Essential oils obtained from the aerial parts of Phlomis bucharica, P. salicifolia and P. sewerzowii were determined using GC-FID and GC-MS methods. A total of 76 components were identified in the three species representing 97.12, 88.34, and 96.41% of the whole oil, respectively. High percentages of thymol (20.41%) and camphor (14.46%) exist in P. bucharica oil. Methyl palmitate predominates in P. salicifolia oil representing 51.15% whereas thymol (35.76%) is the major constituent in P. sewerzowii essential oil. GC-MS analyses showed that P. bucharica and P. sewerzowii are more closely related comparable to P. salicifolia. The antimicrobial activity of the essential oils was assessed against different microorganisms using agar-disc diffusion and broth microdilution assay. Among the three tested species, the essential oil of P. salicifolia showed the highest antibacterial activity.
Keywords: GC-FID; GC-MS; Lamiaceae; Phlomis; antimicrobial activity; essential oils.