Chemical characterization and evaluation of biological activity of essential oil of Juniperus phoenicea of Tunisia

Isolation of essential oil from dried leaves of Juniperus phoenicea of Tunisia were obtained with two different methods: by means of the classical hydrodistillation (HD) and by using carbon dioxide in the supercritical state (SFE). Operative conditions adopted in SFE were: pressure, 90 bar and temperature, 50 °C. The leaf volatile oil was made up of germacrene D (12.6 %), (E)-caryophyllene (7.2 %), cubebol (6.5 %), ô-cadinene (6.0 %) and Ot-terpinyl acetate (5.6 %). The corresponding yield (w/w) was 0.64 %. The essential oil obtained by hydrodistillation at a yield of (0.26 %) was characterized by Ot-pinene (16.4 %), ô-cadinene (8.1 %) germacrene D (8.0 %), a-terpinyl acetate (7.1 %) and (E)-caryophyllene (5.8 %) as main constituents. These oils failed to inhibit three microorganisms tested (Pseudomonas aeruginosa, Escherchia coli and Enterococcus faecalis) at the highest concentration tested (MIC > 10 %), but they exhibited a very good activity against Candida albicans at MIC 0.0125 %. Moreover, both hydrodistilled and supercritical extracted oils were found to inhibit Staphylococcus aureus growth, in special way the former was more active at concentration of 0.6 % v/v. © 2008 Taylor & Francis Group, LLC.