Synthesis of Branched Dithiotrisaccharides via Ring-Opening Reaction of Sugar Thiiranes
作者:Evangelina Repetto、Verónica E. Manzano、María Laura Uhrig、Oscar Varela
DOI:10.1021/jo2018685
日期:2012.1.6
(3→3)-disulfide 19, which resulted from the oxidative dimerization of 17. However, the S-acetyl derivative of 17 could be obtained in good yield (62%) by LiAlH4 reduction of the crude mixture 17–19, followed by acetylation. The same sequence of reactions starting from 14 and the 1-thiolate of Galp afforded the per-O,S-acetyl derivative of Galp-β-S-(1→4)-3,4-dithio-α-d-Glcp-O-iPr (23), which was selectively
Synthesis of the (1→6)-linked thiodisaccharide of galactofuranose: Inhibitory activity against a β-galactofuranosidase
作者:Evangelina Repetto、Carla Marino、Oscar Varela
DOI:10.1016/j.bmc.2013.02.057
日期:2013.6
A new (1 -> 6)-linked thiodisaccharide formed by two galactofuranosyl units has been synthesized. Methyl (methyl alpha,beta-D-galactofuranosid) uronate was employed as the starting compound, which was per-O-silylated with TBSCl and reduced with LiAlH4 to afford methyl 2,3,5-tri-O-tert-butyldimethylsilyl-beta-D-galactofuranoside (2 beta) as a key precursor for the preparation of methyl per-O-tert-butyldimethylsilyl-6-thio-beta-D-galactofuranoside (12). The free thiol group of 12 was glycosylated and the product O-deprotected to afford the target beta-D-Galf-S-(1 -> 6)-beta-D-Galf-OMe (14). The conformations of this thiodisaccharide were preliminarily studied using combined theoretical calculations and NMR data. Furthermore, the glycomimetic 14 showed to be a competitive inhibitor of the beta-galactofuranosidase from Penicillum fellutanum (K-i = 3.62 mM). (C) 2013 Elsevier Ltd. All rights reserved.