Composition and Antifungal Activity of Peppermint (Mentha piperita) Essential Oil from Iran

Essential oil of Mentha piperita was analyzed by GC and GC-MS and evaluated for in vitro antifungal activity against Dreschlera spicifera, Fusarium oxysporum f.sp. ciceris and Macrophomina phaseolina. Thirty-five components have been identified in the essential oil of M. piperita. The major compounds identified in the oil were menthone (30.63 %), menthol (25.16 %), menthofuran (6.47 %), beta-phellandrene (5.59 %), isomenthone (4.74 %), menthol acetate (4.61 %), pulegone (4.39 %), beta-caryophyllene (3.05 %), neomenthol (2.83 %), 1,8-cineole (2.15 %). The antifungal assay was determined by agar dilution method with five concentrations of peppermint oil (up to 1600 ppm). The oil was found to be effective against these fungal pathogens under laboratory screening. The antifungal activities of the oil increased with an increase in the concentration. Minimum effective concentrations of the oil against fungal pathogens were also different. The fungistatic and fungicidal activity of the oil was determined. Results of fungistatic and fungicidal activities showed that peppermint oil in these concentrations have no fungicide activity.