Essential oil content and composition of Nepeta crassifolia Boiss. & Buhse under natural habitats and cultivated conditions in East Azarbaijan province

Nepeta crassifolia Boiss. & Buhse, from Lamiaceae family, is an aromatic species with medicinal properties which is endemic to Iran. The seeds and aerial parts of this plant were collected from six different regions of East Azerbaijan province. After drying, the plant aerial parts essential oil was obtained by hydrodistillation and their compounds were identified by GC and GC/MS. The collected seeds, after producing greenhouse seedlings, were planted in the field in a randomized complete block design with three replications. In the second year after planting, the flowering shoots were harvested, dried, and distilled. The results showed that there was significant differences among essential oil percentage of natural habitat samples which the highest amount belonged to "Marand" region, but the farm essential oil samples did not differ with each other significantly. The compounds nepetalactone I (4aα, 7α, 7aα) and II (4aα, 7α, 7aβ), globulol, germacrene B, caryophyllene oxide, and 1,8-cineole were identified as the main essential oil compounds of this species. The highest amount of nepetalactone I or II under the natural habitat (69% and 21.7%, respectively) and field (27.3% and 51.5%, respectively) conditions belonged to "Misho" region in "Marand". "Sarab" region also had the highest amount of nepetalactone II under the natural habitat and farm conditions compared to the other samples. The highest amount of 1,8-cineole (21.8%) in the oil was also obtained from the natural habitat of "Kharil" region.