Comparison of essential oil yield and composition of flowers, leaves, stems and flowering shoots of Tanacetum polycephalum Schultz. Bip. subsp. polycephalum

Tanacetum polycephalum, belonging to the Asteraceae family, is a perennial and aromatic species with numerous medicinal properties. In this study, in order to evaluate and compare the quality and quantity of essential oil of flowering shoots and each of its parts (flowers, leaves and stems), the seeds of T. polycephalum Schultz. Bip. Subsp. polycephalum was collected from Kurdistan province (around the Qorveh city) and cultivated in the Alborz Agriculture Research Station, associated to the Research Institute of Forests and Rangelands. After collecting the aerial parts in full flowering stage, organs were separated and dried in the shade and essential oil extraction was carried out by hydro-distillation. The essential oils were analyzed by using a gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The highest yield of essential oil (W/W relative to dry weight) was obtained from flowering shoots (0.87%) and the lowest yield was obtained from stems (0.12%). The oil yield of leaves and flowers was calculated to be 0.61% and 0.46%, respectively. The main compounds in the oil of flowering shoots were camphor (35.5%), cis- chrysanthenol (10.1%) and α-terpinene (9.5%). Camphor (25.4%), α-terpinene (13.2%), and cis-chrysathenol (11.2%) were found in the essential oil of leaves. Trans-β-farnesene (39.7%) and camphor (8.5%) were the main components in the essential oil of stems. According to the results, if camphor and cis-chrysanthenol is the target of essential oil extraction, distillation from flowering shoots and leaves is recommended; however, to achieve the most amount of trans-chrysanthenyl acetate, distillation from flowers is recommended.