Objective To establish the chemical profile, and to evaluate the antibacterial and modulatory activity of the ethanolic extracts of the stalk's inner bark and heartwood of Secondatia floribunda. Methods Quantification of total phenols and flavonoids was determined by the Folin-Ciocalteu method and aluminum chloride, respectively. Phenolic compounds were identified and quantified by HPLC-DAD (High Performance Liquid Chromatography-Diodearray Detector) and the Infrared Spectroscopy was performed using the measure by Attenuated Total Reflectance with Fourier Transform (ATR-FTIR). Antibacterial assays for determination of the Minimum Inhibitory Concentration (MIC) and modification of aminoglycosides were performed by microdilution. Results Infrared spectra showed similar characteristics, having among its main absorption bands hydroxyl group (OH). The antibacterial activity showed clinically significant results for the strains of Staphylococcus aureus and Escherichia coli. In modulation assay, synergic and antagonistic effect for both extracts was observed. Heartwood extract in combination with antibiotics showed a significant MIC reduction at 19.8% (P < 0.000 1)-79.3% (P < 0.01). Conclusions This study is the first report of chemical and biological information of Secondatia floribunda suggesting that it is clinically relevant source of a new antibacterial therapy, especially due to the presence of significant levels of phenolic compounds.

Objective To evaluate the trypanocidal, leishmanicidal and cytotoxic activity of Eugenia jambolana (E. jambolana) and Eugenia uniflora (E. uniflora) extracts and fractions. Methods The products were characterized by LC–MS. Antiparasitic assays were performed and cytotoxicity was evaluated in fibroblastos. In vitro assays were performed using spectrophotometric evaluation. All assays were performed in thrice. Results The results showed that the extracts and the tannic fraction from E. jambolana inhibited 100% of the epimastigote lines. The ethanolic extract was the most efficient in all concentrations tested against the three parasite strains. In the cytotoxicity assay the flavonoid fraction showed low toxicity. All E. uniflora samples showed cytotoxicity at the highest concentration tested, but the extract showed no toxic effect on the fibroblasts at the lowest concentration. The flavonoid and tannic fractions were more efficient against Leishmania braziliensis promastigotes compared to the extract. However, the extracts and the tannic fraction were more effective against Leishmania infantum strains. The effect on epimastigote cells was observed at all concentrations tested, with all E. uniflora samples. However, the samples were more effective at the highest concentration, where there was inhibition in 100% of the Trypanosoma cruzi strains. Conclusions The species E. jambolana and E. uniflora presented antiparasitic activity against all tested parasite strains, indicating that these species can serve as an alternative therapy as they were efficient in the tests performed. The E. uniflora extract and the E. jambolana flavonoid fraction presented a low cytotoxicity, opening the floor for new biological studies.

Objective To identify the main chemical classes of compounds from aqueous extract of Enterolobium contortisiliquum (E. contortisiliquum) seed bark and to evaluate its antibacterial activity, as well as its potential to increase the activity of antibiotics against strains of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. Methods Different classes of compounds in the aqueous extract of E. contortisiliquum were evaluated based on the visual changes in the coloration and the formation of precipitate after the addition of specific reagents. The antibacterial activity of the extract and its potential to increase of antibiotic activity of antibiotics drugs, gentamicin and norfloxacin was determined by using the microdilution method. Results Our results demonstrated that the following secondary metabolites were presented in E. contortisiliquum seed bark: flavones, flavonols, xanthones, flavononols, chalcones, aurones, flavones and catechins. The extract itself had very low antibacterial activity against all bacterial strains tested (MIC ≥ 1 024 μg/mL), but there was an increase in the antibiotic activity of gentamicin and norfloxacin when combined in the sub-inhibitory concentration (i.e., MIC/8). Conclusions Our data suggests that E. contortisiliquum seed bark may be an alternative source for new drugs with the potential to increase antibiotic activity against different strains of bacteria.