Determination of phytomarkers in pharmaceutical preparations of Hemidesmus indicus roots by micellar electrokinetic chromatography and high-performance liquid chromatography-mass spectrometry

Micellar electrokinetic chromatography was applied to the determination of the major phytomarkers, namely 2-hydroxy-4-methoxybenzaldehyde, 2-hydroxy-4-methoxybenzoic acid, and 3-hydroxy-4-methoxybenzaldehyde, of Hemidesmus indicus root, an Indian medicinal plant. H. indicus bioactive preparations were analyzed by reverse flow micellar electrokinetic chromatography (MEKC) using sodiumtaurodeoxycholate as the surfactant. A pH 2.5 phosphate buffer (50mM) was supplemented with 65mM of sodium taurodeoxycholate to produce the MEKC pseudostationary phase; because of the suppression of the electroosmotic flow, the migration of the partitioned analytes was toward the capillary anodic end. The use of a short fused-silica capillary (8.5 cm effective length; 50 µm i.d.) allowed the separation of phytomarkers, including vanillin and salicylaldehyde (reported as additional metabolites of H. indicus roots), in less than 8 min. The method showed good validation parameters and was applied to the analysis of methanol extracts and a root decoction of H. indicus, a promising botanical drug. The obtained results were compared to those from an independent high-performance liquid chromatography–mass spectrometry method. The 2-Hydroxy-4-methoxybenzaldehyde, 2-hydroxy-4-methoxybenzoic acid, and 3-hydroxy 4-methoxybenzaldehyde were found in all samples confirming their roles as phytomarkers. The absence of vanillin and salicylaldehyde suggested that these latter compounds should not be regarded as characteristic components of the bioactive preparations from the plant roots.