To Transfer or Not to Transfer? Development of a Dinitrosyl Iron Complex as a Nitroxyl Donor for the Nitroxylation of an FeIII-Porphyrin Center

A positive myocardial inotropic effect achieved using HNO/NO-, compared with NO· triggered attempts to explore novel nitroxyl donors for use in clinical applications in vascular and myocardial pharmacology. To develop M-NO complexes for nitroxyl chemistry and biology, modulation of direct nitroxyl-transfer reactivity of dinitrosyl iron complexes (DNICs) is investigated in this study using a FeIII-porphyrin complex and proteins as a specific probe. Stable dinuclear {Fe(NO)2}9 DNIC [Fe(μ-MePyr)(NO)2]2 was discovered as a potent nitroxyl donor for nitroxylation of FeIII-heme centers through an associative mechanism. Beyond the efficient nitroxyl transfer, transformation of DNICs into a chemical biology probe for nitroxyl and for pharmaceutical applications demands further efforts using in vitro/in vivo studies. A dinitrosyl iron complex, DNIC [Fe(μ-MePyr)(NO)2]2, was found to be a potent nitroxyl donor for prospective clinical applications in vascular and myocardial pharmacology.