Antifungal activity and volatile organic compounds analysis of essential oils from Cymbopogon species using solid-phase microextraction-gas chromatography-mass spectrometry

The essential oils extracted from Cymbopogon flexuosus, Cymbopogon winterianus, Cymbopogon martini were analyzed by trapping the volatile organic compounds using solid-phase microextraction-gas chromatography-mass spectrometry and evaluated their antifungal activity against plant fungal pathogens like Fusarium oxysporum f. sp. cepa (Hypocreales: Nectriaceae) and Sclerotium oryzae Cattan (Magnaporthales: Magnaporthaceae). The major volatile organic constituents of C. flexuosus-citral (22.94%), neral (19.88%), camphene (8.37%), cyclohexene, 1-methyl-5-(1-methylethenyl-(R) (5.75%); C. winterianus-citronellal (42.47%), D-limonene (10.86%), geraniol (9.44%), citronellol (6.25%); C. martini-geraniol (43.80%), a-ocimene (10.75%), geranyl acetate (6.35%), 2,6-octadienal, 3,7-dimethyl-(E) (5.83%), were found in concentrations higher than 5.0% (calculated as % peak area of GC-MS analysis using a nonpolar column). In addition, the antifungal tests were also demonstrated that the essential oil of C. flexuosus C. winterianus and C. martini have excellent inhibitory effect against S. oryzae and F. oxysporum. The IC50 values of essential oils from C. flexuosus, C. winterianus and C. martini against at S. oryzae and F. oxysporum were 0.42, 0.41, 1.99 and 0.73, 2.02, 2.01 μL/plate respectively. The significant aroma may be the results of combined 30 volatile organic compounds from essential oils of Cymbopogon species which could be used as safe biocontrol agents to prevent stored product commodities from fungal pathogens.