Determination of Shikonin and Rosmarinic Acid in Echium vulgare L. and Echium russicum J.F. Gmel. by Capillary Electrophoresis

Abstract

A simple and rapid capillary zone electrophoresis (CZE) procedure for determination of shikonin and rosmarinic acid in roots of Echium vulgare L. and Echium russicum J.F. Gmel. is described. The separation was achieved in less than 4 min. The analysis was performed in fused silica capillary (i.d. 75 µm, 48.5 cm total length) using 50 mM borate, at pH 9.5 as the run buffer with applied voltage of 30 kV and constant temperature (27 °C). The method ensures good linearity and repeatability with high correlation coefficients (0.994 and 0.998 for shikonin and rosmarinic acid, respectively). The compounds were detected by UV absorption at 218 (shikonin) and 202 nm (rosmarinic acid). The limits of detection (LOD) for shikonin and rosmarinic acid were 0.603 ppm and 0.270 ppm, respectively. The method was used for estimation of both components in Echium plants. We found out that the content of shikonin and rosmarinic acid were 4.4–4.8 mg/kg air-dry material and 20.0–54.2 mg/kg air-dry material, respectively, in the Echium species analyzed.