In this article, hemin structure was modified by conjugation to tyrosine or tyramine via carbodiimide reaction or to styrene via cross-metathesis reaction, with full characterization of the resulting conjugates (fig. ). Next, the nature of complexation of each compound with • NO was studied at the level of density functional theory (DFT) using quantum mechanics. The affinity of each compound towards • NO was then studied electrochemically and via fluorescence measurements. In addition, the affinity of binding between the tested compounds and BSA was evaluated alongside the study of the cellular uptake of each through the quantification of the cellular iron content. Then, the intracellular levels of • NO were measured after the treatment of normal and iNOS-transfected cells with the different compounds in the presence/absence of extracellular • NO. Finally, the downstream effects of