The effect of distillation methods and stage of plant growth on the essential oil content and composition of Satureja rechingeri Jamzad

The aerial parts of Satureja rechingeri were collected in two stages of plant growth (at the beginning of and full flowering stage) from Ilam province in the west of Iran. The essential oils were isolated by steam, hydro- and water-steam-distillation from the aerial parts at complete flowering stage. In addition, the essential oil of plant material at the beginning of flowering was obtained by the hydro-distillation. The oils were analyzed by capillary GC and GC–MS. The highest oil yield was obtained by hydro-distillation method and the lowest by steam-distillation. The highest oil yield was obtained at the beginning of flowering (4.72% w/w). The oil yields at full flowering stage were 2.46–4.24% (the highest for hydro-distillation and the lowest for steam-distillation). three compounds were identified in the oil of S. rechingeri at the beginning of flowering, with carvacrol (56.1%), p-cymene (14.0%) and α-thujone (4.7%) as the main components. Twenty-three constituents were characterized in the oils at the full flowering stage. The main components in all of the oils were carvacrol (84.0–89.3%). rechingeri can be introduced as a rich carvacrol source in the complete flowering period.