Antitrypanosomal pyridoacridine alkaloids from the Australian ascidian Polysyncraton echinatum

Bioassay-guided fractionation of the crude CH(2)Cl(2)/MeOH extract from the Australian ascidian Polysyncraton echinatum led to the isolation of a new pyridoacridine alkaloid, 12-deoxyascididemin (1), along with two known analogues, ascididemin (2) and eilatin (3). The structure of 1 was determined following extensive analysis of 1D/2D NMR and MS data. Biological evaluation showed that compounds 1-3 are potent antitrypanosomal agents with IC(50) values of 0.077, 0.032, and 1.33 mu M against Tryponosoma brucei brucei, respectively. (C) 2010 Elsevier Ltd. All rights reserved.