New cytotoxic lupane triterpenoids from the twigs of Coussarea paniculata

Bioassay-guided fractionation of a CH2Cl2-MeOH extract of the twigs of Coussarea paniculata using a yeast-based assay for potential DNA-damaging agents resulted in the isolation of three new lupane triterpenoids, 1-3, in addition to eight known triterpenoids, lupeol (4), lupeyl acetate (5), betulin (6), betulinic acid (7), 3-epi-betulinic acid (8), 3-epi-betulinaldehyde (9), oleanolic acid (10), and ursolic acid (11). The structures of the new compounds were established as lup-20(29)-en-3beta,25-diol (1), lup-20(29)-en-11alpha-ol-25,3beta-lactone (2), and 3-deoxybetulonic acid (3), on the basis of extensive 1D and 2D NMR spectroscopic data interpretation and chemical conversion.