Chemical composition and antibacterial activity of Mentha pulegium L.and Mentha spicata L. essential oils

The analysis and identification of essential oils hydrodistilated from two mint species (Mentha spicata and Mentha pulagium) by means of gaz chromatography and mass spectroscopy was realized in this investigation. In addition, their antagonistic activity against some pathogenic bacteria was screened. Acceptable yield (1.0 and 0.87 % for M. Pulagium and M. Spicata respectively) was obtained. From the leaf essential oil Mentha spicata 57 compounds were separated, representing 97,022% of the total essential oil mass from which 44 compounds were elucidated. The major compound was carvone (59.40 %), other components present in appreciable contents were: limonene (6.12%), 1,8-cineol, germacrene- D (04.66%), β-caryophyllene (2.969 %), β-bourbonene (2.796 %), α-terpineol (1.986 %) , Terpinene-4-ol (1.120 %). The essential oil of Mentha pulegium, 43 compounds were separated, representing 99.52 % of the total essential oil mass from which 29 compounds were elucidated. The major component was pulegone (38.815 %), other components present in appreciable contents were: menthone (19.240 %), piperitenone (16.528 %), piperitone (6.348 %) and isomenthone (6.096 %), Limonene (4.293 %), Octaan- 3-ol (1.854 %). Furthermore, screening of the two essential oils for their antagonistic activity against pathogenic bacteria reveals that they have not an appreciable activity except that observed against Streptococcus pyogenes (20 and 16 mm for M. Spicata and M. Pulagium respectivelly). This growth inhibition was obtained by the undiluted essential oils. However, more research on the factors influencing the biosynthesis and bioactivity of essential oils is needed as essential oils are gained important applications in food and pharmaceuticals industry.