Flavonoids from Alpinia vietnamica, and their cytotoxic, antioxidative, and α‐glucosidase inhibitory activities

Abstract Phytochemical research of the 80% EtOH whole plant extract of Alpinia vietnamica H.Ð. Tran, Luu & Skornick resulted in the isolation and structural elucidation of seven compounds 1–7 , including two flavones quercetin‐3‐ O ‐ α ‐ l ‐rhamnosyl (1→2)‐ α ‐ l ‐rhamnoside ( 1 ) and diosmetin ( 2 ), three flavanones pinocembrin ( 3 ), alpinetin ( 4 ) and 5‐ O ‐methylnaringenin ( 5 ), and two chalcones cardamonin ( 6 ) and helichrysetin ( 7 ). The isolated compounds have shown biological effects at different levels. Two chalcones 6–7 showed cytotoxicity toward four cancer cell lines KB, MCF7, A549, and HepG2, especially compound 7 strongly inhibited the growth of A549 cancerous cells with the IC 50 of 6.81 µ m . Flavone 1 strongly exhibited antioxidative activity to scavenge DPPH radicals with the IC 50 of 51.68 µ m . Flavone 2 and flavanone 4 moderately inhibited enzyme α ‐glucosidase with the IC 50 values of 296.34 – 324.64 µ m .