“…16 The occurrence of a sterically bulky and hydrophobic tert-butyl group adjacent to the lactone ester in bastimolide may protect it from hydrolysis, as was found for palmyrolide A. 17 A major focus of the Panama ICBG program has been the discovery of new classes of agents for the treatment of neglected tropical diseases such as malaria, leishmaniasis, and Chagas disease. 18,19 Thus, bastimolide A (1) was evaluated against a panel of these various human parasites and, remarkably, showed highly potent and selective antimalarial activity against four resistant strains of Plasmodium falciparum [TM90-C2A (chloroquine, mefloquine, and pyrimethamine resistant), TM90-C2B (chloroquine, mefloquine, pyrimethamine, and atovaquone resistant), W2 (chloroquine and pyrimethamine resistant), and TM91-C235 (chloroquine, mefloquine, and pyrimethamine resistant)] with IC 50 values of 80, 90, 140, and 270 nM, respectively.…”