Swinhoeiamide A, a New Highly Active Calyculin Derivative from the Marine Sponge <i>Theonella </i><i>s</i><i>winhoei</i>

Abstract

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 ((1)H, (13)C, 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 (ED(50) 2.11 ppm, LD(50) 2.98 ppm). Furthermore, it was found to be fungicidal against Candida albicans and Aspergillus fumigatus (MIC 1.2 and 1.0 microg/mL, respectively).