Chemical Characterization of Clove (Syzygium aromaticum) Bud Essential Oil and Microbicidal Activity against Isolated Clinical Strains

Abstract

Clove (Syzygium aromaticum) is one of the most valuable spices that had been used for centuries as food preservative and for many medicinal purposes. So far, the studies on utilization of clove oil as an essential oil are still limited. In this study Syzygium aromaticum (clove) essential oil was isolated from buds by hydro-distillation process and characterized by GC-MS. Micorbiocidal and antioxidant potential was evaluated by agar well diffusion assay, DPPH assay and ferrous chelation potential assay. Major components identified were Eugenol (82.414%), Eugenyl acetate (15.196%), Beta caryophyllene (1.919%) and Alpha-caryophyllene (0.472%). Antimicrobial activity was evaluated against reference strains and clove oil exhibited potential antifungal activity against Bipolaris specifera, Curvularia lunata and Alternaria alternata with IC50 value 0.014 mg/ml, 0.015 mg/ml and 0.014 mg/ml (w/v), respectively and antibacterial activity against Bacillus cereus (24mm), Bacillus subtilis (6mm), Micrococcus luteus (15mm), Alcalygens denitrificans (13mm), Pseudomonas alcaligens (9mm) and Enterococcus fecalis (12mm) but no activity was observed against Camphylobacter coli and Klebsiella pneumonia. Further, microbiocidal properties against clinically isolated bacterial strains were also analyzed and significant activity with MIC value of 0.125 to 0.625 mg/ml for Escherichia coli and 0.5±0.23 mg/ml (w/v) for Staphylococcus aureus was observed. Simultaneously, potential free radical scavenging 1.590±0.07 mg/ml (w/v) and ferrous chelation potential 11±1.2% was also noted. In conclusion, clove essential oil can be considered as a potential antimicrobial agent for food and pharmaceutical industries.