Cosmomycin D, a New Anthracycline Antibiotic

In the course of studies on antitumor anthracycline antibiotics, the authors have isolated cosmomycin D, a new member of the beta -rhodomycin group, from the mycelium extract of Streptomyces cosmosus TMF518. From this strain three other anthracycline compounds were purified. They are cosmomycins A and B, belonging to the gamma -rhodomycin group of antibiotics, and cosmomycin C, identified as beta -rhodomycin S-2. The authors report here on the elucidation of the structures of cosmomycins C and D.