Determining Substrate Specificities of β1,4-Endogalactanases Using Plant Arabinogalactan Oligosaccharides Synthesized by Automated Glycan Assembly
作者:Max P. Bartetzko、Frank Schuhmacher、Peter H. Seeberger、Fabian Pfrengle
DOI:10.1021/acs.joc.6b02745
日期:2017.2.3
glycosyl hydrolases. We report the automatedglycanassembly of oligosaccharides related to the arabinogalactan side chains of pectin as novel biochemical tools to determine the substratespecificities of endogalactanases. Analysis of the digestion products revealed different requirements for the lengths and arabinose substitution pattern of the oligosaccharides to be recognized and hydrolyzed by the
cassettes, which were utilized towards syndecan-3 glycopeptides. The glycopeptides presented many obstacles for post-glycosylation manipulation, peptide elongation, and deprotection. Following screening of multiple synthetic sequences, a successful strategy was finally established by constructing partially deprotected single glycan chain containing glycopeptides first, followed by coupling of the glycan-bearing
The first total synthesis of a highly branched heptadecasaccharide moiety of the native bioactive galectin-3-targeting polysaccharide from Carthamus tinctorius has been accomplished via a photo-assisted convergent [6+4+7] one-pot coupling strategy. This work demonstrates a representative example to explore potential active domains of the polysaccharide for structure–activity relationship studies, thereby
作者:Zhiyuan Zhang、Ian R. Ollmann、Xin-Shan Ye、Ralf Wischnat、Timor Baasov、Chi-Huey Wong
DOI:10.1021/ja982232s
日期:1999.2.1
In an effort to develop a broadly applicable approach to the facile one-pot synthesis of oligosaccharides, the reactivity of a number of p-methylphenyl thioglycoside (STol) donors which are either fully protected or have one hydroxyl group exposed has been quantitatively determined by HPLC. We have characterized and quantified the influence on reactivity of the structural effects of different monosaccharide cores and different protecting groups on each glycoside donor. In addition, we have established a correlation between glycosyl donor reactivity and the chemical shift of the anomeric proton by H-1 NMR. Using the reactivity data, we have created a database of thioglycosides as glycosyl donors and demonstrated its utility in the easy and rapid one-pot assembly of various linear and branched oligosaccharide structures. In addition, we have developed the first computer program, OptiMer, for use as a database search tool and guide for the selection of building blocks for the one-pot assembly of a desired oligosaccharide or a library of individual oligosaccharides.