4.

Chemical Composition, and Antibacterial and Free-Radical-Scavenging Activities of the Essential Oils of a Citronellol Producing New Chemotype of Thymus pubescens Boiss. & Kotschy ex Celak

Hossein Nazemiyeh, F. Lotfipoor, Abbas Delazar, Seyed M. Razavi, Solmaz Asnaashari, N. Kasebi, A-H. Talebpour, Lutfun Nahar and Satyajit D. Sarker

Research Center for Pharmaceutical Nanotechnology, Faculty of Pharmacy, Tabriz University of Medicinal Sciences, Tabriz, Iran

Faculty of Pharmacy and Drug Applied Research Center, Tabriz University of Medicinal Sciences, Tabriz, Iran

Department of Biology, Faculty of Science, Mohaghegh Ardabili University, Iran

East Azerbaijan Research Center for Agriculture and Natural Resources, Tabriz, Iran

Drug Discovery and Design Research Division, Department of Pharmacy, School of Applied Sciences, University of Wolverhampton, City Campus South, MA Building, Wulfruna Street, Wolverhampton WV1 1LY, England, UK

Department of Pharmacy, School of Applied Sciences, University of Wolverhampton, MM Building, Molineux Street, Wolverhampton WV1 1SB, England, UK

Abstract: The composition of the essential oils obtained from the flowering aerial parts of two populations of Thymus pubescens, collected from Mishov-Dagh, was determined by the GC-MS analyses. A total of 18 compounds, representing about 95% of the total oils, were identified in both samples of the essential oils. The essential oils of these two populations showed the presence of high amounts of citronellol (42.0% and 42.6%), geranyl acetate (14.0 and 14.0%), geraniol (13.0 and 13.1%), citronellyl acetate (3.9 and 3.8%), L-linalool (7.8% and 7.9%), cis-nerodiol (5.9% and 5.5%) and citronellyl acetate (3.9% and 3.8%). However, in the published literature, carvacrol, thymol and p-cymene were reported to be the major compounds in T. pubescens. This significant difference in the composition of the essential oils was a clear evidence of chemical polymorphism with in the T. pubescens taxon, suggesting that these two populations of T. pubescens were in deed a new chemotype of this species, and the name Thymus pubescens Boiss. & Kotschy ex Celak chemotype Citronellol for this new chemotype has been proposed . The antibacterial and free-radical-scavenging properties of the essential oils of T. pubescens have also been evaluated.

Keywords: Thymus pubescens ; Lamiaceae; chemotype, essential oil; citronellol; DPPH; antibacterial activity