AN IMPROVED SOURCE OF BRYOSTATIN-10, BUGULA-NERITINA FROM THE GULF-OF-AOMORI, JAPAN

Bryostatins have been isolated from diverse Japanese coastal specimens of Bugula neritina guided by inhibitory activity against fertilized s ea urchin egg cell division. B. neritina from the Gulf of Aomori, Japa n, has been found to contain bryostatin 10 [1b] in high yield (10(-3)% ) for this class of compounds. The H-1- and C-13-nmr signals of bryost atin 10 [1b] were reassigned by 2D nmr techniques. The conformation of bryostatin 10 [1b] in solution was revealed by nmr studies. This comp ound also exhibited activity in a steroidogenesis assay by increasing the production of adrenocortical hormones nearly twofold.