First-time isolation of flavonoids and cytotoxic potential of the Amazonian shrub Ptychopetalum olacoides Benth.

Resumo

: In the present study three flavonoids, 3-O-methylquercetin (1), 3,4'-O-dimethylquercetin (2) and 3,7-O-dimethylquercetin (3) were isolated and characterized for the first time from a methanol extract obtained from the species Ptychopetalum olacoides. The structures of compounds were identified by spectroscopic methods (1D-, 2D-NMR, MS and UV) and confirmed by comparison with the respective literature data. The cytotoxic effect of crude extract was evaluated in vitro against three human cancer cell lines. Results showed a mild cytotoxic activity (IC₅₀ = 45.16 µg/mL) against breast cancer (MCF-7), however crude extract did not exhibit any cytotoxic effect against normal cell human fibroblast (MRC-5).