Convenient synthesis and evaluation of enzyme inhibitory activity of several N-Alkyl-, N-Phenylalkyl, and cyclic isourea derivatives of 5a-Carba-α- -fucopyranosylamine

Convenient synthesis and chemical modification of the potent α- -fucosidase inhibitor, 5a-carba-α- -fucopyranosylamine (1), are described. Among seven N-substituted and three cyclic isourea derivatives newly prepared, the N-octyl derivative was found to be the strongest inhibitor of α- -fucosidase (bovine kidney) more potent (Ki=0.016 μM) than deoxyfuconojirimycin (Ki=0.031 μM) with p-nitrophenyl-α- -fucopyranoside as the substrate.