β- -Glycosylamidines: potent, selective, and easily accessible β-glycosidase inhibitors

β- -Glycosylamidines, in which a glycon is connected via an N-glycoside linkage with a substituted amidine (aglycon), were synthesized in two steps from the corresponding sugars and served as stable and potent β-glycosidase inhibitors with high selectivity according to the glycon- and α, β-specificities of the enzymes.