Abstract
The essential oil obtained by hydrodistillation of the fresh leaves of Thottea ponmudiana was analyzed by gas chromatography and gas chromatography-mass spectrometry. Twenty-seven components comprising 87.4% of the leaf oil were identified. Among the identified constituents 14.8% were monoterpene hydrocarbons, 32.6% were sesquiterpene hydrocarbons and 40.0% oxygenated sesquiterpenes. The major component, pregeijerene B (E,E,E-1,7-dimethylcylododeca-1,4,7-triene) (25.8%) was isolated and identified by IR, GC/EIMS and 1H-NMR analyses. The other major components in the leaf oil were 8α-acetoxyelemol (21.6%) followed by terpinolene (10.1%), elemol (8.2%) and bulnesol (4.9%). The antibacterial activity of the oil was tested against both Gram-positive and Gram-negative bacteria. The oil showed significant activity against the Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis, in comparison with the standard, streptomycin.