Bioassay-Guided Fractionation of Anti-Leishmania Amazonensis Extracts from Ampelozizyphus Amazonicus by High-Speed...

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, this 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, with EW showing the greatest promise. High-speed countercurrent chromatography (HSCCC) combined with mass spectrometry (MS) off-line detection was employed for the bioassay-guided fractionation of EAEB and EAEW using HEMWat as a solvent system. These extracts showed to be rich in saponins and triterpenes, besides the presence of glycosylated flavonoids recently reported as minor compounds. The fractions obtained from HSCCC showed high toxicity. However, this technique proved effective in obtaining fractions with a high purity level, 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.