Chemical composition and antimicrobial activities of essential oil of Blumea megacephala.

Blumea megacephala essential oil, obtained through steam distillation of samples collected from the Shiwang Mountains in Guangxi Province, China, was analyzed using GC-FID and GC-MS. Among the 65 compounds identified in the oil, the main compounds were borneol (13.6 %), β-caryophyllene (9.56 %), germacrene D (9.09 %), sabinene (6.37 %), and α-humulene (4.78 %). Antimicrobial activity revealed that the essential oil (1000 μg/disc) has promising antimicrobial effects against several pathogens, giving satisfactory inhibition zone diameter values (21.5, 21.6, 23.4, 23.8, 21.9) and MIC values (125, 125, 62.5, 125, 125 µg/ml) against Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli), Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus), and yeast (Hansenula anomala). Antioxidant and antimicrobial activities were correlated with chemical composition.