Determination of camptothecins in DMSO extracts of Nothapodytes foetida by direct injection capillary electrophoresis

A rapid capillary electrophoresis procedure was developed for determining the anti‐cancer components, camptothecins, in Nothapodytes foetida. The hydrophobic compound was extracted from plant tissue (ca. 1 mL of DMSO for 100 mg of dried plant tissue) with a water‐miscible organic solvent, DMSO, at elevated temperature (60°C). The extract was directly injected into the separation capillary (untreated fused silica, 34 cm in length, 75 µm i.d.) and analysed in MEKC mode (369 nm). Within 5 min of migration, camptothecins were successfully separated and quantified by adding organic modifiers to the running buffer (20% DMSO, 90 m m SDS in 10 m m borate buffer, pH 8.60). The linear dynamic range for camptothecin was from 5 to 400 µg/mL. This method was proven to be very suitable for monitoring the amount of camptothecins during the cultivation of the medicinal plant. Copyright © 2007 John Wiley & Sons, Ltd.