Probing ferrocene-based thiosemicarbazones and their transition metal complexes as cholinesterase inhibitors

The transition metal complexes (Cu(II) and Co(II)) of ferrocene-based thiosemicarbazones hitherto were synthesized (compounds 13-39) by the condensation of different thiosemicarbazides with acetylferrocene in presence of catalytic amount of acetic acid, characterized and their inhibitory potential against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) was evaluated. Both the ligands and their metal complexes in general showed moderate to potent inhibition activity against the said enzymes. All the Cu(II) complexes were found more potent than their respective ligands or with complexes of other metals. Similarly, the studied Co(II) complexes also showed potent inhibition of enzymes inhibition and was found even higher than the standard Eserine but with slightly higher IC50 values than that of Cu(II) complexes. In silico studies supported the structure activity relationship of the compounds.