The essential oils of Salvia officinalis L. collected at two different altitudes in Syrian coastline were analyzed by gas chromatography. Plant's development stage and the ecological factors had impact on the qualitative composition of S. officinalis essential oil. Although, the major components of the essential oils extracted from plants grown at both altitudes were 1,8-cineol, camphor, borneol, α-pinene, β-pinene, camphene, β-myrcene and caryophyllene, their percentage changed according to the altitude. S. officinalis essential oil was for its antibacterial activities by using Gram-positive and negative bacteria. Both Staphylococcus aureus and Streptococcus group D were efficiently inhibited after 10 min of contact at oil concentration of 20 µl/ml. The inhibitory effect of the essential oil on Candida albicans was total and definitive within a minimum of contact time and oil concentration. But the essential oil showed a temporary bacteriostatic effect on Escherichia coli, Salmonella typhi, as well as Pseudomonas aeruoginosa. In comparison with most known antibiotics, the efficiency of S. officinalis essential oil was much better, especially against bacteria resistant to antibiotic.

In order to detect the genetic variation and relationship among Thymus vulgaris populations collected from five different provinces in Syria, Random Amplified Polymorphic DNA (RAPD) analysis was applied. A total of 198 bands were obtained using 27 primers. Polymorphism was 90.91% while the polymorphism of the total bands was 78.73%, which indicated a close relationship among some populations. Populations of T. vulgaris were characterized by 37 unique bands of which eight were negative. Dendrogram based on Percent of Disagreement Values (PDV) matrix revealed two major sub-clusters in which the populations from different geographic locations constituted distinct groups. The highest similarity degree was more than 90% among populations from Suwayda. These findings indicated a significant relationship between the studied populations and their geographic locations.