Investigatingthe Antibacterial Properties and Chemical Components in the Essential Oils of Thymus eriocalyx (Ronniger)Jalas in Peresk Area (in AlashtarLorestan Province)

Lamiaceae family has about 200 genus and 4000 species including Thymus. Most of the plants in this family have essences which can be applied in different pharmaceutical, cosmetics, hygienic, and food industries. Thymus genus hasdifferent species which are spread in different provinces of Iran. The purpose of the present study is to investigate the existing compounds in the essential oil obtained from the shoot organs of this plant species and their antibacterial impact. Samples were collected at the flowering stage from the plants in PereskinAlashtarof Lorestan province in 2011.The produced samples were shadow dried. To study the anatomical properties, the samples were stained with brown Bismarck and methyl green. Their essences were extracted by means of Hydrodistilation method using Clevenger device. Afterwards, the components and percent of the essential chemical compounds were recognized and separated completely using GC and GC/MS devices. Plate sink strategy was used to investigate the antibacterial impact of the essential oil of the species against four g+ and g-pathogen bacteria (i.e. Staphylocococus Aureus, Escherichia Coli, Pseudomonas aeroginosa, & β.streoptocococs) with the assistance of MAHmedium and measuring thediameter of inhibition zone. The laboratory analyses indicated that the species under study had anatomical similarities with other species such as T. eriocalyxand T. kotschyanusinLorestan. Based on the retention volume, retention time, Kovats retention index, and the comparison of these parameters with the standard components, the results revealed that this species has 45 components in its essence which together comprise 98.85% of the total essence. The main components included: Thymol (42.60%), Carvacrol (32.33%), Cymol (4.05%), γ-terpinene (3%), and Borneol (2.12%).The results confirmed the findings of the previous research with respect to the main compounds in the essence. However, the obtained amounts were different from the previous studies which can be attributed to the impact of the environmental factors or the strategies applied for collecting the samples on the biosynthesis of the essence. These factors include: the time and place of collection, plant growth stage, and the climatic changes. In addition, the results confirmed that the essence of the aforementioned species has antibacterial impacts.