Biological Activity and Composition of the Essential Oil of Dracocephalum Moldavica L. Grown in Iran

The biological activity and composition of the essential oil of the aerial flowering parts of D. moldavica have been investigated. The oil analysis was performed by GC and GC-MS. Thirteen compounds were identified, representing 99.8% of the oil. Oxygenated monoterpenes (96.3%) were found to be the principal group of compounds, of which neral, geranial, geranyl acetate and geraniol with 32.1, 21.6, 19.9 and 17.6% of the total oil were the main constituents, respectively. The in vitro antimicrobial activity of the essential oil and its main components, citral, geraniol and geranyl acetate, showed that all of the tested microorganisms were highly inhibited by the essential oil with inhibition zones ranged from 15 – 41 mm for bacteria and 29 – 30 mm for fungi. The most sensitive microorganisms were Bacillus subtilis, Staphylococcus aureus and S. epidermidis with the lowest MIC values of 0.9 mg/mL. Considering sensitivity screening, it is conceivable that the activity of the oil from D. moldavica could be attributed mainly to the presence of citral.