NEW VARIANTS OF DINITROSYL IRON COMPLEXES. ANTIOXIDANT AND ANTIRADICAL EFFECT
Dinitrosyl iron complexes (DNICs) are important metabolites of nitric oxide (NO) with a wide range of biological activity. The properties of these complexes are determined not only by NO-ligands, but also by other components included in their composition. Using EPR spectroscopy, it was shown that iron in the DNICs can be bound to carnosine, L-ergothioneine and ADP. New variants of DNICs are formed with the participation of a nitroxyl anion, which is a product of one-electron reduction of NO. In model systems, DNICs associated with carnosine and ergothioneine reduce the level of various free radicals. These DNICs intercept the superoxide anion radical, which is a precursor to other reactive oxygen and nitrogen species. At the same time, carnosine-bound DNICs reduce the concentration of organic free radicals in a system containing a nitroxyl anion, iron ions and tert-butyl hydroperoxide. On the other hand, DNICs associated with ergothioneine and ADP may play an important role in the protection of mitochondria. It has been suggested that the new DNICs may be components of antioxidant systems localized in various tissues of the body, as well as redox triggers regulating the cellular response to oxidative stress.