Synthesis of lipophilic 1-deoxygalactonojirimycin derivatives as D-galactosidase inhibitors

N-Alkylation at the ring nitrogen of the D-galactosidase inhibitor 1-deoxygalactonojirimycin with a functionalised C-6 alkyl chain followed by modification with different aromatic substituents provided lipophilic 1-deoxygalactonojirimycin derivatives which exhibit inhibitory properties against beta-glycosidases from E. coli and Agrobacterium sp. as well as green coffee bean alpha-galactosidase. In preliminary studies, these compounds also showed potential as chemical chaperones for GM1-gangliosidosis related beta-galactosidase mutants.