Zinc isoporphyrin from [Zn(4-Cl)TPP]: Synthesis, characterization, density functional theory and molecular docking studies

This study concerns the synthesis of zinc isoporphyrin (2), from zinc porphyrin [Zn(4-Cl)TPP], (1), where TPP- tetraphenylporphyrin ligand. Because of the prospective applications such as an infrared dye and catalyst in photomedicine, isoporphyrin has been in high demand. However, there is limited documentation of metalloisoporphyrins. Here, we have discussed the synthesis, characterization, coordination chemistry and theoretical studies of zinc isoporphyrin, 2. Compound 2 was characterized using UV–visible, ¹H NMR, ¹³C NMR and ESI Mass analysis. Electrochemical studies were carried out using cyclic voltammetry. Theoretical studies including structure optimization, analysis of electronic transition, and natural bond analysis (NBO) were performed for both 1 and 2. Besides that, the global reactivity indices of 1 were compared with 2. The lower HOMO-LUMO energy gap in 2 (1.95 eV) supports the shifting of Q bands to a lower energy region. The molecular docking studies of 1 and 2 were performed for the first time and found that isoporphyrins can act as a potential inhibitor of G-quartet DNA associated with cancer disease. These results may be useful in designing effective therapeutics for the treatment of cancer.