Calea uniflora Less., commonly known in Brazil as “erva-de-lagarto” and “arnica-da-praia”, is used in folk medicine to treat internal and external bruises and as anti-inflammatory. However, despite the popular use there is a lack of information in terms of isolation and biological evaluation of its secondary metabolites. Thus, the aims of this study were to identify and characterize compounds of C. uniflora leaves with trypanocidal and leishmanicidal potential. METHODS: Structures of compounds were determined by HRESIMS spectra, and 1D and 2D NMR spectra. Then, they were tested for in vitro leishmanicidal and trypanocidal activities against Leishmania amazonensis and Trypanosoma cruzi intracellular amastigotes, respectively. RESULTS: Four germacranolide-type sesquiterpene lactones were isolated and characterized from dichloromethane fraction: 2α-hydroxy-8β-2’,3’,5’-trihydroxy-angeloyloxycostunolide (1), desacetyleupaserrin (2), 2α-hydroxy-8β-3’-hydroxy-2’,5’-epoxyangeloyloxycostunolide (3) and ovatifolin (4). All compounds are described herein for the first time for C. uniflora and Calea genus. Lactones 1, 2 and 4 demonstrated weak or no inhibition of the T. cruzi amastigotes, whereas compound 3 revealed a moderate effect (36.8%). Regarding the leishmanicidal activity, 4 exhibited a 59.9% inhibitory effect on the growth of L. amazonensis. CONCLUSION: None of the isolated compounds presented promising trypanocidal effect and 4 was the most active compound against L. amazonensis amastigotes.

Calea pinnatifida (R. Br.) Less., Asteraceae, is popularly known as “quebra-tudo”, “cipó-cruz” or “aruca”. This species is used in the folk medicine for the treatment of stomach pain, giardiasis and amoebiasis. The aim of this study was to isolate and identify chromenes from leaves of C. pinnatifida and evaluate their leishmanicidal activity. A fraction from leaves of C. pinnatifida was analyzed for their chemical constituents, resulting in the isolation and characterization of four known chromenes: 6-acetyl-7-hydroxy-2,2-dimethylchromene (1), 6-acetyl-7-methoxy-2,2-dimethylchromene (2), 6-(1-hydroxyethyl)-7-methoxy-2,2-dimethylchromene (3) and 6-(1-ethoxyethyl)-7-methoxy-2,2-dimethylchromene (4). Structure identification of isolated compounds involved analysis of spectral data of 1D and 2D-NMR. The isolated compounds are here reported for the first time in C. pinnatifida, and the chromenes 1 and 3 show a moderate leishmanicidal activity.