Antineoplastic agents, 116. An evaluation of the marine ascidian Aplidium californicum

The antineoplastic constituents of the marine ascidian Aplidium californicum were found to be bryostatins 4 and 5. Bioassay-directed isolation procedures using the National Cancer Institute's P-388 lymphocytic leukemia system led to the bryostatins. The probable symbiotic relationship between A. californicum and the bryozoan Bugula neritina was discussed.