Flavanoids and Pterocarpans from the Bark of Erythrina fusca

Three new isomeric flavanones, fuscaflavanones A, (1), A(2) (2) and B (3) together with six known flavanones, lupinifolin (4), lonchocarpol A (5), a mixture of lonchocarpols C-1 and C-2 (6a, b), and a mixture of lonchocarpols D-1 and D-2 (7a, b), five pterocarpans, sandwicensin (8), phaseollidin (9), erythrabissin I (10), and a mixture of dolichins A and B (11a, b), one chalcone, isobavachalcone (12), and one isoflavone, wighteone (13), were isolated from the bark of Erythrina fusca LOUR. Their structures were elucidated on the basis of spectroscopic data. Some isolates were tested for antiplasmodial and cytotoxic activities and it was found that 5 and 9 exhibited moderate antiplasmodial activity against Plasmodium falciparum. For cytotoxicity, compounds 1, 4, 5, 9 and 12 showed moderate to weak activity against KB, BC and NCI-H187 cells, whereas 2 exhibited only weak activity against KB cells.