Chromatographic Profiles of the main Secondary Metabolites in the Monarda fistulosa L. Aerial Part

Abstract

Two different methods of chromatographic analysis have been used in this study for the phytochemical evaluation of main secondary metabolites in the aerial part of bee balm (Monarda fistulosa L.) as the non-officinal medicinal plant of the Lamiaceae Martinov family. The high performance thin layer chromatography (HPTLC) fingerprinting method was developed for the qualitative analyses of phenolic and non-polar compounds in the bee balm herb after its maceration in the solvents of different polarity. Such polyphenols as rosmarinic, caffeic and chlorogenic acids were authentically identified in the methanol extract of herb using HPTLC. Aromatic monoterpenoid thymol was identified by the HPTLC method in the extracts obtained with non-polar solvents (toluene, methylene chloride, and chloroform). 38 volatile compounds were determined in the methylene chloride extract of M. fistulosa herb by gas chromatography mass spectrometry (GC/MS); it was taken into account only components with the content more than 0.2 %. The GC/MS analysis showed that thymol (23.73 %), followed by carvacrol (10.09 %), p-cymene (9.74 %), and thymoquinone (8.52 %) were the major constituent of methylene chloride extract. Used chromatographic techniques may be recommended for the reliable phytochemical authentication of the M. fistulosa herb.