Phytochemical and Biological Traits of Endemic Betonica bulgarica (Lamiaceae)

Betonica bulgarica is an endemic species distributed in Bulgaria. The chemical composition of the essential oil analysed by GC&ndash
MS (Gas chromatography&ndash
mass spectrometry) and the content of trace elements analysed by ICP&ndash
MS (Inductively coupled plasma mass spectrometry) were determined. Additionally, a study on the types and distribution of trichomes was done using a microscope with a camera. The essential oil was characterized using a high concentration of sesquiterpene hydrocarbons, whose major compounds are &beta
caryophyllene (17.4%), germacrene D (9.9%), and &beta
bourbonene (6.7%). The contents of manganese (177.2 &micro
g/g) and strontium (156.8 &micro
g/g) were highest among the investigated micronutrients. Two types of trichomes were identified on the adaxial and abaxial epidermises of the leaves of B. bulgarica&mdash
covering and glandular. Peltate stacked glandular trichomes with a four-celled head of type B were observed on the leaf surface.