Bioactivity of amphitoxin, the major constituent of the Jamaican sponge Amphimedon compressa.

Fractionation of the MeOH/CH2Cl2 extract of the sponge Amphimedon compressa afforded the secondary metabolite amphitoxin (1), the structure of which was elucidated by interpretation of 1H- and 13C-NMR data. The crude extract and the fractions containing the metabolite 1 were assessed for ichthyotoxic and insecticidal activity towards Xiphophorus variatus (moon fish) and Cylas formicarius elegantulus (sweet potato weevil), respectively. In addition, the ability of 1 to cause mortality (toxicity and lethal effect) in the rodent Rattus norvegicus (Norway rat) was examined.