Original Articles: 2015 Vol: 7 Issue: 1
Chemical composition of Citrus aurantium L. leaves and zest essential oils, their antioxidant, antibacterial single and combined effects
This study aims to investigate the chemical composition, the single and the combined antibacterial effect of zest and leaves Citrus aurantium L essential oils. The identification of chemical compounds was made using chromatography analysis. Furthermore, the antibacterial effect of each essential oil was evaluated using disk-diffusion and the micro-dilution methods against four bacteria strains. While, the antioxidant activity was studied by the 1,1-diphenyl- 2-picrylhydrazyl (DPPH) radical scavenging assay. The checkerboard method was used to investigate the antibacterial combined effect of both essential oils. Results showed that the main components are linalyl 2- aminobenzoate (41.87%), β-linalool (32.99%) and α-terpineol (10.53%) for leaves essential oil. However, the major compound was limonene (98.11%) for zest essential oil. Regarding the DPPH radical scavenging activity, the zest essential oil showed higher activity than that of leaves. While, the single antibacterial effect of leaves essential oil was more effective. Moreover, the antibacterial combined effect of both essential oils was demonstrated a remarkable synergistic interaction at the optimal point (1/4 MIC + 1/128 MIC of leaves and zest essential oils respectively). Furthermore, no antagonistic effect was detected between these essential oils.