Chemical composition and biological activities of volatile fractions from three Tunisian cultivars of olive leaves

The chemical composition, antibacterial, and antifungal activities of the volatile fractions from fresh and dried leaves of three Olea europaea L. cultivars from Tunisia (Neb jemel, Chemchali and Chemlali) have been studied. The volatile components were obtained via hydrodistillation and analyzed by GC-MS. The major constituents were (E)-3-hexenol, 3-ethenylpyridine, (E)-beta-damascenone and phenylethyl alcohol, but their percentages varied according to the treatment of the leaves. Antioxidant activities were determined applying DPPH and ABTS(+) radical-scavenging assays. In general, antioxidant activity of the volatile fraction obtained from fresh leaves was superior to that obtained from dried leaves. The antibacterial and antifungal activities of the volatile fractions from fresh and dried leaves were evaluated against four bacterial and four fungal strains. The volatile fractions showed significant antibacterial and antifungal effects. However, some differences were observed in the response for several microorganisms, because of the variability of the composition. This work gives further knowledge for extensive development of this medicinal plant.