Antioxidative Activity Estimation of Methanol Extracts of Crude Drugs by Electrochemical Detection-High Performance Liquid Chromatography (ECD-HPLC) and Correlation with 1, 1-Diphenyl-2-picrylhydrasyl (DPPH) Radical Scavenging Activities

Abstract

As a method for estimation of the antioxidative activity of methanol extracts of crude drugs, cyclic voltammograms (CV), 1, 1-diphenyl-2-picrylhydrasyl (DPPH) radical scavenging activities, and electrochemical detection (ECD)-HPLC were investigated. From a comparison of results, crude drugs which show oxidative peaks in the low potential region in CV, had strong and rapid radical scavenging activities. A correlation (r²=0.76) between DPPH radical scavenging ability and total peak area detected by ECD-HPLC, was obtained. The ECD-HPLC method is therefore useful for evaluation of antioxidative activities, as well as a separational analysis method for antioxidative ingredients.