Iron(III)-binding of the anticancer agents doxorubicin and vosaroxin

{The Fe(III)-binding constant of vosaroxin, an anticancer quinolone derivative, has been determined spectrophotometrically and compared with the analogous Fe(III) complex formed with doxorubicin. The in vivo metabolic stability and iron coordination properties of the quinolones compared to the anthracylines may provide significant benefit to cardiovascular safety. The mechanism of action of both molecules target the topoisomerase II enzyme. Both doxorubicin (Hdox, log beta(FeL3) = 33.41