4'-N-methyl-5'-hydroxystaurosporine and 5'-hydroxystaurosporine, new indolocarbazole alkaloids from a marine Micromonospora sp. strain.

Two new indolocarbazole alkaloids, 4'-N-methyl-5'-hydroxystaurosporine (2) and 5'-hydroxystaurosporine (3), were isolated together with the known staurosporine (1) from the culture broth of a marine Micromonospora sp. (strain L-31-CLCO-002). The fermentation, structural data and cytotoxic activities of these compounds against various tumor cell lines are given.