New polychlorinated pyrrolidinones from the Red Sea marine sponge Lamellodysidea herbacea

Chemical investigation of the dichloromethane extract of the Red Sea marine sponge Lamellodysidea herbacea led to the isolation of seven new polychlorinated derivatives and in addition to the known dysidamide , dysidamide B and dysidamide C . Their structures were established by extensive NMR spectroscopic data. The absolute configuration of compound was determined by X-ray crystallographic diffraction analysis. Dysidamide exhibited neurotoxic effects towards both mesencephalic and cortical murine neurones at 0.8 μg/ml.