Relationship of Bugula neritina (Bryozoa) antineoplastic constituents to the yellow sponge

Abstract- Lissodendoryx isodictyalis, a yellow marine animal of the Demospongiae class, was found to yield a series of closely related substances very active against the murine P388 lymphocytic leukemia. Separation studies guided by bioassay led to the isolation and character— ization of the strongly antineoplastic (P388 leukemia) bryostatins 4-6 (la-c) and 8 (141) accompanied by new bryostatins A and B. Yields of the bryostatins from 108 kg of wet Gulf of California L. isodictyalis ranged from 3.2 mg of bryostatin 4 to 900 g and 700 ig respectively of bryostatins A and B. The actual source of bryostatins 4-6 and 8 appeared to be from intrusion of the Bryozoan Bugula neritina. But bryostatins A (a deoxybryostatin 5) and B (a deoxybryostatin 4) have not hitherto been detected in. neritina and may represent metabolic transformations performed by the sponge. Marine Porifera have proved to be an exceptionally productive source of new substances with physiological activity (ref. 3). And starting, nearly 20 years ago, with initiation (ref. 4