Synthesis of a salacinol analogue and its alpha-glucosidase inhibitory activity.

To investigate more efficient synthetic method of the nitrogen analogue 4 of salacinol (1) for searching new antidiabetic agents.The synthesis of the key intermediate 2, 4-O-isopropylidene-L-erythritol 1,3-cyclic sulfate (2a) was accomplished by modification of reports from D-glucose via seven steps in much more less expensive. Using this method, an efficient synthesis of 4 was carried out. The glycosidase inhibitory activity of 4 was tested for the intestinal alpha-glucosidase in vitro and compared with that of salacinol.A nitrogen analogue 4 of salacinol (1) was synthesized by the coupling reaction between the cyclic sulfate 2a and an azasugar 3b.Substitution of the sulfur atom in 1 with a nitrogen reduced the activity considerably.