Rapid Determination of Coumarins in Plants by Capillary Electrophoresis

Abstract

The goal of this study was to optimize the parameters for capillary electrophoresis to separate and determine aesculin, aesculetin, umbelliferone, and dihydrocoumarin in plant materials. A simple and rapid capillary zone electrophoresis method is reported for this separation that required less than nine minutes. A bare fused silica capillary was employed using 20 mM borax in 5% methanol at pH 10.1 as the background electrolyte with an applied voltage of 30 kV at 27°C. Good linearity and reproducibility were obtained with high correlation coefficients. The analytes were determined by molecular absorption at 194 and 206 nm. Coumarins were determined in Aesculus hippocastanum L., Cichorium intybus L., Melilotus officinalis L., and Juniperus communis L. “Pendula.” The concentrations of aesculin and aesculetin were 3.07 and 6.31 mg g⁻¹ in Aesculus hippocastanum. In Cichorium intybus, the aesculetin concentration was 2.42 mg g⁻¹. The dihydrocoumarin concentration was 0.54 mg g⁻¹ in Melilotus officinalis, and the concentration of umbelliferone was 0.58 mg g⁻¹ in Juniperus communis “Pendula.”

Keywords:

• Aesculetin
• Aesculin
• Capillary electrophoresis
• Dihydrocoumarin
• Umbelliferone