ANTINEOPLASTIC AGENTS - 386 - ISOLATION OF SESTERSTATINS-1-3 FROM THEMARINE SPONGE HYRTIOS-ERECTA

The Republic of Maldives' black marine sponge Hyrtios erecta has been found to contain three cancer cell-line inhibitory pentacyclic sestert erpenes designated sesterstatins 1-3 (2-4). One of the sesterterpenes, sesterstatin 2, specifically inhibited the Gram-positive opportunist Staphylococcus aureus. All three of the P-388 lymphocytic-leukemia-act ive (ED50 0.46 to 4.3 mu g/mL) sesterstatins were obtained in trace qu antities (3.0 x 10(-7) to 5.4 x 10(-7)% yields) and represent structur al variations on the more usual scalarin-type porifera sesterterpenes. The structures were elucidated by highfield (500 MHz) 2D NMR techniqu es augmented by HRMS results.