Mitomycin B

**Semantic type:** Amino Acid, Peptide, or Protein|Antibiotic|Pharmacologic Substance

**Definition:** A methylazirinopyrroloindoledione antineoplastic antibiotic isolated from the bacterium Streptomyces caespitosus. Bioreduced mitomycin B generates oxygen radicals, alkylates DNA, and produces interstrand DNA cross-links, thereby inhibiting DNA synthesis. (NCI04)

**Synonyms:** - Azirino(2',3':3,4)pyrrolo(1,2-a)indole-4,7-dione, 1,1a,2,8,8a,8b-hexahydro-8a-hydroxy-8-(hydroxymethyl)-6-methoxy-1,5-dimethyl-, 8-carbamate - MITOMYCIN B