A new bispyrroloiminoquinone alkaloid, tsitsikammamine C (1), displayed potent in vitro antimalarial activity with IC 50 values of 13 and 18 nM against chloroquine-sensitive (3D7) and chloroquine-resistant (Dd2) Plasmodium falciparum, respectively. Tsitsikammamine C (1) displayed selectivity indices of >200 against HEK293 cells and inhibited both ring and trophozoite stages of the malaria parasite life cycle. Previously reported compounds makaluvamines J (2), G (3), L (4), K (5) and damirones A (6) and B (7) were also isolated from the same marine sponge (Zyzzya sp.). Compounds 2-4 displayed potent growth inhibitory activity (IC 50 <100 nM) against both P. falciparum lines and only moderate cytotoxicity against HEK293 cells (IC 50 = 1-4 ?M). Makaluvamine G (3) was not toxic to mice and suppressed parasite growth in P. berghei infected mice following subcutaneous administration at 8 mg kg -1 day -1.
Davis, R. A., Buchanan, M. S., Duffy, S., Avery, V. M., Charman, S. A., Charman, W. N.
, ... Quinn, R. J. (2012). Antimalarial activity of pyrroloiminoquinones from the Australian marine sponge Zyzzya sp. Journal of Medicinal Chemistry
(12), 5851 - 5858. https://doi.org/10.1021/jm3002795