A New Furanoheliangolide Sesquiterpene Lactone from Calea pinnatifida (R. Br.) Less. (Asteraceae) and Evaluation of Its Trypanocidal and Leishmanicidal Activities

Calea pinnatifida (R. Br.) Less. is commonly known in Brazil as "cipo-cruz", "quebra-tudo" or "aruca". This species is employed in folk medicine as giardicidal, amoebicidal and to treat digestive disorders. The present paper describes the isolation and structure determination of a new furanoheliangolide sesquiterpene lactone named 11,13-dihydroxy-calaxin, in addition to seven known compounds: ethyl caffeate, vanillin, 12-hydroxy-encecalin, phytol, 3,4-di-O-caffeoylquinic acid, 3,5-di-O-caffeoylquinic acid and 4,5-di-O-caffeoylquinic acid from the ethanol extract of C. pinnatifida leaves. Additionally, 11,13-dihydroxy-calaxin, vanillin, 12-hydroxy-encecalin, phytol, 3,4-di-O-caffeoylquinic acid, 4,5-di-O-caffeoylquinic acid and the mixture of 3,4-di-O-caffeoylquinic, 3,5-di-O-caffeoylquinic and 4,5-di-O-caffeoylquinic acids were assayed against the amastigote forms of Leishmania amazonensis and Trypanosoma cruzi, and the sesquiterpene lactone 11,13-dihydroxy-calaxin exhibited a promising trypanocidal and leishmanicidal activity, displaying IC50 values of 5.27 and 8.30 mu M, respectively.