Evaluation of triterpenes isolated from stems of <i>Pouteria macahensis</i> T. D. Penn. against <i>Proteus mirabilis</i>

Abstract

This article presents the results from a phytochemical study on an acetonic extract from the stems of <em>Pouteria macahensis </em>T.D. Penn., an endemic species of the Brazilian Atlantic Rainforest. By means of the bioautography method, this extract was evaluated against <em>Acinetobacter baummanii</em>, <em>Proteus mirabilis</em>, <em>Escherichia coli </em>and <em>Staphylococcus epidermidis </em>bacteria, of which only the <em>P. mirabilis </em>was found to be susceptible. The acetonic extract was chromatographed on a silica gel column, eluted with hexane and ethanol, producing 14 groups, allowing the isolation of the following compounds: friedelin, 3β-friedelinol and 3β-erythrodiol linoleate, arachidate and linolenate. Their structures were elucidated based on data of IR, 1H NMR, 13C NMR, including DEPT-135, HSQC and HMBC techniques. The minimum inhibitory concentrations of the compounds tested against <em>P. mirabilis </em>growth, were 500.0 μg mL-1 for friedelin and erythrodiol and 600.0 μg mL-1 for 3β-friedelinol and esterified 3β-erythrodiol. Based on these results, the potential of these compounds to inhibit the growth of this bacterium was confirmed.