Evaluation of leishmanicidal and trypanocidal activities of phenolic compounds from Calea uniflora Less.

The phytochemical study of Calea uniflora led to the isolation of nine phenolic compounds identified as noreugenin (1), ethyl caffeate (2), a mixture of butein (3) + orobol (4), alpha-hydroxy-butein (5), caffeic acid (6), butein 4'-O-glucopyranosyl (7), quercetin 3-O-glucopyranosyl (8) and 3,5-di-O-caffeoylquinic acid (9). The chemical identity of the isolates was established on the basis of NMR and physical data. The chemical shifts of 5 and 7 have been reassigned and all the isolates were tested against Leishmania amazonensis and Trypanosoma cruzi amastigotes. None of the metabolites showed promising leishmanicidal activity. However, 2 and the mixture of 3 and 4 demonstrated interesting trypanocidal effect with IC50 values of 18.27 and 26.53 mu M, respectively. Besides, these compounds did not present cytotoxic effect towards THP-1 cells, and compound 2 was 3.5-fold more selective than the mixture of 3 + 4.