Vanadyl (III)-(E)-N′-(3,5-di-tert-butyl-2-hydroxybenzylidene)-nicotinohydrazide complex: Synthesis, characterization and in vitro and in silico cholinesterase and α-glucosidase inhibition studies

Abstract

A new ligand N-nicotinoyl-N '-(3,5-ditertbuthyl-2-hydroxy)benzylidene hidrazine (H2L) was synthesized and a complex [VO(L)CH3O & sdot;CH3OH] with this ligand was obtained and their structures investigated by X-ray crystallography. It was found that the methanol molecule in the complex is easily exchanged for a pyridine molecule. The effects of H2L and [VO(L)CH3O CH3OH] complexes against AChE, BChE and alpha-glucosidase enzymes were investigated using Ellman and Tao methods and the results were calculated as IC50 and Ki. Both compounds demonstrated effective inhibition of all three enzymes, with varying degrees of potency. For AChE, H2L exhibited the lowest IC50 value (8.45 mu M, r2 = 0.993) and a Ki of 5.53 +/- 0.73 mu M, outperforming both its vanadium complex (IC50 = 10.61 mu M, Ki = 7.38 +/- 1.14 mu M) and the reference drug tacrine (IC50 = 13.75 mu M, Ki = 11.90 +/- 1.01 mu M). Additionally, Molecular docking studies were performed to elucidate the possible inhibition mechanisms and binding modes of the ligand (H2L) and its vanadium complex [VO(L)(CH3O)& sdot;CH3OH] against three target enzymes: acetylcholinesterase (AChE, PDB ID: 4EY7), butyrylcholinesterase (BChE, PDB ID: 6EQP), and alpha-glucosidase (alpha-Glu, PDB ID: 3WY1). To achieve a more accurate prediction of ligand-protein interactions and account for conformational flexibility, Induced Fit Docking (IFD) protocols were employed. These two complexes were studied in vitro and in silico and it was determined that they may be used for drug design.