Nogalamycin is an unusual anthracycline antineoplastic antibiotic isolated from the bacterium Streptomyces nogalater. Nogalamycin intercalates into DNA and interacts with topoisomerase I, thereby inhibiting DNA replication and repair and RNA and protein synthesis. Nogalamycin contains two saccharides. The neutral monosaccharide attaches to the D ring, similar to the aminoglycoside moieties of the doxorubicin class, while the second, basic saccharide attaches to the phenolic group on the A ring in the ortho position to form a unique family of hexacyclic anthracyclines. Nogalamycin is potent antibacterial and antitumor agent. Nogalamycin was markedly cytotoxic in vitro and was active against several tumor systems in vivo.