Molecular characterization and evaluation of antimicrobial activity of essential oils derived from Syzygium aromaticum

Abstract

Objective: This work is designed to study and evaluate the antibacterial potency of phytochemicals from Syzygium aromaticum (clove) contrary to foodborne pathogens. In the present research, the extract of S. aromaticum was characterized using thin-layer chromatography, gas chromatography–mass spectrometric (GC–MS), and Fourier-transform infrared (FT-IR). Methods: The extraction was done by hydrodistillation process and the existence of essential oils was detected by analytical and chromatographic techniques. The conformation of the presence of eugenol in the extracted sample was achieved with high-performance thin-layer chromatography in comparison with the standard. The extract was subjected to GC–MS and FT-IR for quantification and structure prediction, respectively. Antibacterial assay was performed with different concentration of clove extracts (25%, 50%, and 75%) against different foodborne pathogens such as Escherichia coli, Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Klebsiella oxytoca, and Staphylococcus epidermidis. ANOVA analysis with single factor was carried out to determine the significance of procured results. Results: The existence of higher concentration of eugenol along with caryophyllene and alpha-caryophyllene in the clove extract was manifested with GC–MS analysis. FT-IR analysis determined the major functional moieties and also confirmed the structure of bioactive compounds. After 24 h, the clove extract has shown to have antibacterial activity against all bacteria used in this study except for S. epidermidis. P value was found to be <0.05 which revealed the statistical significance of results. Conclusion: From this investigation, it is appraised that clove extract using the organic solvent dichloromethane has effective antibacterial property over foodborne pathogens. This study illustrates that organic compounds present in S. aromaticum could be an potent barrier against the microorganism tested and also could be used for the advancement in developing different drugs in Pharma industries.