Novel N-Heterocyclic Carbene Silver (I) Complexes: Synthesis, Structural Characterization, Antimicrobial, Antioxidant and Cytotoxicity Potential Studies

Abstract

Nowadays, N-heterocyclic carbene-based silver-complexes Ag(I) have been widely used as an organometallic drug candidate in medicinal and pharmaceutical chemistry researches due to their low toxicity. Due to the success of Ag(I) complexes in biological applications, interest in the synthesis and applications of such compounds is increasing rapidly. Therefore, in this study, a series of unsymmetrical N,N-disubstituted benzimidazolium salts were synthesized as N-heterocyclic carbene (NHC) (2a-2j). The interaction of these benzimidazolium salts having their two nitrogen atoms substituted by bulky groups with Ag2O in DMF has been carried out to afford Ag(I) complexes and characterized by 1H NMR, 13C NMR, FT-IR and elemental analyses. The antimicrobial activity of Ag(I) complexes was tested against some standard culture collections of Gram-negative, Gram-positive bacterial strains and Fungal strains, which are the most frequently isolated among the society and hospital-acquired infectious microorganisms as potential metallopharmaceutical agents. The Ag-NHC complexes showed effective antimicrobial activity against microorganisms with MIC values between 0.0024 and 1.25 mg/ml. Moreover, these Ag-NHC complexes exhibited significant antioxidant activities. In addition, of benzimidazoles salts 2,4 and Ag(I) complexes 3,5 were screened for their antitumor activity. The highest antitumor activity was observed for 3e and 3d Complexes.

Cyanopropyl functionalized benzimidazolium salts and their silver N‐heterocyclic carbene complexes: Synthesis, antimicrobial activity, and theoretical analysis

“…[ 5,6 ] In recent years, metal‐N‐heterocyclic carbene (NHC) complexes have shown promise in biomedical applications, including as antimicrobial, anticancer, and antitumor (palladium‐, copper‐, silver‐, gold‐, ruthenium‐, rhodium‐, and platinum‐NHC) agents. [ 7–36 ] The efficacy of a silver‐based drug appears to be linked to its bioavailability [ 13,37 ] which is affected by, for example, its solubility and the presence of biological ligands and halides. The release rate of silver from a prodrug is linked to the ancillary ligand, and as NHCs are strong σ donors, silver‐NHCs can have a slow silver release rate.…”

Silver complexes with substituted terpyridines as promising anticancer metallodrugs and their crystal structure, photoluminescence, and DNA interactions

“…[45][46][47] Among these metal ions, silver is used to synthesize new complexes which exhibit excellent antibacterial and antitumor activity. [48][49][50] Several recent studies focusing on selective cytotoxicity have suggested that their silver complexes provoked intracellular reactive oxygen species (ROS) overproduction and mitochondrial membrane depolarization, which eventually resulted in mitochondrial dysfunction and cell potent necrosis. [51][52][53] However, in vitro experiments that enable a precise determination of how a compound interacts with DNA are rare and the structure-activity relationship remains unexplored.…”

A Fluoroponytailed NHC–Silver Complex Formed from Vinylimidazolium/AgNO3 under Aqueous–Ammoniacal Conditions

“…Molecules 2022, 27, 4137 2 of 9 NHC derivatives) exhibit good biocompatibility and have opened new horizons in life sciences [16][17][18]. In particular, they garnered enormous attention in biological as well as pharmaceutical research, for example, as antimicrobial [19][20][21][22] and cytostatic agents [23][24][25][26][27]. The profiles of bioactivity depend on either lipophilicity [28] or fluorophilicity [29], which in turn are primarily contingent on the chain length of the nitrogen substituents.…”