Synthesis and l-fucosidase inhibitory activity of a new series of cyclic sugar imines—in situ formation and assay of their saturated counterparts

The synthesis of a series of aryl-substituted cyclic sugar imines was performed via a tandem nucleophilic addition/substitution reaction. The so-obtained ketimines displayed fucosidase inhibitory activities (IC50 = 46–556 μM). Their reduced counterparts were prepared and assayed after addition of sodium borohydride to the enzymatic assay stock solution. The pyrrolidines strongly inhibit fucosidase (IC50 = 0.65–150 μM).