Studies of Mediterranean oregano populations.: VII:: Chemical composition of essential oils of carvacrol-rich oregano of various origins

Six species of oregano were studied: Origanum compactum Benth., O. dictamnus L., O. dubiuni, Boiss., O. minutiflorum, Schwarz et Davis, O. onites L. and O. vulgare ssp. hirtum Ietswaart. Collected at their natural sites, sown, planted and oils isolated at the CNPPMAI. The oils were analyzed by GC and GC/MS; 118 constituents were identified. All species presented a carvacrol chemotype (60 - 90%) accompanied by various chemical forms, such as a thymol-rich type, as in O. dictamnus, O. dubium and O. vulgare ssp. hirtum, in which its levels ranged widely (20 - 90%), or linalool-rich (27 - 90%), as in O. onites and O. dubium.