CONICET | Buscador de Institutos y Recursos Humanos

American trypanosomiasis or Chagas disease is an endemic parasitosis caused by the protozoan Trypanosoma cruzi that affects 6 to 7 million people worldwide, mostly in Latin America and is responsible for more than 10000 deaths per year [1]. Benznidazole and nifurtimox are the only available drugs for its treatment. These antiparasitic drugs were developed half a century ago and present variable efficacy and fairly common side effects. Consequently, new therapeutic agents to treat this disease are urgently needed.As a result of our ongoing research on antiparasitic compounds from Stevia species, we have reported the trypanocidal activity of the organic extract of S. satureiifolia var. satureiifolia (Asteraceae) and the isolation of the active flavonoids eupatorin and 5-desmethylsinensetin [2]. Based on these results, we have continued the study of this extract in the search of other bioactive compounds. Dried aerial parts of S. satureiifolia var. satureiifolia were extracted by maceration with dichloromethane. Fractionation of this extract was performed by column chromatography using Silicagel and a gradient of dichloromethane:EtOAc. Seven fractions (FA to FG) were obtained. The purification of fraction D (FD), eluted with dichloromethane:EtOAc (2:1), afforded a precipitate (compound A). The purity of the compound was assessed by chromatographic techniques and the structure elucidation was performed by spectroscopic methods. The compound was identified as a germacranolide type sesquiterpene lactone. The in vitro activity of this sesquiterpene lactone against T. cruzi epimastigotes and amastigotes was tested, resulting in IC50 values of 1.75 and 6.33 µg/ml, respectively. Evaluation of the activity against trypomastigote forms of the parasite, which constitutes the predominant form in the acute phase of the disease, is currently in progress.