Glycosides and thioglycosides based on monosaccharides in reaction with benzaldehyde dimethylacetal or p-methoxybenzaldehyde dimethyl acetal undergo FeCl3-catalyzed (20 mol %) regioselective 4,6-0-arylidenation producing the corresponding acetals in high yields. FeCl3 also mediates acetalation of glycosides and thioglycosides of cellobiose, maltose, and lactose affording the corresponding 4',6'-O-benzylidene acetals, which were isolated after their acetylation in situ with acetic anhydride and pyridine. The combined yields (two steps) of these final products are also high (61-84%). The procedure is applicable to a wide variety of functional groups including -OBn. (C) 2011 Elsevier Ltd. All rights reserved.
作者:Bhavesh Deore、Joseph E. Ocando、Lan D. Pham、Carlos A. Sanhueza
DOI:10.1021/acs.joc.2c00222
日期:2022.5.6
aglycone-derived thiyl radicals (RS•). In contrast, aryl glucosides’ Ep values exhibit excellent correlations with the aryl substituents’ Hammett parameters (σ+) and the ArS• RSEs, evidencing the inherent stability of the reactive radical intermediate as the primary factor controlling aryl glucoside’s electrochemical reactivity. The reactivity differences between alkyl and aryl S-glucosides also extend to the protective
一系列烷基和芳基S-葡糖苷的伏安研究揭示了烷基S-葡糖苷对阳极氧化的反应模式,并发现与芳基衍生物的趋势存在显着差异。烷基S-葡糖苷的氧化电位,本文由方波伏安峰电位( E p )估计,取决于苷元的空间特性。被大体积基团取代的糖苷在电压比带有小糖苷配基的那些的值更正的电压下表现出E p值。在所有分析的烷基系列中观察到的这种关系由E p之间的良好线性相关性证明和各个烷基取代基的 Taft 空间参数 ( ES )。此外,苷元的空间特性作为主要反应性调节剂的作用得到了E p与苷元衍生的硫基自由基 (RS•) 的自由基稳定能 (RSE) 之间较差相关性的支持。相比之下,芳基葡糖苷的E p值与芳基取代基的 Hammett 参数 (σ+) 和 ArS• RSE 表现出极好的相关性,证明了活性自由基中间体的固有稳定性是控制芳基葡糖苷电化学反应性的主要因素。烷基和芳基S-葡糖苷之间的反应性差异也延伸到保护基团对EP
“Mix and match” auto-assembly of glycosyltransferase domains delivers biocatalysts with improved substrate promiscuity
作者:Damien Bretagne、Arnaud Pâris、David Matthews、Laëtitia Fougère、Nastassja Burrini、Gerd K. Wagner、Richard Daniellou、Pierre Lafite
DOI:10.1016/j.jbc.2024.105747
日期:2024.3
in dedicated domains. Here, we have used this selective binding feature to design an engineering process to generate chimeric glycosyltransferases that combine auto-assembled domainsfrom two different GT-B enzymes. Our approach enabled the generation of a stable dimer with broader substrate promiscuity than the parent enzymes that were related to relaxed interactions between domains in the dimeric
ATTEMPTS TO FIND NEW ANTIMALARIALS. VIII.<sup>1</sup> PHENYL β-D-GLUCOTHIOSIDES, DIPHENYL DISULFIDES, PHENYL THIOCYANATES, AND RELATED COMPOUNDS
作者:EDNA M. MONTGOMERY、NELSON K. RICHTMYER、C. S. HUDSON
DOI:10.1021/jo01173a015
日期:1946.5
FeCl3 mediated arylidenation of carbohydrates
作者:Nabamita Basu、Sajal K. Maity、Soumik Roy、Shuvendu Singha、Rina Ghosh
DOI:10.1016/j.carres.2011.01.003
日期:2011.4
Glycosides and thioglycosides based on monosaccharides in reaction with benzaldehyde dimethylacetal or p-methoxybenzaldehyde dimethyl acetal undergo FeCl3-catalyzed (20 mol %) regioselective 4,6-0-arylidenation producing the corresponding acetals in high yields. FeCl3 also mediates acetalation of glycosides and thioglycosides of cellobiose, maltose, and lactose affording the corresponding 4',6'-O-benzylidene acetals, which were isolated after their acetylation in situ with acetic anhydride and pyridine. The combined yields (two steps) of these final products are also high (61-84%). The procedure is applicable to a wide variety of functional groups including -OBn. (C) 2011 Elsevier Ltd. All rights reserved.
Conformational Properties of Aryl <i>S</i>-Glucosides in Solution
作者:Bhavesh Deore、Ryan W. Kwok、Malika Toregeldiyeva、Jesús T. Vázquez、Mateusz Marianski、Carlos A. Sanhueza
DOI:10.1021/acs.joc.3c01156
日期:2023.11.17
The conformational study of saccharides and glycomimetics in solution is critical for a comprehensive understanding of their interactions with biological receptors and enabling the design of optimized glycomimetics. Here, we report a nuclear magnetic resonance (NMR) study centered on the conformational properties of the hydroxymethyl group and glycosidic bond of four series of aryl S-glucosides. We