Composition of the Essential Oils of Turkish OriganumSpecies with Commercial Importance

ABSTRACTIn Turkey Origanumis represented by 23 species comprising 31 taxa. Commercially important Origanumspecies include O. onites, O. majorana, O. minutiflorum, O. vulgareand O. syriacum.These species are annually exported in quantities exceeding 4,000 tons. GC and GC/MS profiles of the essential oils of the above mentioned Origanumspecies are presented in a comparative manner. Oils from O. vulgaresubsp. hirtumwere found to contain carvacrol (23.4–78.7%) and thymol (0.01–39.8%), while O. syriacumvar. bevaniicontained carvacrol (42.5%) and thymol (24.8%). Oils from O. majoranaand O. minutiflorumappeared to be more stable in carvacrol, containing 78.3–79.5% and 75.1–83.6% respectively. Two chemotypes of O. oniteswere found: a carvacrol-type (carvacrol (66.5–80.4%)) and a linalool-type (linalool (90.0–91.9%)).