Comparison of the volatile composition of Stachys pubescence oils obtained by hydro distillation and steam distillation.

The oils obtained by hydrodistillation and steam distillation of the aerial part of Stachys pubescence Ten. was analyzed by GC and GC/MS. Water distilled essential oil of the aerial part of S. pubescence, was rich in fatty acids like hexadecanoic acid and linoleic acid and also benzaldehyde and spathulenol whereas the steam distilled oil of the plant contained hexadecanoic acid, spathulenol and eugenol. Both of oils were rich in fatty acids (36.6 and 27.9%, respectively). Moreover, the content of oxygenated mono and sesquiterpenss were defined higher in steam distilled oil than hydrodistiledd oil (24.5, 17.2 and 6.1, 15.5%, respectively). In conclusion it seems that oxygenated terpenoids were trended to steam distillation method more than hydrodistillation, respectively.