Design, synthesis and in vitro study of densely functionalized oxindoles as potent α-glucosidase inhibitors.

•Novel oxindoles as potent α-glucosidase inhibitors.•Designed via scaffold hopping and bioisosteric modification of known inhibitors.•Synthesized by using combinatorial synthesis via a three component reaction.•In vitro screening against yeast α-glucosidase indicated substantial inhibition.•Most active compound is a competitive inhibitor.