Abstract
The results of studies of the free-radical mechanisms of the action of various antitumour antibiotics are surveyed. The data obtained in the investigation by physicochemical methods (EPR, polarographic, and spectrophotometric) as well as quantum-chemical calculations of the biotransformation processes of antitumour antibiotics, namely the formation of chemically and biologically active free-radical forms of antibiotics, are presented. The ways in which they can be transformed, including the transfer of the electron to oxygen molecules with formation of superoxide radicals, as well as covalent binding to biomacromolecules are discussed. The important role of the acid–base properties of the antibiotics in their free-radical reactions and the characteristics of the biological action of the spin-labelled analogues of anthracycline antibiotics are examined.
The bibliography includes 76 references.