Essential oil of Algerian Eucalyptus citriodora: Chemical composition, antioxidant and antimicrobial activities

Abstract

This study was carried out to assess the chemical composition, antioxidant and antimicrobial activities of Eucalyptus citriodora essential oil growing in Algeria. The chemical composition of the oil was analyzed by GC and GC/MS and revealed the presence of 22 compounds which accounted for 97.13 % of the oil. The main compounds was Citronellal (69.77 %) followed by Citronellol (10.63 %) and Isopulegol (4.66 %). Antioxidant activity was evaluated by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The free radical scavenging activity of the oil was found to be inferior (IC50 values = 0.896 mg/ml) as compared to butylatedhydreoxytoluene (BHT), (IC50 value = 0.041 mg/ml). The antimicrobial activity of Eucalyptus citriodora essential oil against twelve bacteria and two yeasts was determined via both the disc diffusion method and the Disc volatilization method. Higher antimicrobial activity was observed in the liquid phase. The minimum inhibitory concentration (MIC) was found to vary from 0.6 to 20 µl/ml for bacteria while for yeasts it was equal to 1.25 µl/ml. The most sensitive strains were the Gram positive bacteria Staphylococcus epidermidis and the two yeasts while the most resistant bacterium was Pseudonomas aeruginosa. This is the first report on the antioxidant and antimicrobial properties of the essential oil of Eucalyptus citriodora growing in Algeria.

Keywords

• Antimicrobial activity
• Antioxidant activity
• Chemical composition
• Essential oil
• Eucalyptus citriodora Hook