Essential oil composition of Teucrium divaricatum Sieb. ssp. villosum (Celak.) Rech. fil. growing wild in Lebanon.

Teucrium divaricatum Sieb. ssp. villosum (Celak.) Rech. fil. is a medicinal plant used in Lebanon. The hydrodistillation of the aerial parts of T. divaricatum yielded 0.27% (wt/wt) of essential oil; gas chromatography and gas chromatography/mass spectrometry analysis enabled the identification of 60 compounds representing 94.5% of the total oil. On the whole, the oil was constituted mainly by sesquiterpenes (64.6%), particularly sesquiterpene hydrocarbons (50.0%). The most abundant compounds were (E)-caryophyllene (30.1%) and caryophyllene oxide (6.1%). The in vitro activity of the essential oil against some microorganisms in comparison with gentamicin by the broth dilution method was determined. The oil exhibited a good activity as an inhibitor of growth of Gram-positive bacteria.