Essential oil composition and metabolites changes of Artemisia melanolepis Boiss at different phenological stages

Artemisia melanolepis Boiss is an endemic species in Iran distributed in north and north west of the country. In the present work, metabolites’ content of the aerial parts of A. melanolepis was analyzed at three growth stages. The non-volatile primary and volatile secondary metabolites of the plants were obtained by extraction and hydro distillated methods, respectively, and then were analyzed using a GC-MS. Our results showed that the non-volatile primary metabolites from amino acids, organic acids, sugars, and sugar alcohols declined considerably from the vegetative state to fruiting period of the plants. The results also indicated that thymol was the main constituent of the volatile oils at all phonological stages with various percentages in each stage. The major volatile secondary metabolite was alpha-terpineol at the vegetative and flowering stages (6.09 and 6.92%, respectively), followed by 4-carene (4.96%) at the fruiting stage. It was concluded that the metabolites profile of A. melanolepis was considerably altered at different stages of the life cycle.