Antimicrobial Potential of Natural and Semi-Synthetic ent-Kaurane and ent-Pimarane Diterpenes against Clinically Isolated Gram-Positive Multidrug-Resistant Bacteria

In this work, a search for antimicrobial agents against multi-drug resistant (MDR) bacteria was undertaken. It involved two natural diterpenes of different basic skeletons, named ent-kaurenoic acid and ent-pimaradienoic acid, that were used as precursors to access 28 semi-synthetic derivatives that were also submitted to biological assays. All 30 substances were assayed against a set of seven clinically isolated MDR bacteria, including three Staphylococcus aureus strains. Results classified both natural compounds as promising bactericidal antimicrobial agents against these MDR bacteria, especi...