Brosimacutins J - M, Four New Flavonoids fromBrosimum acutifoliumand their Cytotoxic Activity

Four new flavonoids, brosimacutins J-M (1-4), were isolated from the bark of Brosimum acutifolium Huber together with a known flavan, brosimine A (5). The structures of compounds 1 4 were elucidated by spectroscopic means. 27 constituents of this plant including compounds 1-5 were evaluated for their cytotoxic activity against murine leukemia P388 cells. Although no compounds tested had any reversal effect on vincristine resistance, brocimacutins J-M (1-4) were cytotoxic to vincristine-resistant P388 cells (IC50 4.4-19 mu g/mL).