Variability of the component composition of Vitexagnus-castus L. essential oil

Vitex agnus-castus L. (chaste tree) is a valuable medicinal and essential oil plant (Lamiaceae), cultivated as an ornamental and medicinal plant in subtropical regions around the world. Under the natural conditions of the Crimea, chaste tree grows singly or in groups at the mouths of beams on the coast, is listed in Red Book of the Crimea with environmental status - a rare species. In the collections of the Nikita Botanical Gardens there are three forms of Vitex introduced from different places of growth and differing in morphological and biological characteristics. Vitex leaves contain essential oil, characterized by antimicrobial, antifungal, anti-inflammatory effects, as well as high antibacterial activity. The aim of our research was to investigate the component composition of the essential oil of the leaves of these forms of chaste tree to determine their chemotypes. Material and Methods. The mass fraction of essential oil was determined during the budding phase of plants (early July) by hydrodistillation on Ginsberg apparatuses. The composition of the volatiles was determined using a hardware-software complex based on a Chromatek-Crystal 5000.2 chromatograph. Results. As a result of the studies, it was found that the form with a light purple color of the corolla, introduced from the natural flora of the Crimea, in the conditions of culture is characterized as long-growing with a high content of essential oil in the leaves (0.79% of the absolute dry weight) with a sharp pepper-clove spicy odor due to the high proportion of sesquiterpenes (β-caryophylllene, β-farnesene, bicycloher-macrene), the amount of which is 43%. The foreign forms of chaste tree with a pink and purple color of the corolla are distinguished by an early onset of flowering, a lower content of essential oil (0.47-0.6%) with a strong balsamic peppermint smell and a high content of 1,8-cineole in it (35, 2-37.7%). Conclusions. A comparative analysis of the obtained and existing literature data indicates the presence of several chemotypes of essential oil in chaste tree: 1,8-cineole and pinene. The essential oil of the studied forms of chaste tree from the natural habitats of the Crimea belongs to the cineole-farnesene subtype, and foreign introduced ones - to the cineole-sabinene.

Vitex agnus-castus, essential oil component composition, 1, 8-cineole, α- and β-pinene, sesquiterpenes, chemotype