α-Glucosidase Inhibitory Activity of Kaempferol-3- O -rutinoside

Quercetin, kaempferol and to a lesser extent rutin have been reported to have antidiabetic activities when assessed by various assay models including in vitro alpha-glucosidase inhibition studies. A related structural analogue, kaempferol-3-O-rutinoside (KR) however has not yet been studied for such biological effects. It was found that KR is a potent inhibitor of alpha-glucosidase in vitro with over 8-times more activity than the reference antidiabetic drug, acarbose. Furthermore, KR displayed a synergistic effect with a less potent flavonoid aglycones, kaempferol and quercetin. The structure-activity profile of these drugs and implications of drug combinations are discussed.