GC-MS and q-NMR based chemotaxonomic evaluation of two Leonurus species.

Introduction: The genus Leonurus L. (fam: Lamiaceae) is represented in Uzbekistan by two species, L. panzerioides Popov. and L. turkestanicus V. I. Krecz. & Kuprian, which are used to treat nervous disorders and also as sedative and hypotensive agents.

Objectives: To establish the taxonomic status of Leonurus panzerioides and L. turkestanicus based on their chemical constituents analysed by GC-MS and q-NMR.

Materials And Methods: Quantitative (1) H-NMR (q-NMR) was used to identify and quantify known major components in the methanol extracts of these two species. Additionally, the chemical composition of the essential oils obtained from the aerial parts of these plants were analysed by GC-MS.

Results: The q-NMR analyses of Leonurus panzerioides and L. turkestanicus revealed the presence of 8-acetylharpagide, harpagide, leonurine and stachydrine as major components. Using the GC-MS method, overall 24 and 39 constituents were identified, respectively, from L. panzerioides and L. turkestanicus oils. The major constituents of the essential oil of L. panzerioides were eugenol (30.9%) and p-vinyl guaiacol (15.8%), whereas thymol (40.1%) and octen-3-ol (13.1%) were the principal compounds in the essential oil of L. turkestanicus.

Conclusion: The major components in Leonurus panzerioides and L. turkestanicus as identified by the GC-MS and q-NMR analyses, were similar to those present in other Leonurus species and thus provided chemotaxonomic evidence for the placement of these species under the genus Leonurus. Copyright © 2016 John Wiley & Sons, Ltd.