Bioassay-guided Fractionation of Anti-Leishmania amazonensisExtracts from Ampelozizyphus amazonicus by High-speed Countercurrent Chromatography.

Abstract

Ampelozizyphus amazonicus Ducke, known as "saracura-mirá" in the Amazon rainforest, is valued for its traditional use in malaria prevention and treatment. The plant's roots and bark are employed for these purposes, while the wood is often overlooked. Given the global importance of leishmaniasis, research focused on A. amazonicus anti-Leishmania amazonensis potential. The ethyl acetate extract from the bark (EAEB) exhibited the most effective inhibition of intracellular amastigote growth with IC50 7.0 µg.mL-1 but showed high toxicity (CC50 9.0 µg.mL-1). The wood ethanol (EW) and ethyl acetate (EAEW) extracts demonstrated promising results against L. amazonensis with IC50 15.8 µg.mL-1 and 10.0 µg.mL-1, CC50 50.5 µg.mL-1 and 22.7 µg.mL-1, respectively. High-speed countercurrent chromatography combined with mass spectrometry off-line detection was employed for the bioassay-guided fractionation of EAEB and EAEW using HEMWat as solvent system. These extracts showed to be rich in saponins and triterpenes, besides minor glycosylated flavonoids. HSCCC was effective in obtaining high purity fractions, leading to the identification of a di-glycosylated triterpene saponin from EAEB, and melaleucic acid from EAEW. These findings highlight A. amazonicus as a potential source for developing new therapeutic alternatives for leishmaniasis and HSCCC as a technique enabling better separation efficiency of complex saponin matrices.