Applications of Shoda's reagent (DMC) and analogues for activation of the anomeric centre of unprotected carbohydrates
作者:Antony J. Fairbanks
DOI:10.1016/j.carres.2020.108197
日期:2021.1
its derivatives are useful for numerous synthetic transformations in which the anomeric centre of unprotected reducing sugars is selectively activated in aqueous solution. As such unprotected sugars can undergo anomeric substitution with a range of added nucleophiles, providing highly efficient routes to a range of glycosides and glycoconjugates without the need for traditional protectinggroup manipulations
Aryl 1-thioglycosides have directly been synthesized in good yields from the corresponding unprotected sugars and thiols without protection of the hydroxy groups by using 2-chloro-1,3-dimethylimidazolinium chloride (DMC) as dehydrative condensing agent. The reaction proceeded in a mixed solvent of water and acetonitrile under mild reaction conditions, leading to the predominant formation of β-anomers.
Novel triple mutant of an extremophilic glycosyl hydrolase enables the rapid synthesis of thioglycosides
作者:Lauriane Pillet、David Lim、Nourah Almulhim、Ana I. Benítez-Mateos、Francesca Paradisi
DOI:10.1039/d2cc04660a
日期:——
order to expand the toolbox of enzymes available for thioglycosidesynthesis, we describe here the first example of an extremophilic glycosyl hydrolase from Halothermothrix orenii (HorGH1) engineered towards thioglycosynthase activity with a novel combination of mutations. Using the triple mutant, HorGH1 M299R/E166A/E354G, a range of thioglycosides from glycosyl fluoride donors and aromatic thiols could
为了扩展可用于硫糖苷合成的酶的工具箱,我们在此描述了来自Halothermothrix orenii ( Hor GH1) 的极端糖基水解酶的第一个例子,该酶被改造为具有新的突变组合的硫糖合酶活性。使用三重突变体Hor GH1 M299R/E166A/E354G,可以合成一系列来自糖基氟化物供体和芳香族硫醇的硫苷,具有出色的立体选择性和良好的转化率 (61–93%)。
A New Approach to the Synthesis of Benzothiazole, Benzoxazole, and Pyridine Nucleosides as Potential Antitumor Agents
作者:Ahmed I. Khodair、Najim A. Al-Masoudi、Jean-Pierre Gesson
DOI:10.1081/ncn-120026407
日期:2003.11
A modified nitrogen and sulfur glycosylation reaction involving benzothiazole benzoxazole and pyridine nucleoside bases with furanose and pyranose sugars are described. Conformational analysis has been studied by homo- and hetero-nuclear two-dimensional NMR methods (2D DFQ-COSY, HMQC and HMBC). The N and S sites of glycosylation were determined from the H-1, C-13 hetero-nuclear multiple-quantum coherence (HMQC) experiments. All the deprotected nucleosides were tested for their potential antitumor activity.
Chemistry of the glycosidic linkage. Exceptionally fast and efficient formation of glycosides by remote activation