Antidiabetogenic constituents from several natural medicines

Abstract In the course of our studies on antidiabetogenic and antidiabetic principles of natural medicines and medicinal foodstuffs, we have isolated salacinol and kotalanol with unique thiosugar sulfonium sulfate inner salt structures from the antidiabetic Ayurvedic traditional medicines, Salacia reticulata and S. oblonga . Salacinol and kotalanol showed potent inhibitory activities against intestinal α-glucosidase, and also inhibitory effects of salacinol on the increase in serum glucose levels in maltose- and sucrose-loaded rats were found to be more potent than those of acarbose. In addition, various flavonoids with potent inhibitory activities against rat lens aldose reductase such as quercitrin desmanthin-1 and guaijaverin were isolated from Myrcia multiflora and several natural medicines, and some structural requirements of flavonoids for aldose reductase inhibitory activity were clarified.