Unveiling the molecular association of novel benzohydrazide-substituted Schiff base complexes with human serum albumin

So far, various Schiff base zinc (II) complexes with potential applications in biomedicine have been reported as medicinal agents in diagnosis, imaging and treatment of diseases such as cancer and Alzheimer. Therefore, it is important to understand their interaction with carrier proteins, such as human serum albumin (HSA). The present paper focuses on synthesis, characterization and the binding interactions between HSA and two novel Schiff-base complexes, [Zn(SL)(N-N)](NO3)(2) (SL = Schiff base ligand; N-N = 2,2 '-bipyridine (bpy, C1), 1,10-phenanthroline (phen, C2)), using experimental and molecular docking techniques. The antioxidant performance of compounds increased as follows: C2 > C1 > SL. Two complexes quenched the protein fluorescence emission by the same mechanism (static quenching). The binding constant values obtained from the interaction of HSA and complexes were in the ideal range for biological applications (K-b = 0.07 x 10(4) M-1 for C1, 5.01 x 10(4) M-1 for C2 at 303 K). The binding of the C1/C2 somewhat reduced the stability of the protein structure and led to a change in polarity around tyrosine and tryptophan. In this research, we found that the increase of the planar aromatic part in the metallodrug can affect the strength of the interaction, the type of force involved during the interaction process, and the medicinal properties such as their antioxidant capabilities.