New spirocyclic sesquiterpenes from the marine sponge Geodia exigua

Article abstract of DOI:10.1016/S0040-4020(02)01619-8

Three new spirocyclic sesquiterpenes designated exiguamide (1), exicarbamate (2) and exigurin (3), together with (-)-10-epi-axisonitrile-3 (4), have been isolated from the marine sponge Geodia exigua. All four compounds possess the spiro[4.5]decene skeleton and their structures were determined on the basis of spectroscopic data. The structure of 1 was confirmed by X-ray crystallographic analysis and the absolute configuration was determined by applying the modified Mosher's method on its amine derivative. Exiguamide (1) inhibited cell fate specification during sea urchin embryogenesis at a minimum inhibitory concentration of 0.4μM.