Zn(II) and Pd(II) complexes derived from novel benzohydrazide-based Schiff base ligand as multi-target agents

Abstract

The synthesis of compounds that interfere with several targets is important in the biological and pharmaceutical topics. Considering the ability of Schiff bases (SB) in various biological fields, new Schiff base ligand 4-hydroxy(3-(hydroxyimino) butan-2-ylidene)benzohydrazide (L), and its Pd(II), C1, and Zn(II), C2, complexes were synthesized, and characterized. HOMO and LUMO energies, configuration optimization, and density functional theory (DFT) were calculated for the complexes. In silico predictions showed that C2 has a higher chance of being a candidate drug. So, some biological activities, and interaction of C1 and C2 with bovine liver catalase (BLC) were proven. The antioxidant capacity of complexes was as follows: C2 > C1 > L. They inhibited the catalytic activity of BLC via a mixed-type inhibition mechanism. Binding constant of C1 was slightly higher than that of C2 and with the order of 104 M−1. Van der Waals interactions and hydrogen binding play a prominent role in the binding of complexes to BLC. Both systems see a change in the enzyme's second structure as a result of the complexes' binding to BLC. Both complexes (especially C1) have catalytic capacity in reducing p-nitrophenol to p-aminophenol.