A semisynthetic analog of Bleomycin, a mixture of several basic glycopeptide antineoplastic antibiotics isolated from the fungus Streptomyces verticillus. Peplomycin forms complexes with iron that reduce molecular oxygen to superoxide and hydroxyl radicals that cause single- and double-stranded breaks in DNA. This agent appears to show greater antitumor activity than bleomycin; its use is limited due to pulmonary toxicity.