Comparison of oil content and composition of five adapted Eucalyptus species in south Iran

In this investigation, the leaves of five Eucalyptus species as Eucalyptus microtheca F. Muell, E. gongylocarpa Blakely, E. gillii Maiden, E. woodwardi Maiden and E. salubris F. Muell were collected from two regions of Khuzistan province (Shushtar and Dezful, South Iran) in spring. After drying the plant materials in shade, their essential oils were obtained by hydro-distillation. The oils were analyzed by capillary gas chromatography, using flame ionization and mass spectrometric detection. The oils of E. microtheca were obtained at yields of 0.43% and 0.37% (w/w) from Shushtar and dezful, respectively. These yields were 2.37% and 1.78% for E. gongylocarpa, 3.5% and 3.9% for E. gillii, 1.18% and 1.13% for E. woodwardi, 2.05% and 1.02% for E. salubris. The main compounds of E. microtheca oils were 1,8-cineole (26.7% and 16.9%), P-cymene (14.8% and 20.4%) and a-pinene (12.5% and 12.0%) in the Shushtar and Dezful samples, respectively. The major constituents of E. gongylocarpa oils were 1,8-cineole (66.8% and 78.6%) and a-pinene (5.2% and 7.2%). The main components of E. gillii oils were 1,8-cineole (58.5% and 81.3%) and a-pinene (13.9% and 11.0%). The main compounds of E. woodwardi oils were 1,8-cineole (58.7% and 45.1%) and a-pinene (23.1% and 21.4%). The major constituents of E. salubrisoils were 1,8-cineole (62.0% and 71.0%) and a-pinene (8.0% and 10.0%). Differences in the percentage of the main components of these oils in two regions could be due to some differences in habitats like soil structure or humidity.