earticle

영어

The antioxidant activity of Rucommia ulmoides Oliver's bark extracts was qualitatively and quantitatively evaluated. The extraction yields increased with increasing the extraction
temperature, and an optimal extraction temperature is 78℃. Major antioxidant components of the extracts are 5-dihydroxybenzoic acid, caffeic acid, and tannin. IC50(1,140mg L-1 at 100mM ,2-diphenyl-lpicrylhydrazyl(DPPH)), maximum radical scavenging ability(24∼26μg-DPPH mg-extract-1), and reaction constant of the extracts are have similar values, irrespective of extraction temperature. As a new analytical method for the radical scavenging ability of antioxidant, the kinetic analysis of DPPH scavenging were suggested. The DPPH scavenging by antioxidants was expressed with the first order reaction, and the rate constants of DPPH scavenging reaction by the extracts and butylated hydroxytoluene (BHT) were 1.18∼1.28×10-5 and 3.02× 10-5 mg-antioxidant-1 min-1 L, respectively.
In conclusion, instead of IC50, the kinetic analysis presented in this study can be applied to assess the radical scavenging ability of antioxidant.