Abstract: | In current study, antibacterial compounds of ethyl acetate extract from white frangipani (Plumeria alba) stem bark were isolated and their antibacterial activities against Escherichia coli and Staphylococcus aureus were investigated. The plant extract was prepared by maceration of 500 g of dried stem bark P. alba in ethyl acetate. A total of 26 g (5.2 %) of crude plant extract was obtained. The fractionation was carried out by using vacuum liquid chromatography column (VLCC), resulting of five fractions with amount of 0.42 g, 0.36 g, 0.61 g, 0.99 g and 4.15 g for fraction A, B, C, D, and E, respectively. These fractions and crude extract were applied to the Kirby-Bauer method using discs with various concentrations of 0.5, 1.0, 2.0, and 3.0 %, to examine their antibacterial activities against E. coli and S. aureus. The fraction B was found to be the most active, showing average zone of inhibition, at 3.0 % concentration, of 12.4 mm and 15.6 mm to E. coli and S. aureus, respectively. The phytochemical analysis result of fraction B indicated terpenoids compounds. In this experiment, chloramphenicol was used as a positive control. |