(+)-7-Bromotrypargine: an antimalarial β-carboline from the Australian marine sponge Ancorina sp.

Mass-directed isolation of the CH2Cl2/MeOH extract from the Australian marine sponge Ancorina sp. resulted in the purification of a new antimalarial β-carboline, (+)-7-bromotrypargine 1, along with the previously isolated natural product, 6-bromotryptamine 2. The structure of 1 is determined by extensive 1D/2D NMR and MS data analyses. Comparison of the chiro-optical data for 1 with literature values of related natural products is used to determine the absolute stereochemistry of (+)-7-bromotrypargine as 1R. Antimalarial activity data for 1 and 2 against a chloroquine-resistant (Dd2) and chloroquine-sensitive (3D7) Plasmodium falciparum strain are also provided.