echinomycin

Echinomycin is a cytotoxic polypeptide quinoxaline antibiotic originally isolated from Streptomyces echinatus. It is a cyclic peptide and dimer, containing a bicyclic aromatic chromophore attached to the peptide core via a thioacetal bridge. Echinomycin acts as a bifunctional DNA bis-intercalator, binding specifically to double-stranded DNA at CpG sites (notably 5'-CG-3' sequences), thereby inhibiting RNA synthesis and blocking the binding of hypoxia-inducible factor 1 alpha (HIF1A). This mechanism underlies its antimicrobial and antitumor properties. Echinomycin was brought into clinical trials by the National Cancer Institute for its antitumor activity but showed minimal efficacy in phase II studies despite potent preclinical effects[1][2][4][5][6].

Other names

quinomycin A