ANTIBACTERIAL ACTIVITY OF THE HYDROALCOHOLIC EXTRACT OF PSEUDOBOMBAX MARGINATUM BARK AND ITS FRACTIONS
Antibacterial activity and possible mechanism of action of Copaifera duckei Dwyer
Aims: to determine the antibacterial activity of P. marginatum against bacteria of clinical interest and its possible mechanism of action. Methods and Results: the antibacterial activity of EHAPM and of BF was determined by Agar diffusion and dilution methods in which B. cereus was more susceptible, followed by Staph. aureus 29213 and 33591, with MICs corresponding to 0.5 mg ml-1 and 1.0 mg ml-1, respectively. Changes in the bacterial cell ultrastructure were shown through SDS-PAGE and TEM electrophoresis, suggesting that P. marginatum interferes in cell wall proteins of B. cereus as its possible mechanism of action. The main compound isolated was gallocatechin, identified by UV-Vis, IR, ESI-MS, HR-ESI-MS and NMR. Conclusions: HAEPMB and BF affected the bacterial cell wall with changes in the cytoplasmic membrane and content, causing growth inhibition or cell death. This activity is suggested to be attributed to the gallocatechin compound. Significance and Impact of the Study: It contributes to the understanding of the importance of native flora for pharmacological studies, stressing the need to preserve Brazilian ecosystems, since P. marginatum has shown an effective inhibitory activity against bacteria of clinical interest, which may be used as a therapeutic alternative to treat resistant and/or emerging microbial infections.