The phytochemical investigation of the hexane extract which was obtained from the leaves of Xylopia laevigata (Annonaceae) produced six terpenes. Among these, five diterpenes named abieta-7,13-dien-3-one, ent-7β-acetoxy-16β-hydroxy-kaurane, 4-epi-cupressic acid, powerol, and labdorffianic acid B, and one oxygenated sesquiterpene, spathulenol. This is the first time these isolated diterpenes from X. laevigata have been described. The different structures belong to the abietane, kaurane, and labdane diterpenoids, and are indicative of the chemical diversity found in X. laevigata. Moreover, the diterpene ent-7β-acetoxy-16β-hydroxy-kaurane is reported herein for the first time as a natural product, and 4-epi-cupressic acid, powerol, and labdorffianic acid B are reported for the first time in the Annonaceae family. The structures of the isolated compounds were established by extensive analyses using 1D and 2D NMR spectroscopy in combination with MS. The cytotoxic activities of compounds abieta-7,13-dien-3-one, spathulenol, 4-epi-cupressic acid, and powerol were evaluated against tumor and non-tumor cell lines, in which spathulenol was found to be the most active, mainly against K562 with an IC50 value of 17.20 μmol L-1.

The phytochemical investigation of the alkaloid-rich fraction obtained from the leaves of Guatteria pogonopus Mart. (Annonaceae) allowed the isolation and identification for the first time in this species of: (+)-nornuciferine (1), a mixture of 1 and (+)-anonaine (2), (+)-isocorydine (3), (+)-nuciferine (4), (+)-roemerine (5), (-)-tetrahydropseudocolumbamine (6), a mixture of 6, liriodenine (9) and lysicamine (10), a mixture of 1,2,9-trimethoxy-10-hydroxyaporphine (7) and bulbocapnine (8), 9, 10, and (+)-N-methyllindicarpine (11). Compounds 6, 7, 8, and 11 have not been previously reported in the family Annonaceae. Furthermore, the formerly synthetic 1,2,9-trimethoxyaporfin-10-ol (7) is described for the first time as a natural aporphine alkaloid herein. The chemical structures were established by 1D and 2D NMR as well as in comparison with data previously reported in the literature. The cytotoxic activity of the alkaloids was evaluated against tumor (B16-F10, HepG2, HL-60, and K562) and non-tumor (PBMC) cell lines. Alkaloid 1 presented significant activity against HepG2 cell lines with IC50 of 9.60 µmol L-1 while the mixture of 6, 9 and 10 displayed strong cytotoxic activity against HL-60 and K562 cell lines with IC50 values of 3.41 an 8.50 µmol L-1, respectively.

AbstractAtemoya is an interspecific annonaceous hybrid between Annona cherimola Mill. and Annona squamosa L. Its phytochemical investigation led to seven alkaloids, including two aporphine (anonaine and asimilobine), three oxoaporphine (lanuginosine, liriodenine and lysicamine) and two proaporphine (pronuciferine and stepharine). These alkaloids were identified by a series of spectrometric methods, mainly MS and NMR (1D and 2D), as well as by comparison with literature data. Our findings showed that this species is an important source of aporphine alkaloids and have high relationship with other Annona species.