Alpha-glucosidase and tyrosinase inhibiton of polyphenols isolated from Potentilla speciosa var. speciosa: In vitro and in silico perspectives

•A number of extracts and isolates of Potentilla speciosa var. speciosa were identified.•The extracts and isolates were tested for α-glucosidase and tyrosinase inhibition.•The butanol extract and Cinnamtannin D1 proved highly potent α-glucosidase inhibitors.•It is the first report of Cinnamtannin D1 occurrence in genus Potentilla.•Molecular docking suggested allosteric binding for Cinnamtannin D1.