This study was performed to investigate the possible utilization of Hemerocallis fulva (H. fulva) leaves as either functional food or natural antioxidants. To determine the optimum extraction solvent, the dried H. fulva was extracted with 7 solvents, and yield, total flavonoid content and 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity of each extract were compared. Among the extracts, 80% ethanol extract showed the highest yield, total flavonoid content and DPPH scavenging activity. The 80% ethanol extract was further fractionated subsequently by n-hexane, chloroform, ethyl acetate, n-butanol and water. Among five fractions from 80% ethanol extract, the ethyl acetate fraction showed the highest total flavonoid content (322.99 mg Que/g) among five fractions, and also exhibited an excellent DPPH scavenging activity (89.09∼93.79 at 100∼500 Ռg/ml). Metal-ion (10⁻³ M FeCl₃) chelating effect of the ethyl acetate fraction at the concentration of 100 Ռg/ml showed 75.46%. The present study indicated that the ethyl acetate fraction exerted the highest total flavonoid content and the strongest antioxidative activity, suggesting that ethyl acetate fraction contains the bioactive compounds with antioxidative activity. (Cancer Prev Res 18, 74-79, 2013)

Keywords: Hemerocallis fulva, Total flavonoid content, DPPH scavanging activity, Metal chelating effect