New macrolides from the sponge Chondrosia corticata.

Three new oxazole-containing metabolites, neohalichondramide (5), (19Z)-halichondramide (6), and secohalichondramide (7), along with four previously reported compounds of the same structural class were isolated from the marine sponge Chondrosia corticata collected from Guam. The structures of novel compounds were determined on the basis of combined spectroscopic analyses. These compounds exhibited significant cytotoxicity and antifungal activity toward the human leukemia cell-line K562 and Candida albicans, respectively.