Chemical constituents of the essential oil and antibacterial activity of Zingiber wrayi var. halabala

Zingiber wrayi var. halabala, a local herb from the Bala Forest in Narathiwat, was investigated for its chemical constituents and antibacterial activity. The essential oil was obtained by steam distillation of fresh rhizomes in 3.6 % yield. The GC-MS data indicated the presence of four compounds including trans-anethole, estragol, camphor and m-phenylphenol. Further quantitative analysis showed the essential oil to contain 96.8% w/w of trans-anethole. The oil, together with petroleum ether, dichloromethane and methanol extracts, were assayed for antibacterial activity. The essential oil, petroleum ether and dichloromethane extracts exhibited antibacterial activity against Bacillus substilis, Escherichia coli, Staphylococcus aureus and Sarcina sp. However, none of the extracts was active against Pseudomonas aeruginosa.