Antifungal Activity of the Essential Oils of Nine Zingiberaceae Species

The rhizome oils of nine Zingiberaceae species [Zingiber officinale Rosc., Z. cassumunar Roxb., Z. zerumbet Smith, Curcuma aeruginosa Roxb., C. mangga Valeton and van Zyp, C. xanthorrhiza Roxb., Kaempferia galanga Linn., Alpinia galanga Swartz and Boesenbergia pandurata (Roxb.) Schlecht] were investigated for their antifungal activities against five dermatophytes (Trichophyton mentagrophytes, T. rubrum, Microsporum canis, M. nanum and Epidermophyton floccosum), three filamentous fungi (Aspergillus niger, A. fumigatus and Mucor sp.) and five strains of yeast (Saccharomyces cerevisiae, Cryptococcus neoformans, Candida albicans, Ca. tropicalis and Torulopsis glabrata). The antifungal testing was carried out by using the broth microdilution and the disc gel diffusion methods. Amongst the essential oils studied, only the oil of B. pandurata was effective against all the fungi, exhibiting the lowest MIC values of 0.63µgµl -1 to Mucor sp., 1.25µgµl -1 to both A. niger and A. fumigatus, and 2.5µgµl -1 to both T. rubrum and E. floccosum, and the highest inhibition zone diameter of 20.6mm against S. cerevisiae. The essential oil of K. galanga showed selective toxicity against A. fumigatus with a MIC value of 0.63µgµl -1, while the essential oils of Z. officinale and Z. cassumunar exhibited high activity against the yeasts (11.7-15.7mm). The chemical composition of the active essential oils was investigated by GC and GC-MS.