Document Type : Research Paper
Authors
1 Research Institute of Forests and Rangelands, P.O. Box 13185-116, Tehran, Iran
2 Research Center of Natural Resources and Animal Husbandry, Hamedan, Iran
Abstract
The genus of Nepeta presents 67 species in Iran, most of them are endemic. One of theses endemic species is N. heliotropifolia. In this research the essential oil of N. heliotropifolia was investigated in three different stage of plant growth.
The aerial parts of N. heliotropifolia at before flowering, beginning of flowering and complete flowering were collected from Hamedan province.
Essential oils isolated by hydro-distillation from the aerial parts of three samples, were analyzed by a combination of capillary GC and GC/MS. The yields of essential oils were obtained 0.75%, 0.63% and 0.4% (w/w) respectively. So the oil yield of N. heliotropifolia was decreased from before flowering stage to complete flowering stage.
Thirty-six components were identified in the oils. The main constituent of the essential oil at before flowering stage was limonene (40.1%), that decreased by plant growth. The second main component of the oil in this stage was b-pinene (11.1%), that increased to 23.3% in the beginning of flowering, then decreased in fool flowering. The other main compounds of the oils were 1,8-cineole, b-caryophyllene, (Z)- b-farnesene, g-mmurolene abd bicyclogermacrene.
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