Swinhoeiamide A, a new highly active calyculin derivative from the marine sponge Theonella swinhoei

Analysis of the Papua New Guinean sponge Theonella swinhoei afforded a new calyculinamide related congener for which we propose the name swinhoeiamide A (1) The structure of the new compound was unambiguously established on the basis of NMR spectroscopic (H-1, C-13 COSY, HMBC) and mass spectrometric (FABMS) data Swinhoeiamide A exhibited insecticidal activity toward neonate larvae of the polyphagous pest insect Spodoptera littoralis when incorporated in an artificial diet offered to the larvae in a chronic feeding bioassay (ED50 2 11 ppm, LD50 2 98 ppm) Furthermore, it was found to be fungicidal against Candida albicans and Aspergillus fumigatus (MIC 12 and 1 mug/mL, respectively).