Thioimidoyl furanosides as first inhibitors of the α-l-arabinofuranosidase AbfD3
摘要:
Two sets of five thioimidoyl alpha-L-arabino- and beta-D-galactofuranosides were designed, synthesized and subjected to docking studies to evaluate their ability to be recognized by the active site of the alpha-L-arabinofuranosidase AbfD3. Further in vitro assays showed that the targeted furanosides are the first potent inhibitors of this furanosyl hydrolase and that the most efficient one, the thiazolyl alpha-L-arabinofuranoside 1, is a competitive inhibitor having a K-I of 1.4 mu M. (c) 2006 Elsevier Ltd. All rights reserved.
renewable and eco-friendly partner of the glycosylation reaction allowed the one step synthesis of the arabinofuranosylcluster 4 in 38% yield. Our mutated biocatalyst was able to perform coupling to a multivalent bulky substituent with 80% yield on each arm and pave the way for the further development of enzymatic means of ligation of carbohydrates onto organic scaffolds.
Thioglycosidic bonds are of utmost importance in biomolecules as their incorporation led to more stable glycomimetics with potential drug activities. Until now only chemical methods were available for their incorporation into glycofuranosyl conjugates. Herein, we wish to describe the use of the first furanothioglycoligase for the preparation of a great variety of thioaryl derivatives with moderate to excellent yields. Of great interest, a stable 1-thioimidoyl arabinofuranose, classically used in chemical glycosylation, was able to efficiently act as a donor through an original enzymatic remote activation mechanism. Study of the chemical structure as well as the nucleophilicity of the thiol allowed us to optimize this biocatalyzed process. As a consequence, this mutated enzyme constitutes an original, mild and eco-friendly method of thioligation.
Direct activation of unprotected thioimidoyl furanosides yielded in only one step and few minutes a panel of rare uridine 5'-diphosphofuranoses. Diastereoselectivity of the reaction was tightly connected with reaction time, temperature, and nature of the furanosyl donor. This approach was totally selective since no ring expansion from the initial five-membered ring to the more stable pyranose form was observed.
Diversion of a thioglycoligase for the synthesis of 1-<i>O</i>-acyl arabinofuranoses