Abstract

Water-distilled essential oils of wild and micropropagated Origanum sipyleum L. (Lamiaceae), a herb native to Turkey, were analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). Eighteen components were characterized. In wild plants, the major constituent of aerial parts was α-cadinol (23.41%), and of flowers, germacrene-D (20.13%). Thymol (48.55%) and α-cadinol (11.46%) were found as the major components in the micropropagated plants. The essential oils of wild O. sipyleumexhibited antimicrobial activity against all bacteria tested except Pseudomonas aeruginosa,with minimum inhibitory concentration (MIC) values ranging from 500 to 1500 µg/ml. The antimicrobial activity of the essential oils of micropropagated plants was slightly lower than that of the essential oils of wild plants.

Key words:  Origanum sipyleum, Lamiaceae, essential oils, thymol, α-cadinol, germacrene-D, micropropagation.