Purification of compounds responsible for the antimicrobial activity of plant extracts of Cariniana legalis

The study investigated the antimicrobial potential of leaf extracts of Cariniana legalis (Pink Jequitibá), a plant of the Lecythidaceae family, aiming at the discovery of new compounds with antibacterial activity. The leaves were subjected to the extraction process using different polar solvents, with the hydroalcoholic extract showing the greatest antimicrobial activity. The extract was fractionated by liquid-liquid separation and silica chromatography, and the fractions were evaluated for their antimicrobial capacity by inhibition halo in Escherichia coli, Staphylococcus aureus and Ralstonia solanacearum. The liquid-liquid separation fraction obtained with ethyl acetate showed the best result and was subjected to chromatographic separation. The obtained fractions were standardized, and the results of this step indicated potential to inhibit bacterial growth and biofilm formation. The presence of methylated esters derived from organic acids could be identified by GC/MS with 85% certainty in alignment with the mass spectrometry library. The results suggest that Cariniana legalis is a promising source of antimicrobial compounds with polar characteristics as biosurfactants.