A Route to 1-Deoxynojirimycin and 1-Deoxymannojirimycin Derivatives with Quaternary Centers Adjacent to the Ring Nitrogen from Methyl α- d -Mannopyranoside: A Route to 1-Deoxynojirimycin and 1-Deoxymannojirimycin Derivatives with Quaternary Centers Adjacent to the Ring Nitrogen from Methyl α-d-Mannopyranos

Evaluation of nonnatural L-iminosugar C,C-glycosides, a new class of C-branched iminosugars, as glycosidase inhibitors

Capitalizing on a previously developed Staudinger/azaWittig/Grignard (SAWG)-ring contraction sequence that furnished protected six-membered L-iminosugar C,C-glycosides bearing an allyl group and various substituents at the pseudoanomeric position, the synthesis and glycosidase inhibition of a small library of six- and seven-membered L-iminosugar C,C-glycosides is reported. Their hydrogenolysis or cyclization by RCM followed by deprotection afforded eleven L-iminosugars including spirocyclic derivatives. All compounds adopt a 1C4 conformation in solution according to NMR data. Compared to previously reported branched L-iminosugars, the L-iminosugar C,C-glycosides reported herein were less potent glycosidase inhibitors. However, some of these compounds showed micromolar inhibition of human lysosome β-glucocerebrosidase suggesting that such iminosugars could be useful to access potent CGase inhibitors by adjusting the structure/length of the pseudoanomeric substituents.

Stereoselective Access to Iminosugar C,C-Glycosides from 6-Azidoketopyranoses

We report the synthesis of iminosugar C,C-glycosides starting from 6-azidoketopyranoses. Their Staudinger-azaWittig-mediated cyclization provided bicyclic N,O-acetals, which were stereoselectively opened with AllMgBr to afford β-hydroxyazepanes with a quaternary carbon α to the nitrogen. Their ring contraction via a β-aminoalcohol rearrangement produced the six-membered l-iminosugars with two functional handles at the pseudoanomeric position. Inversion of the free OH at the azepane level furnished the d-iminosugars.

An overview of therapeutic potential of N-alkylated 1-deoxynojirimycin congeners

Polyhydroxylated alkaloids display a wide range of biological activities, suggesting their use in the treatment of various diseases. Their most famous representative, 1-deoxynojirimycin (DNJ), is a natural product that shows α- and β-glucosidase inhibition. This molecule has been since converted into two clinically approved drugs i.e., Zavesca® and Glyset®, targeting type I Gaucher's disease and type II diabetes mellitus, respectively. This review examines the therapeutic potential of important DNJ congeners reported in last decade and presents concise mechanism of glycosidase inhibition. A brief overview of substituents conjugation's impact on DNJ scaffold (including N-alkylated DNJ derivatives, mono-valent, di-valent and multivalent DNJ congeners, N-[5-(adamantan-1-yl-methoxy)-pentyl]-1-deoxynojirimycin (AMP-DNM) look alike DNJ based lipophilic derivatives, AMP-DNM based neoglycoconjugates, DNJ click derivatives with varying carboxylic acids and aromatic moieties, conjugates of DNJ and glucose, and N-bridged DNJ analogues) towards various enzymes such as α/β glucosidase, porcine trehalase, as F508del-CFTR correctors, α-mannosidase, human placental β-glucocerebrosidase, N370S β-GCase, α-amylase and insect trehalase as potent and selective inhibitors have been discussed with potential bioactivities, which can provide inspiration for future studies.