DNA-and BSA-binding properties of dichloro(1-methallyl-3-arylmethyl-5,6-dimethylbenzimidazolin-2-ylidene)pyridine palladium(II) complexes

Aims A synthesis of five palladium(II) complexes was conducted, and their binding affinities against deoxyribonucleic acid (DNA) and Bovine Serum Albumin (BSA) were evaluated.Materials & methods The PEPPSI-type complexes, dichloro[1-methallyl-3-(4-methylbenzyl)-5,6-dimethylbenzimidazolin-2-ylidene]pyridine palladium(II) (2a), dichloro[1-methallyl-3-(4-chlorobenzyl)-5,6-dimethylbenzimidazolin-2-ylidene]pyridine palladium(II) (2b), dichloro[1-methallyl-3-(4-tert-butylbenzyl)-5,6-dimethylbenzimidazolin-2-ylidene]pyridine palladium(II) (2c), dichloro[1-methallyl-3-(4-methoxybenzyl)-5,6-dimethylbenzimidazolin-2-ylidene]pyridine palladium(II) (2d) and dichloro[1-methallyl-3-(2,3,5,6-tetramethylbenzyl)-5,6-dimethylbenzimidazolin-2-ylidene]pyridine palladium(II) (2e), were synthetized in 74–82% yields. The structural characterization of the complexes was conducted through the utilization of 1H and 13C Nuclear magnetic resonance (NMR) spectroscopy, in conjunction with Fourier transform infrared (FT-IR) spectroscopy, mass spectroscopy and elemental analysis. DNA- and BSA-binding evaluation was performed spectroscopically with Benesi–Hildebrand Method and theoretically with molecular docking method.Results and conclusions According to the experimental method, complex 2a exhibited the strongest binding constant against DNA (1.84 × 104 M−1), while complex 2c demonstrated the highest BSA binding constant (2.83 × 104 M−1). Subsequent to molecular docking, and consistent with experimental findings, it was determined that all molecules exhibited interaction with the same DNA and BSA residues. Complex 2a demonstrated the strongest binding affinity against DNA, while complex 2c manifested the most robust interaction with a binding value of −8.09 kcal/mol. A thorough evaluation of the drug-likeness properties of the palladium(II) complexes was conducted using the SwissADME web tool.