Abstract

Steam distillation of the dry flower buds of Syzigium aromaticum (clove) yielded 7% (w/w) of the pure light yellow oil. Gas chromatography-mass spectrometry (GC-MS) analysis of the oil revealed that the components were eugenol, caryophyllene, eugenol acetate and alpha-humelene, with eugenol being the main component. The antimicrobial sensitivity of the volatile oil against some Gram-negative bacteria (Escherichia coli ATCC 35218, Escherichia coli, Klebsiella pneumoniae, Salmonella paratyphi, Citrobacter spp. and Enterobacter cloacae), a Gram-positive bacterium (Staphylococcus aureus ATCC 25923), and a fungus (Candida albicans) showed a broad spectrum of activity. The minimum inhibitory concentration (MIC) was determined for each organism as 2.4, 1.6, 0.27, 0.016, 0.23, 1.63, 0.73 and 0.067 mg/ml for S. aureus ATTC 25923, E. cloacae, S. paratyphi, K. pneumoniae, E. coli ATTC 35218, E. coli, Citrobacter spp. and C. albicans, respectively. Antioxidant screening of clove oil with 2,2-diphenyl-picryl-hydrazyl radical (DPPH) was positive, indicating the presence of free radical scavenging molecules which can be attributed to the presence of eugenol, a phenolic compound.

Key words: Syzigium aromaticum, clove oil, antimicrobial, antifungal, Gram-negative bacteria, Gram-positive bacteria, Gas chromatography, mass spectrometry.