Antibacterial Properties and Chemical Composition of Essential Oil from Aegle marmelos (L.) Corr. Leaves Growing in Bangladesh

Aegle marmelos is frequently used in Ayurveda medicine in countries of the Indian subcontinent like Bangladesh. The present study attempts to elucidate the antibacterial activity of A. marmelos leaves growing in Bangladesh (A. marmelos LBD) and to screen therapeutically important phytochemicals. The extracts of this plant's leaves prepared with six organic solvents were tested for their antibacterial activity against Bacillus subtilis IFO 3026, Escherichia coli IFO 3007, Klebsiella pneumoniae ATTC 10031, Proteus vulgaris MTTC 321, Pseudomonas denitrificans KACC 32026, Sarcinalutea IFO 3232, and Xanthomonas campestris IAM 1671. Inhibition of bacterial growth and the minimum inhibitory concentration (MIC) were assayed by the disk diffusion method. Essential oil of A. marmelos LBD was used for gas chromatographicmass spectrometric (GC-MS) analysis in order to determine its chemical composition. Among the six solvents, n-hexane and petroleum ether extracts showed a great potential of antibacterial activity against all the bacteria, with inhibition zones of 13.3 +/- 0.58 to 10 +/- 1.0 mm. whereas essential oil showed 12.33 +/- 1.53 mm to 9.33 +/- 0.58 mm inhibition zone. The MIC value was 32 mu gD ml for petroleum ether, dichloromethane, n-hexane extracts and 16 lD ml for essential oil of A. marmelos LBD. Eighteen chemical components were found after GC-MS analysis of essential oil of A. marmelos LBD. The major components of the essential oil are ledene oxide-(II) (18.16%); menthol, 12 -(butyn-3-one-1-yl), (1R, 2S, 5R) (7.04%); (-)-caryophyllene oxide (7.10%); and himachalol (6.15%). These phytochemicals were previously well known to have strong antibacterial activity, which explains why A. marmelos LBDis an effective antibacterial agent against various infectious diseases.