One-Pot Synthesis of Unprotected Anomeric Glycosyl Thiols in Water for Glycan Ligation Reactions with Highly Functionalized Sugars
作者:Sebastian Köhling、Matthias P. Exner、Saba Nojoumi、Jürgen Schiller、Nediljko Budisa、Jörg Rademann
DOI:10.1002/anie.201607228
日期:2016.12.12
Chemical synthesis of oligosaccharide conjugates is essential for studying the functional relevance of carbohydrates, and this task would be facilitated considerably if reliable methods for the anomeric ligation of unprotected sugars in water were available. Here, a method for the preparation of anomeric glycosyl thiols from complex unprotected mono‐, di‐, and oligosaccharides is presented. By exploiting
Peracetylated laminaribiose: preparation by specific degradation of curdlan and its chemical conversion into N-acetylhyalobiuronic acid
作者:Lai-Xi Wang、Nobuo Sakairi、Hiroyoshi Kuzuhara
DOI:10.1016/0008-6215(91)89048-k
日期:1991.10
beta-Laminaribiose octaacetate (2b) was prepared in greater than 50% yield from the microbial polysaccharide curdlan by specificdegradation with a yeast cell-wall lytic enzyme preparation, Kitalase,and subsequent acetylation. Acetolysis of curdlan also gave alpha-laminaribiose octaacetate (2a) in 27% yield. The usefulness of these peracetates 2a and 2b as starting materials for organic synthesis was
(HAses) purified from bovine testes and Streptomyces were investigated in vitro. It was found that (i) GL inhibits the activity of HAse (p55) from bovine testes in a dose-dependent manner, but does not affect HAse fromStreptomyces; (ii) GL was the most effective of the compounds tested on bovine testis HAse activity (50% inhibition with approx. 3 microM GL); and (iii) glycyrrhetinic acid (GA), a derivative
of sulfates. Affinities strongly depend on the anomeric modification of the GAG. Highest binding affinities are effected by anomeric functionalization with large fluorophores and by GAG dimerization. Our experimental and theoretical results suggest that the diversity of GAG binding sites and modes is responsible for the observed high affinities and other binding features. The presented new insights into