Acetonides are the only protecting groups used in the syntheses of isoDAB from d-ribose and of isoLAB from d-tagatose. isoDAB is a potent and highly specific competitive α-glucosidase inhibitor (for rice α-glucosidase, Ki = 4 μM for isoDAB compared to K i 14 μM for DAB). isoDAB is not an - whereas DAB is a potent - inhibitor of glycogen phosphorylase. This is the first example of any potent inhibition of glycosidases by a carbon-branched iminosugar pyrrolidine. Although isoLAB shows no inhibition of any glycosidase, preliminary experiments suggest that isoLAB partially rescues the defective F508del-CFTR function and so may have a role in the study of cystic fibrosis. © 2010 Elsevier Ltd. All rights reserved.
