Halishigamides A−D, New Cytotoxic Oxazole-Containing Metabolites from Okinawan Sponge Halichondria sp.

Four new oxazole-containing compounds, halishigamides A−D ( 1 − 4 ), have been isolated from an Okinawan marine sponge Halichondria sp. and the structures elucidated on the basis of 2D NMR data. Halishigamide A ( 1 ) is the first trisoxazole-containing macrolide possessing a primary amino group in the macrolactone ring.