Bisbenzylisoquinoline and hasubanane alkaloids from Stephania abyssinica (Dillon & A. Rich) (Menispermeceae)

From the leaves of Stephania abyssinica, three alkaloids were isolated: (−)-pseudocurine (1), (−)-pseudoisocurine (2) and (−)-10-oxoaknadinine (3). (−)-Pseudocurine and (-)-pseudoisocurine showed strong anti-plasmodial activity against both chloroquine-susceptible D6 and resistant strains of Plasmodium falciparum (IC50 0.29 ± 0.00 and 0.31 ± 0.01 μg/ml, respectively) while (−)-pseudoisocurine exhibited moderate and mild activity (0.75 ± 0.11 and 1.65 ± 0.03 μg/ml).98