Résumé : Adriamycin cardiotoxicity has been correlated with a disturbance of heart mitochondrial functions. Here, 5-iminodaunorubicin was compared with adriamycin for its capability to interfere in the mitochondrial electron transport with subsequent membrane damaging. The results suggest that minor chemical modifications of the anthraquinone moiety of anthracycline glycoside drugs should be a promising way to decrease mitochondrial membrane damage induced by this class of antitumor drugs.