Identification of flavonoids and flavonoid rhamnosides from Rhododendron mucronulatum for. albiflorum and their inhibitory activities against aldose reductase

► Six flavonoids were isolated from R. mucronulatum for. albiflorum. ► All flavonoids exhibited high aldose reductase inhibitory activities. ► The major flavonoids are quercitrin and myricitrin by HPLC analysis.