Essential oil analysis - The oils were analyzed using a Hewlett-Packard 5971 GC/MS instrument employing the following conditions: column: Dimethylpolysiloxane DB-1 coated fused silica capillary column (30 m x 0.25 mm); carrier gas: He (1 ml/min); injector temperature: 250°C; detector temperature: 200°C; column temperature: 35–180ºC at 4ºC/min then 180–250ºC at 10ºC/min; mass spectra: electron impact 70 eV. The identification of the constituents was performed by computer library search, retention indices and visual interpretation of the mass spectra (Craveiro et al. 1984, Adams 2001). The identified constituents are listed in their order of elution from a non-polar column in Table I.