Synthesis and Enzyme Inhibitory Properties of Quinoxaline Bridged Bis(imidazolium) Salts

In this study, a series of new salts containing quinoxaline and imidazole moieties were synthesized in good yield by the reaction of 2,3 -bis(bromomethyl)quinoxalines and 1-alkylimidazoles in N,N-dimethylformamide. These salts were characterized by elemental analysis, IR, H-1 NMR and C-13 NMR spectroscopy, which support the proposed structures. Furthermore, the enzyme inhibition activities of these compounds were investigated. They showed highly potent inhibition effect on acetylcholinesterase (AChE) and carbonic anhydrases (hCAs) (Ki values are in the range of 44.80 +/- 14.87 to 288.64 +/- 42.68 nM, 21.50 +/- 4.76 to 187.30 +/- 22.43 nM, and 5.81 +/- 0.71 to 164.52 +/- 26.0 nM for AChE, hCA I, and hCA II, respectively). Compound 3 showed the best inhibition effect for hCA I and compound 4 showed the best inhibition effect for hCA II and AChE.