One new iridoid named aureanin (1) was isolated from the leaves of Tabebuia aurea (Silva Manso) Benth. & Hook.f. ex S.Moore, together with eight known compounds, isoquercetin (2), astragalin (3), callicoside B (4), amphipaniculoside E (5), rehmaglutin D (6), quercetin-3-sambubioside (7), rutin (8), kaempferol-3-O-rutinoside (9). The structures of the isolated compounds were elucidated and confirmed by spectroscopic methods, including 1 D and 2 D NMR experiments, as well as HR-ESI-MS. Compounds 1-9 were evaluated for their in vitro cytotoxic activity against three human cancer cell lines (A549, HepG2, and MCF-7) and Leishmania major. Compound 4 showed activity against A549 (IC50: 36.8 ± 1.5 μg/mL, etoposide (positive control): 28.1 ± 4.2 μg/mL), however, none of the compounds were active against L. major.
Keywords: Bignoniaceae; Tabebuia aurea (Silva Manso) Benth. & Hook.f. ex S.Moore; antileishmania; aureanin; cytotoxicity; iridoid.