosylation protocol avoids using any oxidant, which provides facile access to various glycosylated xanthene derivatives with up to 91% yield. This current electrooxidative reaction is characterized by high atom economy, high efficiency, mild reaction conditions, being
Photoredox-catalyzed C-glycosylation of peptides with glycosyl bromides
作者:Chen Li、Ziyuan Zhao、Shouyun Yu
DOI:10.1016/j.cclet.2023.109128
日期:2024.6
Glycosylradicals, produced under mild photoredox conditions, show unique utility in the preparation of C-linked glycoconjugates. We herein report the construction of -glycosidic bonds on α,β-dehydroalanine (DHA) of peptides with easily available glycosyl bromides as glycosylradicalprecursorsunder highly anomeric control, leading to -glycosylation modifications of peptides. This method not only