Chemical Composition And Antibacterial Activity Of Essential Oil Of Flowers Of Nepeta binaludensis From Khorasan

Difference in the essential oil and solvent extract composition of Nepeta species influenced by ecological conditions and type of the organ in which essential oil are produced and/or accumulated have also been reported. this study was designed to examine the chemical composition and antimicrobial activity of the essential oils of flowers of Nepeta binaludensis Jamzad. in flowering stage which grows wild in binaloud mountainous. The composition of the essential oil hydrodistilled from the flowers of N. binaludensis, was analyzed by gas chromatography-mass spectrometry (GC-MS). Identification of the components was based on GC retention indices computer maching with wiley GC-MS library, and by comparison of the fragmentation patterns of the mass spectra with those reported in the literature(1). Then for evaluation of antibacterial effects of the essential oil, disc diffusion method through the measurement of the inhibitory zone diameter and micro broth dilution for determining the minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC), on several standard bacteria, were used. Essential oil yield of dried plants obtained by hydrodistillation was 0.92 (w/w %). Twenty-seven components were identified, representing 98.2% of the total oil composition. The major components in flowers oil were, 1,8-cineole (52.0%), 4aβ,7a,7aa-Nepetalactone (17.5%), β-Pinene (4.5%), and δ-3-Carene (4.4%). Amongst them monoterpenes and oxygenated monoterpenes were predominant. Also essential oil inhibited growth of all studied bacteria. Among them, zone of growth inhibition was larger in Sh. dysenteriae, which is in consistent with the results of micro-broth dilution method.This research results showed that N. binaludensis essential oil has a moderate effect on the studied bacteria. Its effect on gram negative bacteria was more than gram positive bacteria.