Quantum chemical analysis of the deferiprone–iron binding reaction

To prevent side effects of excessive accumulation of iron in the body, chelation therapy is recommended in transfusion-dependent patients. The reaction between deferiprone and iron to form a complex red substance can be described as 3 molecules of the chelator, deferiprone, reacting with a molecule of iron. However, the actual mechanism of the deferiprone-iron binding reaction is not well understood. A quantum chemical analysis of the deferiprone-iron binding reaction was performed, focusing on the reaction between 1 molecule of deferiprone and I molecule of iron. The two main alternative pathways for the deferiprone-iron binding reaction were shown to be C-C cleavage and C-O cleavage. The required energy for complex formation in C-C cleavage was less than for C-O cleavage. The total energy requirement for C-C cleavage was negative, implying that this reaction can occur without any external energy source. The resulting complex fits the reported tertiary structure model for the deferiprone-iron complex.