Investigation on chemotypes of Thymus pubescens Boiss.et Kotschy ex Celak based on essential oil compounds in E-Azerbayjan province

The current study was aimed to investigate the essential oil of Thymus pubescens Boiss. et Kotschy ex Celak chemotypes in five regions of E-Azerbayjanprovince. Samples were collected at the flowering atage. Hydrodistillation method was used to obtain essential oil. Quantitative and qualitative analysis was done by GC and GC/MS methods. Twenty six compounds were determined in the essential oil of experimental sites. Cluster analysis، based on these components with WARD method، showed that five areas were divided into three clusters، so that the first cluster was related to the Sahand area chemotype، the second cluster was related to the Mishoo chemotype and the third cluster included common chemotype in Malekan (Egdelou)، Kaleibar (Yuzband) and Maraghe (Kordedeh). Our results showed that the highest and lowest amount of essential oil was recorded for the first chemotype (Sahand، 0. 31%) and the third chemotype (Egdelou، 1. 34%)، respectively. According to the Principal Coordinate Analysis the major compounds of essential oils were as follows: in the first chemotype: р-cymene (4. 3%)، n-nonanal (9. 8%)، methyl ether thymol (10. 6 %)، thymol (30. 9 %)، thymyl acetate (13. 5%); in the second chemotype: p-cymene (4. 1%)، γ-terpinene (6. 2%)، carvacrol (82. 1%); in thr third chemotype p-cymene (7. 2-1. 6%)، γ-terpinene (6. 5-2. 2%)، thymol (65. 6-27. 6%)، carvacrol (25. 4-3. 7%).