α-glucosidase inhibitors from commelina communis

A methanolic extract of Commelina communis showed potent inhibitory activity against α-glucosidase. One pyrrolidine alkaloid, 2,5- dihydroxymethyl-3,4-dihydroxypyrrolidine (DMDP, 1) and four piperidine alkaloids, 1-deoxymannojirimycin (2), 1-deoxynojirimycin (3), α- homonojirimycin (4) and 7-O-β-D-glucopyranosyl α-homonojirimycin (5) were isolated by bioassay-directed fractionation and separation. These compounds have been identified for the first time from Commelina communis, supporting the pharmacological basis of this plant that has been used as a traditional herbal medicine for the treatment of diabetes.ope