Silver (I) N-Heterocyclic Carbene Complexes: A Winning and Broad Spectrum of Antimicrobial Properties
Open Access
- 2 March 2021
- journal article
- research article
- Published by MDPI AG in International Journal of Molecular Sciences
- Vol. 22 (5), 2497
- https://doi.org/10.3390/ijms22052497
Abstract
The evolution of antibacterial resistance has arisen as the main downside in fighting bacterial infections pushing researchers to develop novel, more potent and multimodal alternative drugs.Silver and its complexes have long been used as antimicrobial agents in medicine due to the lack of silver resistance and the effectiveness at low concentration as well as to their low toxicities compared to the most commonly used antibiotics. N-Heterocyclic Carbenes (NHCs) have been extensively employed to coordinate transition metals mainly for catalytic chemistry. However, more recently, NHC ligands have been applied as carrier molecules for metals in anticancer applications. In the present study we selected from literature two NHC-carbene based on acridinescaffoldand detailed nonclassicalpyrazole derived mono NHC-Ag neutral and bis NHC-Ag cationic complexes. Their inhibitor effect on bacterial strains Gram-negative and positivewas evaluated. Imidazolium NHC silver complex containing the acridine chromophore showed effectiveness at extremely low MIC values. Although pyrazole NHC silver complexes are less active than the acridine NHC-silver, they represent the first example of this class of compounds with antimicrobial properties. Moreover all complexesare not toxic and they show not significant activity againstmammalian cells (Hek lines) after 4 and 24 h. Based on our experimental evidence, we are confident that this promising class of complexes could represent a valuable starting point for developing candidates for the treatment of bacterial infections, delivering great effectiveness and avoiding the development of resistance mechanisms.Funding Information
- Consiglio Nazionale delle Ricerche (Call CNR International joint laboratory - 2020 – 2022 Project-Saviano/Lobinski)
This publication has 32 references indexed in Scilit:
- Recent progress on NHC-stabilized early transition metal (group 3-7) complexes: Synthesis and applicationsCoordination Chemistry Reviews, 2020
- The Development and Catalytic Uses of N-Heterocyclic Carbene Gold ComplexesAccounts of Chemical Research, 2010
- Formation of Water-Soluble Pincer Silver(I)−Carbene Complexes: A Novel Antimicrobial AgentJournal of Medicinal Chemistry, 2004
- Syntheses, structures and antimicrobial activities of water-soluble silver(i)–oxygen bonding complexes with chiral and racemic camphanic acid (Hca) ligandsDalton Transactions, 2004
- Silver I: its antibacterial properties and mechanism of actionJournal of Wound Care, 2002
- On the Question of Stability, Conjugation, and “Aromaticity” in Imidazol-2-ylidenes and Their Silicon AnalogsJournal of the American Chemical Society, 1996
- Mechanism of Irreversible Inactivation of Phosphomannose Isomerases by Silver Ions and FlamazineBiochemistry, 1995
- 7 Antimicrobial Activity and Action of SilverProgress in Medicinal Chemistry, 1994
- A stable crystalline carbeneJournal of the American Chemical Society, 1991
- Treatment of Large Human Burns With 0.5% Silver Nitrate SolutionArchives of Surgery, 1965