Document Type : Research Paper

Authors

• F. Askari
• F. Sefidkon
• M. Mirza

Research Institute of Forests and Rangelands, P.O. Box 13185 - 116, Tehran, Iran

Abstract

One of the more distributed of The genus of Thymus is T. pubescens that is widespread in Tehran provinces up to 1800 m height and often widespread on flat and rocky surface.
The aerial parts of Thymus pubescens were collected at four various localities in the Tehran province: Lar valley and Damavand (East of Tehran province), Sirachal and Fasham (Northwest of Tehran province). Essential oils were isolated by steam distillation from the plant material at two stages, before flowering (BF) and at full flowering (FF). The yields arranged between 0.34% and 0.86% at BF stage and between 0.40% and 2.03% at FF stage. In most sites of collection the oil content at BF stage was less than FF stage and the oil percentage of plant material from Lar valley and Damavand was more than of Sirachal and Fasham.
 At BF stage 25 compounds and at FF stage 26 compounds were characterized by means of GC and GC/MS. Major constituents were: carvacrol, thymol, g-terpinene, r-cymene, borneol, methy carvacrol, b-caryophyllene, 1,8-cineol + limonene and Geraniol.
Twenty-three constituents were common at two stages. Geranyl acetate and thymyl acetate were found just at BF stage and geranial, nerol, and thymodihydroquinone were found just at FF stage.

Keywords

• Thymus pubescens Boiss. et Kotschy ex Celak
• Lamiaceae
• essential oil
• Carvacrol
• Thymol
• γ-terpinene
• ρ-cymene and geraniol