Abstract: Objective: To study the chemical constituents and antimicrobial activity of volatile oil from the nutlets of Clausena anisum-olenas. Methods: The volatile oil was extracted by steam distillation and then analyzed by GC-MS. The disk diffusion method was used for antimicrobial activity analysis. Results: The major chemical compositions identified in nutlet oil from the plant were 4-methoxy-6-(2-propenyl)-1,3- benzodioxole (47.07%), 1,2,3-trimethoxy-5-(2-propenyl)- benzene (8.25%), 2,6- dimethoxy-4-(2-propenyl)-pheno (7.17%), n-hexadecanoic acid (7.05%) and tricosane (4.95%). The volatile oil had strong inhibitory effect against Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Bacillus cereus with minimal inhibitory concentration (MIC) of 0.35, 0.09, 0.17 mg/disc and 0.17 mg/disc, respectively.

Key words: Clausena anisum-olens, volatile oil, chemical constituents, antimicrobial activity