Xantonas isoladas do caule e da raiz de Kielmeyera coriacea (Calophyllaceae) e avaliação de suas atividades antimicrobianas.

Abstract

This paper describes the isolation of five xanthones present in the roots and stem extract of Kielmeyera coriacea Mart. (Calophyllaceae) and the evaluation of the antimicrobial activity of these xanthones. The specimens were collected in Parque do Cercado in Chapada Diamantina - Bahia. The stem and roots of the plant were submitted separately to maceration in hexane and ethyl acetate, generating the respective hexanic and ethyl acetate extracts. The extracts, in turn, were subjected to several chromatographic processes, and an unpublished xanthone was obtained from the fractions of the ethyl acetate extract of the roots, in addition to an unpublished xanthone and three already known, having been obtained from the ethyl acetate extract from the stem. The substances were identified using spectrometric methods, such as one-dimensional (1H and 13C) and two-dimensional (gHMBC and gHSQC) Nuclear Magnetic Resonance and mass spectrometry. The antimicrobial activity of xanthones was evaluated by the broth dilution method, and one of the already known xanthones showed activity against Micrococcus luteus, Staphylococcus aureus, Bacillus cereus, Bacillus subtilis and Candida albicans and one of the new xanthones showed activity against Micrococcus luteus. As perspectives, there is the publication of unpublished xanthones and antimicrobial activities that still do not appear in the literature.