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Antimicrobial Activity and Essential Oil Composition of Five Sideritis taxa of Empedoclia and Hesiodia Sect. from Greece

Aikaterini Koutsaviti, Ioannis Bazos, Marina Milenković, Milica Pavlović-Drobac and Olga Tzakou

Department of Pharmacognosy and Chemistry of Natural Products, School of Pharmacy, University of Athens, Panepistimiopolis Zographou, 157 71, Athens, Greece

Institute of Systematic Botany, Department of Ecology and Systematics, Faculty of Biology, University of Athens, Panepistimiopolis, 157 84, Athens, Greece

Department of Microbiology and Immunology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221, Belgrade, Serbia

Department of Pharmacognosy, Faculty of Pharmacy, University of Belgrade, V. Stepe 450, 11221, Belgrade, Serbia

Abstract: Dried aerial parts of five taxa of Greek Sideritis were subjected to hydrodistillation and the oils obtained were analyzed by using GC and GC-MS. A total of 82 compounds were identified and the analysis showed important differences between the samples not only quantitatively but also qualitatively. The microbial growth inhibitory properties of the essential oils were determined using the broth microdilution method against eight laboratory strains of bacteria - Gram positive: Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus, Еnterococcus faecalis, Bacillus subtilis and Gram negative: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, a nd two strains of the yeast Candida albicans. The tested essential oils exhibited considerable activity against certain strains of the microorganisms tested, with S. lanata oil presenting MIC values to S. aureus and M. luteus comparable to those of the reference antibiotics.

Keywords: Antimicrobial activity; chemical composition; essential oils; Sideritis spp.