Synthesis, crystal structure and biological evaluation of spectroscopic characterization of Ni(II) and Co(II) complexes with N-salicyloil-N'-maleoil-hydrazine as anticholinergic and antidiabetic agents.

[Ni(C H N O ) (H O) ]•3(C H NO) (1) and [Co(C H N O ) (H O) ]•3(C H NO) (2) are synthesized and characterized by elemental analysis, FT-IR spectra, magnetic susceptibility, and thermal analysis. In addition, the crystal structure of Ni(II) complex is presented. Both complexes show distorted octahedral geometry. In 1 and 2, metal ions are coordinated by two oxygen atoms of salicylic residue and two nitrogen atoms of maleic amide residue from two ligands, and two oxygen atoms from two water molecules. In this paper, both compounds showed excellent inhibitory effects against human carbonic anhydrase (hCA) isoforms I, and II, α-glycosidase, acetylcholinesterase (AChE), and butyrylcholinesterase (BChE). Compounds 1 and 2 had Ki values of 18.36 ± 4.38 and 26.61 ± 7.54 nM against hCA I and 13.81 ± 3.02 and 29.56 ± 6.52 nM against hCA II, respectively. On the other hand, their Ki values were found to be 487.45 ± 54.18 and 453.81 ± 118.61 nM against AChE and 199.21 ± 50.35 and 409.41 ± 6.86 nM against BChE, respectively.