Chemical Composition and Antimicrobial Activity of the Essential Oils of Micromeria thymifolia (Scop.) Fritsch., M. dalmatica Benth., and Satureja cuneifolia Ten. and Its Secretory Elements

Abstract

Light yellowish, pleasant-smelling essential oils were obtained in 0.3%, 1.3%, and 0.8% yields from the aerial parts of S. cuneifolia Ten., M. thymifolia (Scop.) Fritsch., and M. dalmatica Benth, respectively. Thirty-four compounds were identified in the oil of M. dalmatica representing 98.7% of total oil composition, while in the oil of M. thymifolia, 21 were identified representing 78.2% of total oil composition. The major compounds in the oil of M. thymifolia included pulegone (50.4%), piperitenone (10.3%) and piperitenone oxide (4.3%), while the oil of M. dalmatica was rich in pulegone (26.7%), piperitenone (21.8%) and piperitenone oxide (25.4%). Fifty-five compounds were characterized in the oil of S. cuneifolia, representing 92.1% of total oil composition. Linalool (19.9%) and alpha-pinene (12.3%) were found to be the dominant compounds. Antimicrobial activity was noticed in all examined oils with MIC Values ranging from 5.6-54 mu g/mL. The most active was the oil of S. cuneifolia, which completely inhibited the growth of mostly all tested microorganisms at the lowest supplied concentration. Glandular trichomes (both peltate and capitate) and nonglandular, uniseriate, simple hairs were distributed on abaxial and adaxial surface of the leaves, calyces and stem in all examined species.