850416-39-6Relevant articles and documents
Stereoselective Phenylselenoglycosylation of Glycals Bearing a Fused Carbonate Moiety toward the Synthesis of 2-Deoxy-β-galactosides and β-Mannosides
Li, Zhongjun,Meng, Shuai,Yao, Wang,Zhong, Wenhe
supporting information, (2020/04/09)
A phenylselenoglycosylation reaction of glycal derivatives mediated by diphenyl diselenide and phenyliodine(III) bis(trifluoroacetate) under mild conditions is described. Stereoselective glycosylation has been achieved by installing fused carbonate on those glycals. 3,4-O-Carbonate galactals and 2,3-O-carbonate 2-hydroxyglucals are converted into corresponding glycosides in good yields with excellent β-selectivity, resulting in 2-phenylseleno-2-deoxy-β-galactosides and 2-phenylseleno-β-mannosides which are good precursors of 2-deoxy-β-galactosides and β-mannosides, respectively.
Establishment of Guidelines for the Control of Glycosylation Reactions and Intermediates by Quantitative Assessment of Reactivity
Chang, Chun-Wei,Wu, Chia-Hui,Lin, Mei-Huei,Liao, Pin-Hsuan,Chang, Chun-Chi,Chuang, Hsiao-Han,Lin, Su-Ching,Lam, Sarah,Verma, Ved Prakash,Hsu, Chao-Ping,Wang, Cheng-Chung
, p. 16775 - 16779 (2019/11/03)
Stereocontrolled chemical glycosylation remains a major challenge despite vast efforts reported over many decades and so far still mainly relies on trial and error. Now it is shown that the relative reactivity value (RRV) of thioglycosides is an indicator for revealing stereoselectivities according to four types of acceptors. Mechanistic studies show that the reaction is dominated by two distinct intermediates: glycosyl triflates and glycosyl halides from N-halosuccinimide (NXS)/TfOH. The formation of glycosyl halide is highly correlated with the production of α-glycoside. These findings enable glycosylation reactions to be foreseen by using RRVs as an α/β-selectivity indicator and guidelines and rules to be developed for stereocontrolled glycosylation.
Simple and Practical Real-Time Analysis of Solid-Phase Reactions by Thin-Layer Chromatography
Wu, Chia-Hui,Chen, Chun C.,Lin, Su-Ching,Wang, Cheng-Chung
, p. 1430 - 1436 (2018/05/15)
Solid-phase synthesis is a practical approach for simplifying the time-consuming and routine purification steps in the preparation of numerous naturally occurring molecules; however, studying such reactions is difficult due to the lack of a convenient monitoring method. By using thin-layer chromatography in conjunction with a photolabile linker on a resin, we developed a convenient and simple method for monitoring solid-phase reactions in real time by thin-layer chromatography. This method provides a user-friendly protocol for examining reaction conditions for solid-state syntheses.
Active Site Mapping of Xylan-Deconstructing Enzymes with Arabinoxylan Oligosaccharides Produced by Automated Glycan Assembly
Senf, Deborah,Ruprecht, Colin,de Kruijff, Goswinus H. M.,Simonetti, Sebastián O.,Schuhmacher, Frank,Seeberger, Peter H.,Pfrengle, Fabian
supporting information, p. 3197 - 3205 (2017/03/13)
Xylan-degrading enzymes are crucial for the deconstruction of hemicellulosic biomass, making the hydrolysis products available for various industrial applications such as the production of biofuel. To determine the substrate specificities of these enzymes, we prepared a collection of complex xylan oligosaccharides by automated glycan assembly. Seven differentially protected building blocks provided the basis for the modular assembly of 2-substituted, 3-substituted, and 2-/3-substituted arabino- and glucuronoxylan oligosaccharides. Elongation of the xylan backbone relied on iterative additions of C4-fluorenylmethoxylcarbonyl (Fmoc) protected xylose building blocks to a linker-functionalized resin. Arabinofuranose and glucuronic acid residues have been selectively attached to the backbone using fully orthogonal 2-(methyl)naphthyl (Nap) and 2-(azidomethyl)benzoyl (Azmb) protecting groups at the C2 and C3 hydroxyls of the xylose building blocks. The arabinoxylan oligosaccharides are excellent tools to map the active site of glycosyl hydrolases involved in xylan deconstruction. The substrate specificities of several xylanases and arabinofuranosidases were determined by analyzing the digestion products after incubation of the oligosaccharides with glycosyl hydrolases.
TMSBr-mediated solvent- and work-up-free synthesis of α-2-deoxyglycosides from glycals
Hsu, Mei-Yuan,Liu, Yi-Pei,Lam, Sarah,Lin, Su-Ching,Wang, Cheng-Chung
, p. 1758 - 1764 (2016/10/05)
The thio-additions of glycals were efficiently promoted by a stoichiometric amount of trimethylsilyl bromide (TMSBr) to produce S-2-deoxyglycosides under solvent-free conditions in good to excellent yields. In addition, with triphenylphosphine oxide as an additive, the TMSBr-mediated direct glycosylations of glycals with a large range of alcohols were highly α-selective.
Total synthesis of anticoagulant pentasaccharide fondaparinux
Li, Tiehai,Ye, Hui,Cao, Xuefeng,Wang, Jiajia,Liu, Yonghui,Zhou, Lifei,Liu, Qiang,Wang, Wenjun,Shen, Jie,Zhao, Wei,Wang, Peng
, p. 1071 - 1080 (2014/05/20)
The anticoagulant pentasaccharide fondaparinux was synthesized using an improved and optimized synthetic strategy including a convergent [3+2] coupling approach, orthogonal protecting groups and various glycosyl donors. The new methods of glycosylation were also used for controlling the stereochemical configuration and improving the yield of the glycosylation. In addition, HPLC and NMR methods to monitor the process of total synthesis of fondaparinux were employed. This work provides a comprehensive elaboration for the synthesis and analysis of fondaparinux based on related literature, as well as abundant information for the synthesis of heparin-like oligosaccharides. A matter of protection! The anticoagulant pentasaccharide fondaparinux was synthesized using an improved and optimized synthetic strategy. The process of total synthesis was monitored by HPLC and NMR. This work will contribute to continued improvement of the multistep production of fondaparinux and provide abundant information for the synthesis of heparin-like oligosaccharides.
SYNTHETIC OLIGOSACCHARIDES FOR MORAXELLA VACCINE
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, (2011/11/13)
The present invention provides synthetic Moraxella catarrhalis lipooligosaccharide (LOS)-based oligosaccharides and conjugates containing various M. catarrhalis serotype-specific oligosaccharide antigens or various core M. catarrhalis oligosaccharide structures or motifs corresponding to one or more of the three major serotypes and/or members within a given serotype. The oligosaccharides may be synthesized by a chemical assembly methodology relying on a limited number of monosaccharide and disaccharide building blocks. The invention further provides M. catarrhalis LOS-based immunogenic and immunoprotective compositions and antibodies derived therefrom for diagnosing, treating, and preventing infections caused by M. catarrhalis.
DISACCHARIDE COMPOUNDS
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Page/Page column 6, (2009/06/27)
Disaccharide compounds used as building blocks for making heparin and heparan sulfate oligosaccharides. Also disclosed are methods for making these disaccharide compounds.
Regioselective benzylation of azido-containing monosaccharides
Fan, Qiu-Hua,Li, Qin,Zhang, Li-He,Ye, Xin-Shan
, p. 1217 - 1220 (2007/10/03)
A regioselective benzylation or p-methoxybenzylation of diols in azido-containing monosaccharide derivatives was reported, and the reaction was performed under the conventional reaction conditions (NaH/BnBr in DMF). The hydroxyl functionality adjacent to the azido group was benzylated selectively in good yields. Georg Thieme Verlag Stuttgart.
Synthesis of 48 disaccharide building blocks for the assembly of a heparin and heparan sulfate oligosaccharide library
Lu, Ng-Dai,Shie, Chi-Rung,Kulkarni, Suvarn S.,Pan, Guan-Rong,Lu, Xin-An,Hung, Shang-Cheng
, p. 5995 - 5998 (2007/10/03)
(Chemical Equation Presented) An efficient synthesis of the entire set of suitably protected 48 disaccharide building blocks for the assembly of a heparin and heparan sulfate oligosaccharide library is described here.