Prenylated Flavonoid Derivatives from the Bark of Erythrina addisoniae

Two new prenylated flavanones, 2S-3′-(2-hydroxy-3-methylbut-3-enyl)licoflavone-4′-methyl ether (3) and 2S-3′-(2-hydroxy-3-methylbut-3-enyl)abyssinone II (4), and four known flavanones (1, 2, 5, 6) were isolated from the stem bark of Erythrina addisoniae. The structures were elucidated on the basis of their spectroscopic and physicochemical data. None of the compounds showed antioxidative properties. 4′-Methylabyssinone V (1) and abyssinoflavanone VII (6) showed moderate cytotoxic activity (IC50 = 5 and 3.5 µmol/L, respectively), but apoptosis (caspase-3/7-activation, nuclear fragmentation) was selectively induced by abyssinoflavanone VII (6).