Definition

A mixture of glycopeptide antineoplastic antibiotics isolated from the bacterium Streptomyces verticillus. Bleomycin forms complexes with iron that reduce molecular oxygen to superoxide and hydroxyl radicals which cause single- and double-stranded breaks in DNA; these reactive oxygen species also induce lipid peroxidation, carbohydrate oxidation, and alterations in prostaglandin synthesis and degradation.