Abstract
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.
Highlights
Annonaceae is composed of 135 genera and 2500 species.[1]
Three singlets at 6.71, 6.91 and 7.99 can be attributed to aromatic hydrogens H-3, H-8 and H-11, respectively, (Figure S1, SI section). This data made the identification of glaucine (1) (C21H25NO4) [M + H]+ 356.1861 (0.0 ppm) possible after comparison of 1H nuclear magnetic resonance (NMR) data with those reported in literature.[25]
The 1H NMR spectrum of this mixture showed duplicated characteristic signals of oxoaporphine alkaloids, including two singlets at dH 7.39/7.51, attributed to H-3, besides aromatic hydrogens with two doublets at dH 7.74/7.79 and two at dH 8.87/8.92 that could be attributed to H-4 and H-5, respectively, of two different alkaloids (Figure S5, SI section)
Summary
Annonaceae is composed of 135 genera and 2500 species.[1] Among these genera, 34 can be found in South America and 29 occur in Brazil, including Duguetia.[2] The main chemical compounds isolated from Annonaceae are alkaloids, diterpenes, flavonoids, steroids and acetogenins.[3,4,5,6]. Duguetia lanceolata St.-Hil is popularly known as “pindaiva” or “ateira-da-mata”.7. This species occurs in Brazil in the states of São Paulo, Minas Gerais, Mato Grosso do Sul, Paraná, Rio Grande do Sul and Santa Catarina.[8] Until now, there are few chemical reports about D. lanceolata in literature, and some studies describe identification of trans-asarone, 2,4,5-trymethoxystirene, stigmasterol, sitosterol and campesterol from its leaves.[9,10] the chemical composition of its essential
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
