Analysis of the essential oils of Thymus kotschyanus L. (10 populations) from Iran

Abstract

Thymus species are well known as medicinal plants because of their biological and pharmacological properties. Thymus kotschyanus seeds (10 populations) were collected from various provinces of Iran and transferred into a new uniform environment. This study was carried out at Badiei Research Station (Qom Province, Iran) in 2008, under field conditions. The experiment was carried out as a randomized complete block design with three replicates. The content of essential oils of this species was assessed during the flowering stage, and the chemical composition of the essential oils were obtained by hydrodistillation and analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GCMS). According to populations, 17 components representing 84.57-97.08% of the total components, were identified. Oxygenated monoterpenes were the main group of constituents in all samples (87.14- 98.93%). thymol (2.45-78.65%), carvacrol (1.84-49.38%), α-terpineol (1.79-17.1%), borneol (.68-3.8%), linalool (.5-39.05%), 1,8cineole (.53- 8.39%), p-cymene (.38 - 7.74%) represented the mager compounds. The highest oil yields were obtained from Mazandaran 2 (2.5%) and Rudbar (2.3%) populations and lowest oil yields were obtained from Avan (1.1%) and Alamut (1.09%) populations. The highest level of thymol was obtained from Piranshahr (78.65%) and Semnan (60.80%) populations and lowest level of it obtained from Mazandaran 2 (2.45%), Siahkal (3.95%) populations. The highest level of carvacrol was exist in Mazandaran 2 (49.38%) and Rudbar (39.68%) populations. In this study, the linalool and α-terpineol were found as the main constituents of essential oil.