Endemic in 21 countries, Chagas disease, also known as American Trypanosomiasis, is a neglected tropical disease (NTD) caused by the protozoan parasite Trypanosoma cruzi. The available drugs for the treatment of this disease, benznidazole and nifurtimox, are outdated and display severe side effects. Thus, the discovery of new drugs is crucial. Based on our continuous studies aiming towards the discovery of natural products with anti-T. cruzi potential, the MeOH extract from aerial parts of Baccharis sphenophylla Dusén ex. Malme (Asteraceae) displayed activity against this parasite and was subjected to high-performance countercurrent chromatography (HPCCC), to obtain one unreported syn-labdane diterpene — sphenophyllol (1) — as well as the known compounds gaudichaudol C (2), ent-kaurenoic acid (3), hispidulin (4), eupafolin (5), and one mixture of di-O-caffeoylquinic acids (6–8). Compounds 1–8 were characterized by analysis of nuclear magnetic resonance (NMR) and mass spectrometry (MS) data. When tested against trypomastigote forms, isolated labdane diterpenes 1 and 2 displayed potent activity, with EC₅₀ values of 20.1 μM and 2.9 μM, respectively. The mixture of chlorogenic acids 6–8, as well as the isolated flavones 4 and 5, showed significant activity against the clinically relevant amastigotes, with EC₅₀ values of 24.9, 12.8, and 2.7 μM, respectively. Nonetheless, tested compounds 1–8 displayed no cytotoxicity against mammalian cells (CC₅₀ > 200 μM). These results demonstrate the application of HPCCC as an important tool to isolate bioactive compounds from natural sources, including the antitrypanosomal extract from B. sphenophylla, allowing for the development of novel strategic molecular prototypes against tropical neglected diseases.

The present study investigated the chemical composition and antileishmanial activity of Vernonanthura polyanthes essential oils over a two-year monitoring period (monthly collection from January/2023 to December/2024). The oils exhibited a high concentration of hydrocarbon sesquiterpenes, primarily germacrene D, β-caryophyllene, α-humulene, and bicyclogermacrene, whereas the levels of monoterpenes and oxygenated sesquiterpenes fluctuated seasonally. Activity against promastigotes of Leishmania (L.) infantum was strongly dependent on the essential oil chemical profile, with consistently low EC₅₀ values seen in months with a higher content of hydrocarbon sesquiterpenes. However, significant increases in oxygenated sesquiterpenes at the end of 2024 were accompanied by a reduction in potency. Cytotoxicity against NCTC cells remained low in most samples (CC₅₀ > 200 µg/mL). Multivariate statistical analysis was applied to investigate the relationship between the chemical composition of studied essential oils and their antileishmanial activity. Partial Least Squares (PLS) modeling based on key volatile markers (VIP > 1.0) revealed a significant correlation between constituent profiles and biological potency, explaining 61% of the activity variance (R² = 0.61). Regression coefficients identified β-caryophyllene and β-pinene as major contributors to enhanced activity, while β-bourbonene was associated with reduced potency. Seasonal evaluation showed that β-caryophyllene provides stable baseline activity, whereas peaks in β-pinene correspond to increased potency, suggesting a positive correlation associated with enhanced potency between these constituents. Integrated EC₅₀ and CC₅₀ models further demonstrated that β-pinene and β-caryophyllene combine desirable features of strong activity and low cytotoxicity. These findings clarify the metabolic drivers of seasonal bioactivity in V. polyanthes and highlight key biomarkers that may guide future pharmacological and biotechnological applications.