The qualitative and quantitative analysis of Nepeta eremokosmos Rech.f. in its natural habits (Semnan province) during the phenological stages

Background: The genus Nepeta comprise various annual and perennial plants with 250 species in different parts of the world. 67 species of Nepeta have been reported in Iran in which 39 ones are endemic to Iran. Nepeta eremokosmos Rech.f. is an endemic plant growing in the Semnan of Iran. Objective: The present study was conducted to assess the quantitative and qualitative properties of Nepeta eremokosmos in its natural sites (1700 to 2100 m above sea level) during phenological stages (vegetative and flowering). Methods: the aerial parts were collected in spring and summer of 2017 and the EO was measured via hydrodistillation method. Water-distilled volatile oil from the aerial parts of Nepeta eremokosmos was analyzed by a combination of GC and GC/MS. Results: The results showed the highest EO content was observed in interaction of Arvaneh and flowering stage (1.9 %), while the lowest value was found in Aftar and vegetative stages (0.43 %). There was no significant change for trans-pinocarveol during phenological stages. This component in Arvaneh was slightly higher than Aftar. Arvaneh due to more deserved edaphic and climatic conditions induces greater essential oil content and also increased 1,8-cineole and trans-pinocarveol compared to Aftar. In the growing stages, flowering had greater EO content and 1,8-cineole and in comparison with vegetative stage. Conclusion: To sum up, flowering stage is the best time to reach the optimum EO and 1,8-cineole for both Arvanh and Aftar sites.