First-time Isolation of Flavonoids and Cytotoxic Potential of the Amazonian Shrub Ptychopetalum olacoides Benth

Abstract

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. The results showed a mild cytotoxic activity (IC50 = 45.16 mu g/mL) against breast cancer (MCF-7). However, crude extract did not exhibit any cytotoxic effect against normal cell human fibroblast (MRC-5).