Lívia Macedo Dutra

Chemical composition of the essential oils of Annona pickelii and Annona salzmannii (Annonaceae), and their antitumour and trypanocidal activities

The essential oils from the leaves of Annona pickelii and Annona salzmannii (Annonaceae) were obtained by hydrodistillation using a Clevenger apparatus, and analysed by GC-MS and GC-FID. A total of 21 compounds were identified in the essential oil of A. pickelii and 23 in that of A. salzmannii; sesquiterpenes predominated in both essential oils. Bicyclogermacrene (38.0%), (E)-caryophyllene (27.8%), α-copaene (6.9%) and α-humulene (4.0%) were the main components of A. pickelii, while δ-cadinene (22.6%), (E)-caryophyllene (21.4%), α-copaene (13.3%), bicyclogermacrene (11.3%) and germacrene D (6.9%) were the main components of A. salzmannii. The biological activities of the essential oils against Trypanosoma cruzi epimastigote forms and cytotoxicity against tumour cell lines (antitumour) were investigated. The essential oils showed potent trypanocidal and antitumour activities with values of IC50 lower than 100 µg mL−1.

ent-Kaurane diterpenes from the stem bark of Annona vepretorum (Annonaceae) and cytotoxic evaluation.

This work describes a novel ent-kaurane diterpene, ent-3β-hydroxy-kaur-16-en-19-al along with five known ent-kaurane diterpenes, ent-3β,19-dihydroxy-kaur-16-eno, ent-3β-hydroxy-kaur-16-eno, ent-3β-acetoxy-kaur-16-eno, ent-3β-hydroxy-kaurenoic acid and kaurenoic acid, as well as caryophyllene oxide, humulene epoxide II, β-sitosterol, stigmasterol and campesterol from the stem bark of Annona vepretorum Mart. (Annonaceae). Cytotoxic activities towards tumor B16-F10, HepG2, K562 and HL60 and non-tumor PBMC cell lines were evaluated for ent-kaurane diterpenes. Among them, ent-3β-hydroxy-kaur-16-en-19-al was the most active compound with higher cytotoxic effect over K562 cell line (IC50 of 2.49 μg/mL) and lower over B16-F10 cell line (IC50 of 21.02 μg/mL).

Cytotoxic Alkaloids from the Stem of Xylopia laevigata

Xylopia laevigata (Annonaceae), known locally as “meiú” or “pindaíba”, is widely used in folk medicine in Northeastern Brazil. In the present work, we performed phytochemical analyses of the stem of X. laevigata, which led to the isolation of 19 alkaloids: (−)-roemerine, (+)-anonaine, lanuginosine, (+)-glaucine, (+)-xylopine, oxoglaucine, (+)-norglaucine, asimilobine, (−)-xylopinine, (+)-norpurpureine, (+)-N-methyllaurotetanine, (+)-norpredicentrine, (+)-discretine, (+)-calycinine, (+)-laurotetanine, (+)-reticuline, (−)-corytenchine, (+)-discretamine and (+)-flavinantine. The in vitro cytotoxic activity toward the tumor cell lines B16-F10 (mouse melanoma), HepG2 (human hepatocellular carcinoma), K562 (human chronic myelocytic leukemia) and HL-60 (human promyelocytic leukemia) and non-tumor peripheral blood mononuclear cells (PBMCs) was tested using the Alamar Blue assay. Lanuginosine, (+)-xylopine and (+)-norglaucine had the highest cytotoxic activity. Additionally, the pro-apoptotic effects of lanuginosine and (+)-xylopine were investigated in HepG2 cells using light and fluorescence microscopies and flow cytometry-based assays. Cell morphology consistent with apoptosis and a marked phosphatidylserine externalization were observed in lanuginosine- and (+)-xylopine-treated cells, suggesting induction of apoptotic cell death. In addition, (+)-xylopine treatment caused G2/M cell cycle arrest in HepG2 cells. These data suggest that X. laevigata is a potential source for cytotoxic alkaloids.

ALKALOIDS FROM LEAVES OF Guatteria pogonopus (ANNONACEAE) AND THEIR CYTOTOXICITIES

CNPq, CAPES, FINEP, FAPEAM, Fundacao Araucaria, FAPITEC/SE, UFAM, UFS, and UFPR for financial support and fellowship.