Chemical Composition and Antifungal Activity of Essential Oils Extracted from Leaves of Eucalyptus Melliodora and Eucalyptus Anceps Grown in Rwanda

Essential oils were extracted from leaves of Eucalyptus melliodora and Eucalyptus anceps by steam distillation and chemically analysed using GC/MS.The main components obtained in both Eucalyptus species oils were, monoterpenes: 1,8-cineole (47.7 %, 33.49 %) and -pinene (7.8 %, 13.69 %) as dominant components, and sesquiterpenes: aromandrene (1 %, 18.01 %) and allo-aromandrene (1.5 %, 2.37 %), respectively. Caryophyllene (5.1 %) and bicyclogermacrene (4.6 %) were found only in E. melliodora. The antifungal efficacy of these essential oils was assessed against R. nigricans, A. flavus, A. niger, A. parasiticus, F. oxysporum and P. digitatum.The obtained results indicated that essential oil from E. melliodora was the most effective against all tested fungi with minimal inhibitory concentration (MIC) at 3.3 mg/mL for A. flavus. The anti-aflatoxin production test was conducted with essential oil from E. melliodora and A. flavus and A. parasiticus, as aflatoxins producers. The findings clearly showed that concentrations of 6 L/mL and 7 L/mL of the essential oil completely inhibited production of aflatoxins by A. parasiticus and A. flavus, respectively. However, further studies on this essential oil should be conducted to assure its standard use as antiaflatoxin agent.