ADCs Toxins, Quinaldopeptin is a quinomycin antibiotic isolated from an Amycolatopsis sp. with strong antimicrobial and cytotoxic activity. The symmetric cyclic peptide structure of Quinaldopeptin contains two intercalating naphtyl moieties which produce a bis-intercalation of DNA base pairs, creating DNA crosslinks and disturbing natural DNA processes. Quinaldopeptin is demonstrated to have high efficacy against gram-positive bacteria and cultured B16 melanoma cells. Quinaldopeptin is related to sandramycin and luzopeptins.