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[en] Although the genus Duguetia is well known for producing alkaloids as chemical constituents, there are no reports of alkaloids identified in the species D. lanceolata. Thus, aiming to identify the chemical composition of this species, the dereplication of alkaloidic phase was performed by use of ultra-high performance liquid chromatography high resolution electrospray ionization tandem mass spectrometry (UHPLC-HR-ESI-MS/MS) and ¹H nuclear magnetic resonance (NMR). The chromatographic fractionation of the alkaloid extract from Duguetia lanceolata (Annonaceae) leaves afforded four fractions (I-IV) that were shown to be composed of aporphine alkaloids. ¹H NMR analysis and UHPLC-HR-ESI-MS/MS based dereplication allowed the identification of eight alkaloids: glaucine (1), norglaucine (2), isocorydine (3), N-methyllaurotetanine (4), oxoglaucine (5), liriodenine (6), lanuginosine (7), dehydroglaucine (8). Compounds 2, 3, 4, 6 and 7 were described for the first time in this species, while alkaloids 1, 5 and 8 are newly discovered in the genus Duguetia. Additionally, the antiparasitic activity of the four fractions was evaluated in vitro against Leishmania infantum and Trypanosoma cruzi. Fraction I, composed exclusively by 1, displayed activity against Leishmania infantum and Trypanosoma cruzi intracellular amastigotes, with half maximal inhibitory concentration (IC₅₀) values of 7.5 and 28.6 μg mL^-1, respectively. Fraction IV (constituted by 2, 3 and 4) showed activity against promastigotes of Leishmania infantum with IC50 value of 50.0 μg mL^-1, while fraction II (constituted by 5 and 6) showed activity against trypomastigotes of Trypanosoma cruzi, with IC₅₀ values of 83.0 μg mL^-1. This work showed that fragmentation in UHPLC-HR-ESI-MS/MS combined with ¹H NMR analysis of fractions is useful for identifying alkaloids in mixtures. Additionally, it was also demonstrated the potential of aporphine alkaloids from Duguetia lanceolata St.-Hil (Annonaceae) in the search for new drug candidates for neglected diseases. (author)

[en] MeOH extract from the leaves of Plectranthus barbatus Andrews (Lamiaceae), showed in vitro anti-trypanosomal activity. The bioassay-guided fractionation resulted in the isolation of a gallic acid derivative, identified as 1,2,3,4,6-penta-O-galloyl-β-D-glucose (PGG), after thorough NMR and MS spectral analysis. Finally, this compound was tested against trypomastigote forms of T. cruzi and displayed an EC₅₀ value of 67 μM, at least 6.6-fold more effective than the standard drug benznidazole. This is the first occurrence of PGG in the Plectranthus genus and the first anti-parasitic activity described for PGG in the literature (author)

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[en] In the present work five acetylene derivatives (1-5), including three unknowns (1, 3 and 4), were isolated from seeds of Porcelia macrocarpa (Annonaceae). The structures of isolated compounds were determined as docos-13-yn-21-enoic acid (1), 3-hydroxy-4-methylene-2-(eicos-11'-yn19'-enyl)but-2-enolide (2), 3-hydroxy-4-methylene-2-(octadec-9'-yn-17'-enyl)but-2-enolide (3), 3-hydroxy-4-methylene-2-(hexadec-7'-yn-15'-enyl)but-2-enolide (4), and (2S, 3R, 4R)-3-hydroxy4-methyl-2-(eicos-11'-yn-19'-enyl)butanolide (5) by analysis of nuclear magnetic resonance (NMR) and electrospray ionization high-resolution mass spectrometry (ESI-HRMS) data. Moreover, all isolated compounds demonstrated selectivity towards intracellular amastigotes of Leishmania (L.) infantum, especially 2-4 with 50% inhibitory concentration (IC₅₀) values of 9.2, 10.4 and 11.0 μM, respectively, indicating superior activity of that determined to positive control miltefosine (IC₅₀ of 17.8 μM). Furthermore, these compounds showed higher selectivity index (SI) in comparison with miltefosine. Since related acetylene fatty acid 1 displayed reduced antiparasitic potential (IC₅₀ of 48.5 μM), the obtained results suggested that the γ-lactone plays an important role in the antileishmanial activity. However, 2-4 exhibited cytotoxicity to mammalian NCTC cells (CC₅₀ ca. 80 μM), which could be a result of the presence of a conjugated carbonyl system in the lactone ring, since 5, the only acetogenin that presents the saturated ring, lacked mammalian cytotoxicity (CC₅₀ > 200 μM). (author)

[en] In the present work, dried aerial parts of Baccharis ligustrina (Asteraceae) were subjected to microwave assisted extraction (MAE) using aqueous solution of 1-butyl-3-methylimidazolium bromide (BMImBr) and the obtained extract was successively partitioned using hexane and EtOAc. Using reduced amounts of extracts and efficient chromatographic steps, four acyl C₆C₃ derivatives (n-hexacosyl ferulate, n-hexacosyl, n-octacosyl, and n-triacontyl p-coumarates) were obtained from hexane phase whereas two C₆C₃ acids (ferulic and p-coumaric) were obtained from EtOAc phase. Isolated phenylpropanoids were evaluated against amastigote forms of parasite Trypanosoma cruzi. As result, it was observed that p-coumaric and ferulic acids were inactives whereas alkyl derivatives displayed EC₅₀ values of 6.5 μmol L^-1 (n-octacosyl p-coumarate), 9.3 μmol L^-1 (n-triacontyl p-coumarate), 15.7 μmol L^-1 (n-hexacosyl p-coumarate), and 32.2 μmol L^-1 L^-1 (n-hexacosyl ferulate). All tested compounds displayed reduced toxicity against NCTC cells (CC₅₀ > 200 mmol L^-1). (author)

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