New silver N-heterocyclic carbene (NHC) complexes containing fluoro and acetyl groups: design, characterization, molecular docking studies, and inhibition properties against several metabolic enzymes

This study presents the synthesis of acetyl- and fluorinated group-containing imidazol-2-ylidene silver complexes. The structures of the complexes obtained via deprotonation method were elucidated using spectroscopic techniques such as NMR, FTIR, and MS, as well as elemental analysis. In addition, the enzyme inhibition profiles of the synthesized Ag(I)-NHC complexes were thoroughly investigated against human carbonic anhydrase isoforms I and II (hCAs I and II), as well as acetylcholinesterase (AChE). Notably, compound 2f, bearing 2-chloro and 4-fluoro groups, exhibited superior inhibition potency against hCA I and AChE enzymes, with Ki values outperforming the reference inhibitors acetazolamide (AZA) and tacrine (TAC). These findings suggest that the dual halogenation pattern enhances both electrostatic and hydrophobic interactions within enzyme active sites. In addition, the cytotoxic activity of compound 2f was determined using MTT assays in SH-SY5Y (neuroblastoma), HCT-116 (colorectal carcinoma), and MCF-7 (breast adenocarcinoma) cell lines, yielding IC₅₀ values of 35.63 ± 0.84 μM, 49.37 ± 0.97 μM, and 54.92 ± 1.94 μM, respectively. Further, we examined the inhibition potential of three most potent compounds (2a, 2e and 2f) with in silico molecular docking with three target proteins (hCA I, hCA II, and AChE). The binding energy score and ligand-protein interactions were indicating excellent inhibition potential of examined compounds. Overall, these results highlight the multi-target enzyme-blocking ability of 2f as a promising candidate for suppressing tumor growth.