Chemical content of the aerial parts essential oil from rosemary, Rosmarinus officinalis L. (Lamiaceae) samples collected from Kermanshah province in the west of Iran

Rosemary (Rosmarinus officinalis L.) is one of the evergreen and fragrant medicinal plants belonging to Lamiaceae (Labiatae). In the present research, the chemical content of the essential oil isolated from its aerial parts (leaf and flower) was investigated. Accordingly, the mature plant was collected in its natural habitats from Kermanshah province in the west of Iran, dried gradually under the shadow (25 °C), pulverized, its essential oil isolated, and finally analyzed by Gas Chromatography-Mass Spectroscopy. The results showed that the important compounds were available in the essential oil of this medicinal plant; the number of them reached 147. Run (retention) time for total compounds was determined as 38.358 min. Also, 27 compounds had > 1% share in total volume; among them, alpha-pinene, (-)-bicyclo (peak 4, 5.448 min, 7.50%), bicyclo [2.2.1] heptan-2-one (peak 29, 9.848 min, 5.92%), bicyclo [3.1.1] hept-3-en-2-one (peak 40, 11.771 min, 5.48%), 1,8-cineole 2-oxabicyclo (peak 17, 7.256 min, 4.60%), and acetic acid 1,7,7-trimethyl (peak 45, 14.506 min, 4.29%) were five major constituents, respectively. Moreover, 56 different compounds contained ≤ 0.1% share in total volume and were distinguished as minor compounds. Accordingly, this fragrant medicinal plant has important essential oil constituents which could be considered in medical, pharmacology, and toxicology.