Andmicrobial Activity and Volatile Constituents of Essential Oils from Leaf and Stem ofStachys byzantinaC.Koch

Hydrodistillation of leaves and stems of Stachys byzantina C.Koch. (Lamiaceae) yielded 0.1 %and 0.08 %( v/w) essential oils, respectively. GC-MS analysis allowed identification of 15 components, which made up 94.6 % of the total oil from the leaves, while only 10 compounds (95.6 %) were identified in the stems. The main components of the leaf oil were germacrene- D (37.0 %), valeranone (11.9 %), n- nonadecane(6.8 %), 2-pentadecanone-6,10,14-trimethyl (6.5 %), β-elemene (6.4 %) and α-bisabolol (4.8 %). In the stem oil, the main constituents were nerolidol (57.8 %), thymol (19.0 %) and n-nonadecane (4.8 %). The antimicrobial activity was tested on six bacterial strains and two fungal strains, using the agar diffusion method. Diameters of growth inhibition zones were measured. The most sensitive microorganisms were, in order: Enterococcus faecalis > Pseudomonas aeruginosa > Klebsiella pneumoniae > Bacillus subtilis > Candida albicans (ATCC 10259) > Candida albicans (ATCC 24433) > Staphylococcus aure...