Phytochemical assessment and comparison of Thymus daenensis Celak. essential oil in natural habitats and field conditions

In the domestication process of medicinal plants, evaluation of qualitative and quantitative changes of active ingredients is necessary after transfer from natural habitat to field conditions. Thymus daenensis Celak is an endemic vulnerable medicinal plants of Iran, which become especially important due to high essential oil content. In this study, essential oil quantity and quality of three ecotypes from Hamedan, Markazi and Lorestan provinces were evaluated under natural habitat and field conditions. Aerial parts of plants in natural habitat and field were harvested in full bloom stage and their essential oils were obtained by water distillation method using Clevenger apparatus and analyzed by GC and GC/MS. Results indicated that essential oil content of the ecotypes was significantly different in natural habitat, but this difference was not significant in field. Essential oil of Hamedan province ecotype in field was more than natural habitat, but in two others ecotypes, essential oil content in natural habitat was greater than field conditions. Essential oil components in all ecotypes were almost same in both natural habitat and field, but there were differences in dominant components and their amount in natural habitat and field conditions. Finally, the highest content of essential oil (5 %) and thymol (75.45 %) were observed in Markazi and Lorestan ecotypes under natural habitat, respectively. As the results indicated, essential oil content and thymol of Thymus daenensis Celak was strongly influenced by habitat conditions and therefore study and determine the most appropriate secondary culture medium is necessary for domestication of this plant