Cytotoxic effects of mammea type coumarins from Calophyllum brasiliense.

Calophyllum brasiliense (Clusiaceae) is a big tree from the Tropical Rain Forests of the American continent. The organic extracts from the leaves yielded coumarins of the mammea type: mammea A/BA, A/BB, B/BA, B/BB, C/OA, C/OB, B/BA cyclo F, B/BB cyclo F, and isomammeigin. The triterpenoids friedelin and canophyllol, as well as the biflavonoid amentoflavone, protocatechuic and shikimic acids, were also obtained. Most of the isolated compounds were tested in vitro against K562, U251, and PC3 human tumor cell lines. The coumarins were cytotoxic against the three cell lines, the highest activity was shown by mammea A/BA (IC50 = 0.04 to 0.59 microM). The mixtures of mammea A/BA + A/BB, mammea B/BA + B/BB and mammea C/OA + C/OB were also highly active (IC50 < 4.05 microM). Friedelin was cytotoxic only against PC3, and U251 lines. Inhibition of HIV-1 reverse transcriptase was also assayed in vitro; however, none of the tested compounds (250 microM) prevented the activity of this enzyme. Most of the isolated compounds were also inactive against fourteen bacterial strains; however mammea A/BA + A/BB, and mammea C/OA + C/OB inhibited the growth of Staphylococcus aureus, S. epidermidis and Bacillus subtilis.