NEW CYTOTOXIC PEROXYLACTONES FROM THE MARINE SPONGE, PLAKINASTRELLA ONKODES

Three new peroxylactones, plakorrolides B [6], C [7], and D [8], and a new peroxy ester, epiplakinic acid E methyl ester [9], were isolated and characterized from a previously unstudied marine sponge, Plakinast rella onkodes. A mixture of steroidal peroxides was also found in this organism. Plakorrolides B [6] and D [8], and epiplakinic acid E methy l ester [9], were evaluated for biological activity and found to show cytotoxicity against the A549 human lung carcinoma and P388 murine leu kemia cell lines, and to effect adhesion in an assay employing the EL4 .IL-2 cell Line, which correlates with signal transduction activity.