The isolation of a triterpene and four diterpenes of the cassano type was performed from the fractionation of the AcOEt / CH3OH extract of mature leaves of Myrospermum frutescens. All the isolated compounds were evaluated to determine their antibacterial potential against Gram-positive and Gram-negative bacteria by the diffusion-disk antibiogram method. Among the compounds tested, it was observed that the compound 6?,13-dihidroxi-18-acetoxi-cassano-15,16-diene (4) showed higher activity against Staph. aureus with inhibition halos of 15, 16 and 17 mm for the loads of 25, 50 and 75 ?g, respectively. The values ??registered in relation to the sensitivity ranges for the Gentamicin control indicated that this bacterium shows sensitivity to this compound. Compounds Estigmasterol (1), 6?-hidroxi-18-acetoxycassano-13,15-diene (2), 6?,-18-dihidroxicassano-13,15-dieno (3), and 6?,18,17-trihidroxicassano-13,15-dieno (5), showed moderate activity, but lower compared to the positive controls used (Ampicillin and Gentamicin) in this trial.