CAS 1403-29-8. A natural antibiotic produced by a Streptomyces strain. Discovered in Japan in the 1950s, it has strong antitumor potential, though its toxicity may preclude medical use. It is a member of the so-called bis-intercalator group of antibiotics that act by interlocking between the nucleotide bases of DNA; thus it may have mutagenic activity. The molecule contains carbon, oxygen, hydrogen, and nitrogen. The structure was elucidated in 1982.