A New Epidioxy Sterol as an Antifouling Substance from a Palauan Marine Sponge, Lendenfeldia chondrodes

Bioassay-guided fractionation of an extract of a marine sponge, Lendenfeldia chondrodes, has led to the isolation and identification of new epidioxy sterols 1a and 1b as an inseparable mixture. Two known epidioxy sterols 2 and 3 and three known sesterterpenes 4-6 were also isolated from the same extract. These compounds showed repellent activity against the blue mussel Mytilus edulis galloprovincialis.