Flavonoid Compounds from Krokot Herb (Lygodium microphyllum) and their Antioxidant Activity against DPPH

Abstract

Six flavonoid compounds, kaempferol (1), quercetin (2), acacetin (3), quercetin-3-O-?-D-glucopyranoside (4), kaempferol-3-O-?-D-glucopyranoside (5), and isorhamnetin-3-O-?-D-glucopyranoside (6), were isolated from the methanol extract of the Lygodium microphyllum herb. The chemical structures of compounds 1-6 were identified on the basis of spectroscopic evidence and comparison with previously reported spectral data. Compounds 1-6 were isolated for first time from this plant. Their antioxidant activity against DPPH (2,2- Diphenyl-1-picrylhydrazyl) was evaluated. Among the compounds, quercetin (2) showed high antioxidant activity with IC50 values of 6.94 ± 0.03 ?g/mL.