BMY-28438 (3,7-dihydroxytropolone), a new antitumor antibiotic active against B16 melanoma. I. Production, isolation, structure and biological activity.

A new antitumor antibiotic BMY-28438 was isolated from the cultured broth of Streptomyces tropolofaciens No. K611-97. The antibiotic showed potent cytotoxicity against cultured B16 melanoma cells and remarkable prolongation of life span of mice bearing B16 melanoma. The structure of BMY-28438 was determined as 3,7-dihydroxytropolone on the basis of spectral analyses and direct comparison with the authentic compound synthesized.