Essential oil composition of Stachys anisochila

Abstract

Continuing our research on the composition and chemical polymorphism of the essential oil of the genus Stachys L., species from Serbia, we now report the results on the volatile oil of S. anisochila. The results of the essential oil analysis of S. anisochila are presented in Table 1. GC and GC-MS analysis showed 76 compounds. The main compounds were: -pinene (7.6%), -pinene (5.28%), -copaene (6.25%), and -caryophyllene (4.48%). S. anisochila essential oil contains monoterpenes (34.02%), sesquiterpenes (23.8%), and diterpenes (7.5%). This species, together with S. menthifolia and S. plumosa, belongs to subgenus Stachys, sectio Swainsonniana subsectio Decumbentes [25]. Their essentail oil composition showed that there are remarkable differences in the major constituents. The essential oil of S. plumosa is characterized by high contents of monoterpenes (70%), comprising both - and -pinenes as S. anisochila. On the other hand, the essential oil of S. menthifolia has a very high content of diterpenes (38%). The main components of S. menthifolia were abietatriene (12.99%), kaurene (12.35%), valeranone (5%), and -cadinol (4.2%). The main components of S. plumosa were -pinene (35.84%), -pinene (31.74%), -bourbonene (8%), limonene (3.62%), and abietatriene (3.47%). In our previous work, the essential oil compositions of ten Stachys species from Serbia were analyzed. The sesquiterpenes dominated in all the investigated samples of essential oils of Stachys species. Monoterpenes were present as well, but in variable amounts. The essential oils of species belonging to the subgenus Betonica (S. officinalis and S. scardica) contain a large proportion of sequiterpenes (70–80%), but the content of monoterpenes is exceptionally low, whereas diterpene compounds are completely lacking. These results may be useful in chemotaxonomy, but it is necessary to analyze more species of these genera and more populations of each species from different localities, including analyses of other secondary metabolites (e.g., flavonoids). The essential oils of Stachys species are a perspective source of interesting natural compounds. Investigation of the biological activity of essential oils of Stachys species showed antibacterial, antifungal, and antioxidative activity, which can be related to the essential oil composition. Plant Material and Isolation Procedure. The aerial parts of S. anisochila were collected at the flowering stage in