| مستخلص: |
The chemical composition of essential oil in the leaves of Syzygium caryophyllatum collected during summer and winter seasons were analysed by GC-MS. The essential oil yield in summer and winter seasons were 0.2% and 0.35% respectively. Fifty five compounds representing 99.98% of the oil were identified in the winter season and 129 compounds in summer season with 100% of the leaves oil. In winter essential oil, a-cadinol (18.3%), myristicin (12.02%), d-cadinene (8.4%) and t-muurolol (6.65%) were the most prominent compounds followed by β-caryophyllene (5.33%), a-muurolol (5.11%), β-cis-ocimene (2.53%), β-elemen (2.52%) and calarene epoxide (2.31%), whereas in summer essential oil, the major chemical compounds were caryophyllene oxide (10.72%), a-pinene (10.55%), 4,8,13-duvatrene-1,3-diol (10.44%) and cadin-4-en-10-ol (8.27%) followed by β-gurjunenepoxide-(1) (5.93%), a-cadinol (4.6%), 3,5,9-trimethyl-deca-2,4,8-trien-1-ol (4.11%), β-pinene (2.77%) and cis-lanceol (2.66%). The isolated oils were tested for antibacterial activity carried out by disc diffusion method against six pathogenic bacteria viz., Bacillus cereus, B. licheniformis, Escherichia coli, Staphylococcus aureus, S. hominis and Aerococcus viridans. The disc diffusion and minimum inhibitory concentration of leaf essential oils of two seasons (summer and winter) exhibited potent inhibitory activity against A. Viridans (10 mm & 11.5 mm), B. Cereus (10 mm & 12.1 mm), and S. aureus (9.0 mm & 3.5 mm) respectively and the minimum inhibitory concentration (MIC) were A. viridans (5.625 & 22.5 µg/ml), B. cereus (22.5 & 5.625 µg/ml) and S. aureus (11.25 & 22.5 µg/ml) respectively. Leaf essential oils exhibited potent antibacterial activity against both gram positive and gram negative bacteria. Thus the results shows that S. caryophyllatum leaf essential oils exhibited promising antibacterial activity suggesting further research towards bio-prospecting of active compounds. [ABSTRACT FROM AUTHOR] |