Compositions of volatile oil from Lagerstroemia indica L. were reported for the first time. Out of 114 components where 58, 63, 67 and 61 compounds were identified from the white, pink, mauve, carmine flower with yields of 0.92%, 1.15%, 1.12% and 1.08%, respectively. Main compounds of white flower were 2-methyl-cyclopentanone (9.41%), m-xylene (7.53%) while the pink, carmine flower contained octacosane (19.81% and 13.91%) and heneicosane (18.02% and 7.98%), respectively, and mauve flower contained cyclohexanone (8.13%), 1-octacosanol (7.87%). Only 23 components were common in four oils, representing 16.57-32.72% of the total oils. Composition classification of four oils included mainly alkanes, benzenes, ketones with 52.98-73.03% of the total oils. The results revealed the different characteristics in quality of these oils. The pink, mauve, carmine flower oils were found active against S. aureus and A. niger, P. aeruginosa and S. aureus, E. coli and B. subtilis with MIC value of 0.078 mg/mL.
Keywords: Lagerstroemia indica; antibacterial activity; chemical components; volatile oil.