Isolation of Spirastrellolides A and B from a Marine Sponge <i>Epipolasis</i> sp. and Their Cytotoxic Activities

Abstract

Spirastrellolides A (<b>1</b>) and B (<b>3</b>) have been isolated as free acids from a marine sponge <i>Epipolasis</i> sp. collected in the East China Sea. These compounds had been isolated from the Caribbean marine sponge <i>Spirastrella coccinea</i> after conversion to the methyl ester. We examined the cytotoxic activities of <b>1</b> and <b>3</b> and found that the activities of the free acids are comparable to those of the corresponding methyl esters