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 H-1 NMR, C-13 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 (K(i)s) in the range of 1.00 +/- 0.14-2.31 +/- 0.58 mu M for hCA I, 1.30 +/- 0.21-2.85 +/- 0.56 mu M for hCA II, 0.35 +/- 0.06-2.58 +/- 0.70 mu M for AChE, and 0.42 +/- 0.01- 1.27 +/- 0.16 mu M for BChE, respectively. (C) 2020 Elsevier Ltd. All rights reserved.