Investigation ٍof the essential oil composition of five species from aromatic plants of Iran.

In this project, Foeniculum vulgar, was cultivated in Research Station of Alborz in Karaj. The plant material (flowering shoots, florescence with unripe seeds and ripe seeds) collected in three stages. Four other species named Thymus kotschyanus, prangos uloptera, Nepeta glomerulosa and Echinophora sibthorpiana were collected from their natural growth regions. The essential oils, from different parts of Foeniculum vulgar in different stages of plant growth and the aerial parts of other plants (and seeds of prangos uloptera), were obtained by distillation methods and the yields were calculated. The oils were analyzed by capillary GC and GC/MS. In addition, the effect of distillation methods and stage of plant growth on oil content and composition of Thymus kotschyanus was studied. The results showed the highest oil yield was obtained by hydro-distillation and the steam distillation produced the lowest oil yield. The oil yield of Thymus kotschyanus related to distillation methods and stage of plant growth were 0.28%-1.80%. The main components in all oils were carvacrol (46.74%-61.23%), thymol (7.51%-26.92%), gamma-terpinene, P-cymene and borneol. Chemical composition of flowering shoots, florescence with unripe seeds and ripe seeds of Foeniculum vulgar were characterized. The main components of all parts were E-anethol (48.7%-75.2%), limonene (8.8%-25.6%) and fenchone (7.9%-10.9%). The percentage of these compounds was changed in different stages of plant growth. Twenty-eight compounds were identified in the essential oil of Nepeta glomerulosa with alpha-pinene (9.4%), geranyl acetate (9.3%), limonene (8.2%) and caryophyllene oxide (8.0%) as main components. Twenty-one compounds in the aerial parts oil and twelve compounds in seed oil of prangos uloptera were found. The main compound of aerial parts oil was beta-caryophyllene (18.2%) and that of seed oil was alpha-pinene (41.9%). Seventeen compounds were characterized in the essential oil of Echinophora sibthorpiana. The major components were delta-3-carene (31.8%), alpha-phellandrene (31.0%) and methyl eugenol.