Essential Oil Quantity and Quality of Different Plant Organs from Perovskia abrotanoides Karel in Natural Habitat of North Khorasan Province

Background and Objectives Chemical variability among populations according to their geographical and bio climatic distribution imposes that conservation strategies of populations should be made appropriately, taking into account these factors. Perovskia, with the common Persian name of "Brazemble", a small genus from Lamiaceae family, is distributed in various regions of Asia, as Iran, Afghanistan and Pakistan. The genus is represented in Iran by only three species as P. abrotanoides, P. atriplicifolia and P. artemisoides. The plant is an aromatic shrub which mainly grow in mountains at an altitude of 2200 to 4200 m from Northeastern across center to Southeastern of Iran. All parts of the plant are aromatic, but Perovskia is not edible. The plant is used in Iranian folk medicine as an analgesic in rheumatic pains, treatment of leishmaniasis, fever and headache. The present study, was planned to evaluate variations in essential oil composition and contents of different Plant Organs from P. abrotanoides.
Materials and Methods In this study, different plant organs (leaf, flower and stalk) of P. abrotanoides were collected from natural habitat in North Khorasan province and their essential oil content and composition were studied. The experiment was arranged in a completely randomized design with three replications for the essential oil contents. Essential oils were analyzed by Gas chromatography (GC) and Gas chromatography–mass spectrometry (GC-MS) in respect to their chemical composition.
Results Essential oil contents of leaf, flower and stalk were 1.0, 2.3 and 0.7% (w/w), respectively. The total number of compounds identified and quantified was thirty-nine in leaf, thirty-two in flower, and thirty-five in stalk, representing 99.4, 99.8, and 98.7 % of the total essential oil, respectively. The major compounds of the essential oil were α-bisabolol (2.6-29 %), 1,8-cineole (11.4-16.5 %), camphor (10.1-21 %), α-pinene (1.9-16.2 %) and δ-3-carene (7.4-11.3 %). Results showed that leaf essential oils of the plant characterized with high content of oxygenated sesquiterpenes (41 %). Oxygenated monoterpenes, were rich in flower (42.1 %) and stalk (49.5 %). The main volatile compound identified in the leave was α-bisabolol, which reached a concentration of 29%. The content of essential oil in the flower was higher than that in the leave and stalk.
Discussion Results of the current study show that the main compounds and content percentage of essential oil were different in each plant parts. By using the hydrodistillation, 32 to 39 compounds were identified representing 98.7% to 99.4 % of the total oil components. The essential oil analysis revealed that α-bisabolol, 1, 8-cineole, camphor, α-pinene and δ-3-carene, were main essential oil constituents in all organs. The variation observed for essential oil content was 0.7% to 2.3% in stalk and flower, respectively. Chemical variation of P. abrotanoides essential oils from different plant parts, which is significant for conservation and breeding programs, can be considered by medicinal plants breeders and pharmaceutical industries for breeding and processing uses.