Chemical Composition and In-vitro Antibacterial Activity of the Essential Oil of Nigerian Moringa oleifera Lam. Flowers
Aims: To investigate the chemical composition and antibacterial activity of essential oil isolated from flowers of Moringa oleifera (MO) grown in Western Nigeria. Methodology: Gas chromatography–mass spectrometry (GC-MS) analysis was carried out for identification and determination of the phytochemical constituents of the oil. Standard microbiological methods was also employed to evaluate the antibacterial activities of the oil. Results: GC-MS analysis revealed a total of twenty-five phytochemical constituents, with the major constituents found to be nonanal (17.3%), trans-geranyl geraniol (13.5%) and eicosane (12.3%), α- terpineol (7.2%), methyl palmitate (4.6%) and methyl octadec-9-enoate (4.1%). The antibacterial assay, using standard microbiological methods, showed that the oil had inhibitory effects against both Gram-positive (Bacillus cereus, Micrococcus luteus and Staphylococcus aureus) and Gramnegative (Escherichia coli and Pseudomonas aeruginosa) bacteria isolates. The minimum inhibitory concentrations (MICs) exhibited by the essential oil against test bacteria ranged between 1.25 mg/mL and > 5 mg/mL. Conclusion: Essential oil of Nigerian Moringa oleifera flowers contains biologically active ingredients and possess some level of antibacterial activity. The oil can be a good source of antibacterial agents.