Fakhri A. Elabbar, Yacoub M. EL-Barasi and Madiha W. M. ALawamy
A total of 11 samples of the aerial part of Origanum cyrenaicum were analysed fresh and dry for their essential oil contents and for the effect of seasonal variation on the concentration of these oils. Compounds characterized by gas chromatography and mass spectrometry were divided into 4 groups according to their molecular structure. The first group which contain monoterpenes hydrocarbon This group was in the highest concentration in spring during the month of May. The second group was the oxygenated form showed the highest concentration in spring during the month of May. While the third and fourth groups were the sesquiterpene hydrocarbon and the oxygenated. Showed high concentrations in the fall season during the month of October. Most compounds found were (D-germacren-4- ol, 33.57%)-(caryophyllene oxide, 28.49%) - (trans-caryophyllene, 24.76%) - (epizonarene, 21.94%) - (germacrene- D, 17.43%) The high concentration of compound D-germacren-4-ol, (33.57%) occurred in October in fall season. The results of this study indicate that Origanum cyrenaicum is rich sesquiterpene hydrocarbons and oxygenated sesquiterpenes oils specially during the fall season
