The First Row Transitional Metals Effects on Stabilization of BiliverdinComplexes, Theortical Study

Biliverdin is a product of heme catabolism. It is the pigment responsible for a greenish colorsometimes seen in bruises. Biliverdin has been found in excess in the blood of humans sufferingfrom hepatic diseases. Structure of biliverdin from catabolism process of heme is one of thecases that has been less discussed.In this research characterization of biliverdin analogues in thepresence of hydroxide as a nucleophile and imidazole as axial ligands was investigated using theB۳LYP method and the ۶-۳۱G basis set both in gas and solvent phases.Theoretical studies haveshown that the absolute energy of the metal biliverdins increase with atomic mass both in gasand solvent phases. By changing the central metal in the structure of billiverdin, some featuressuch as gap energy, hardness and softness, electrophilicicity index and exact polarizability werestudied and copmared with iron. the nickel and vanadium biliverdinhave the least stability in gasand solvent phases respectively and the titanium biliverdin has the most one in both gas andsolvent phases. Calculation of hardness (η) of these complexes confirms these stabilities inwhich the titanium is the hardest among the other metals.Electrophilicity calculation shows thenickel biliverdin in gas phase and copper in solvent phase are the most electrophile.

کلیدواژه ها:

hemeoxygenase ، b۳lyp ، first row transitional metal biliverdin ، heme degradation