Antibacterial Activity and Chemical Constitutions of Melissa officinalis L.

Abstract

Two different isolation techniques, conventional hydrodistillation (HD) and solvent free microwave extraction (SFME) have been used to analyze the volatile constituents from the aerial parts of M. officinalis by gas chromatography coupled to mass spectrometry. The means of relative peak area (%) for every compound calculated with statistical analysis. Hydrodistillation and solvent free microwave extraction techniques produced quantitatively (yield, 0.5 % and 0.4 %) and qualitatively (aromatic profile) almost similar essential oil. E-citral (41.01-33.81 %), Z-citral (35.4-23.06 %), β-caryophyllene (8.38-8.09 %) and caryophyllene oxide (4.24-20.8 %) were identified as major constituents of this Iranian endemic specie. Besides, the hydrodistilled oil of M. officinalis was evaluated for antibacterial activity against gram-positive and gramnegative bacteria using agar dilution method and minimum inhibitory concentration (MIC) were determined. The hydrodistillation oil of M. officinalis showed antibacterial activity against Bacillus subtilis (gram-positive) growth with a MIC value of 25 and 150 μg/mL for Escherichia coli (gram-negative) as efficiently inhibition.