Synthesis, characterization and bioactivities of dative donor ligand N-heterocyclic carbene (NHC) precursors and their Ag(I)NHC coordination compounds

Abstract

This study contains the synthesis of N-phthalimidomethyl-substituted NHC precursors and their Ag(I)NHC coordination compounds. The NHC precursors were synthesized from the 1-(N-phthalimidomethyl)benzimidazole and alkyl/aryl halide. The Ag(I)NHC coordination compounds were synthesized from the N-phthalimidomethyl substituted benzimidazolium salts and silver oxide via the in-situ deprotonation method. The formation of all compounds was proved fully by 1H NMR, 13C NMR, FTIR and elemental analysis techniques. Also, these novel N-phthalimidomethyl substituted NHC precursors and Ag(I)NHC coordination compounds were found as effective inhibitors for acetylcholinesterase (AChE), human carbonic anhydrase I isoenzyme (hCA I), human carbonic anhydrase II isoenzyme (hCA II), and butyrylcholinesterase (BChE) with inhibition constants (Kis) in the range of 1.00 ± 0.14–2.31 ± 0.58 µM for hCA I, 1.30 ± 0.21–2.85 ± 0.56 µM for hCA II, 0.35 ± 0.06–2.58 ± 0.70 µM for AChE, and 0.42 ± 0.01–1.27 ± 0.16 µM for BChE, respectively.