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Nunes B, Cagide F, Fernandes C, Borges A, Borges F, Simões M. Efficacy of Novel Quaternary Ammonium and Phosphonium Salts Differing in Cation Type and Alkyl Chain Length against Antibiotic-Resistant Staphylococcus aureus. Int J Mol Sci 2023; 25:504. [PMID: 38203676 PMCID: PMC10778626 DOI: 10.3390/ijms25010504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 12/22/2023] [Accepted: 12/27/2023] [Indexed: 01/12/2024] Open
Abstract
Antibacterial resistance poses a critical public health threat, challenging the prevention and treatment of bacterial infections. The search for innovative antibacterial agents has spurred significant interest in quaternary heteronium salts (QHSs), such as quaternary ammonium and phosphonium compounds as potential candidates. In this study, a library of 49 structurally related QHSs was synthesized, varying the cation type and alkyl chain length. Their antibacterial activities against Staphylococcus aureus, including antibiotic-resistant strains, were evaluated by determining minimum inhibitory/bactericidal concentrations (MIC/MBC) ≤ 64 µg/mL. Structure-activity relationship analyses highlighted alkyl-triphenylphosphonium and alkyl-methylimidazolium salts as the most effective against S. aureus CECT 976. The length of the alkyl side chain significantly influenced the antibacterial activity, with optimal chain lengths observed between C10 and C14. Dose-response relationships were assessed for selected QHSs, showing dose-dependent antibacterial activity following a non-linear pattern. Survival curves indicated effective eradication of S. aureus CECT 976 by QHSs at low concentrations, particularly compounds 1e, 3e, and 5e. Moreover, in vitro human cellular data indicated that compounds 2e, 4e, and 5e showed favourable safety profiles at concentrations ≤ 2 µg/mL. These findings highlight the potential of these QHSs as effective agents against susceptible and resistant bacterial strains, providing valuable insights for the rational design of bioactive QHSs.
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Affiliation(s)
- Bárbara Nunes
- LEPABE—Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal; (B.N.); (A.B.)
- ALiCE—Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
- CIQUP-IMS, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal (C.F.); (F.B.)
| | - Fernando Cagide
- CIQUP-IMS, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal (C.F.); (F.B.)
| | - Carlos Fernandes
- CIQUP-IMS, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal (C.F.); (F.B.)
| | - Anabela Borges
- LEPABE—Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal; (B.N.); (A.B.)
- ALiCE—Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Fernanda Borges
- CIQUP-IMS, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal (C.F.); (F.B.)
| | - Manuel Simões
- LEPABE—Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal; (B.N.); (A.B.)
- ALiCE—Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
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Petit M, Tessier J, Sahli C, Schmitzer AR. Confronting the Threat: Designing Highly Effective bis-Benzimidazolium Agents to Overcome Biofilm Persistence and Antimicrobial Resistance. ACS Infect Dis 2023; 9:2202-2214. [PMID: 37882623 DOI: 10.1021/acsinfecdis.3c00289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2023]
Abstract
The objective of this study is to take the initial steps toward developing novel antibiotics to counteract the escalating problem of antimicrobial and bacterial persistence, particularly in relation to biofilms. Our approach involves emulating the structural characteristics of cationic antimicrobial peptides. To circumvent resistance development, we have designed a library of bis-benzimidazolium salts that selectively target the microbial membranes in a nonspecific manner. To explore their structure-activity relationship, we conducted experiments using these compounds on various pathogens known for their resistance to conventional antibiotics, including Gram-positive methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium (VRE), and Gram-negative Escherichia coli (E. coli). Notably, two bis-benzimidazolium salts exhibited robust antimicrobial activity while maintaining a high level of selectivity compared with mammalian cells. Our investigations revealed significant antibiofilm activity, as these compounds rapidly acted against established biofilms. In addition, bis-benzimidazolium compounds exhibited consistent results in resistance development and cross-resistance studies. Consequently, amphiphilic bis-benzimidazolium salts hold promise as potential candidates to combat resistance-associated infections.
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Affiliation(s)
- Maude Petit
- Département de Chimie, Faculté des Arts et des Sciences, Université de Montréal, Campus MIL, 1375, Ave. Thérèse Lavoie-Roux, Montréal, Québec H2 V 0B3, Canada
| | - Jérémie Tessier
- Département de Chimie, Faculté des Arts et des Sciences, Université de Montréal, Campus MIL, 1375, Ave. Thérèse Lavoie-Roux, Montréal, Québec H2 V 0B3, Canada
- Collège Bois-de-Boulogne, 10555 Ave. de Bois-de-Boulogne, Montréal H4N 1L4, Canada
| | - Célia Sahli
- Département de Chimie, Faculté des Arts et des Sciences, Université de Montréal, Campus MIL, 1375, Ave. Thérèse Lavoie-Roux, Montréal, Québec H2 V 0B3, Canada
- CNRS-UMR 7086, Interfaces, Traitements, Organisation et Dynamique des Systèmes (ITODYS), Université Paris Cité, Paris 75013 , France
| | - Andreea R Schmitzer
- Département de Chimie, Faculté des Arts et des Sciences, Université de Montréal, Campus MIL, 1375, Ave. Thérèse Lavoie-Roux, Montréal, Québec H2 V 0B3, Canada
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Putralis R, Korotkaja K, Kaukulis M, Rudevica Z, Jansons J, Nilova O, Rucins M, Krasnova L, Domracheva I, Plotniece M, Pajuste K, Sobolev A, Rumnieks F, Bekere L, Zajakina A, Plotniece A, Duburs G. Styrylpyridinium Derivatives for Fluorescent Cell Imaging. Pharmaceuticals (Basel) 2023; 16:1245. [PMID: 37765053 PMCID: PMC10535741 DOI: 10.3390/ph16091245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 08/25/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
A set of styrylpyridinium (SP) compounds was synthesised in order to study their spectroscopic and cell labelling properties. The compounds comprised different electron donating parts (julolidine, p-dimethylaminophenyl, p-methoxyphenyl, 3,4,5-trimethoxyphenyl), conjugated linkers (vinyl, divinyl), and an electron-withdrawing N-alkylpyridinium part. Geminal or bis-compounds incorporating two styrylpyridinium (bis-SP) moieties at the 1,3-trimethylene unit were synthesised. Compounds comprising a divinyl linker and powerful electron-donating julolidine donor parts possessed intensive fluorescence in the near-infrared region (maximum at ~760 nm). The compounds had rather high cytotoxicity towards the cancerous cell lines HT-1080 and MH-22A; at the same time, basal cytotoxicity towards the NIH3T3 fibroblast cell line ranged from toxic to harmful. SP compound 6e had IC50 values of 1.0 ± 0.03 µg/mL to the cell line HT-1080 and 0.4 µg/mL to MH-22A; however, the basal toxicity LD50 was 477 mg/kg (harmful). The compounds showed large Stokes' shifts, including 195 nm for 6a,b, 240 nm for 6e, and 325 and 352 nm for 6d and 6c, respectively. The highest photoluminescence quantum yield (PLQY) values were observed for 6a,b, which were 15.1 and 12.2%, respectively. The PLQY values for the SP derivatives 6d,e (those with a julolidinyl moiety) were 0.5 and 0.7%, respectively. Cell staining with compound 6e revealed a strong fluorescent signal localised in the cell cytoplasm, whereas the cell nuclei were not stained. SP compound 6e possessed self-assembling properties and formed liposomes with an average diameter of 118 nm. The obtained novel data on near-infrared fluorescent probes could be useful for the development of biocompatible dyes for biomedical applications.
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Affiliation(s)
- Reinis Putralis
- Latvian Institute of Organic Synthesis, LV-1006 Riga, Latvia; (R.P.); (M.K.); (M.R.); (L.K.); (I.D.); (K.P.); (A.S.); (L.B.)
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Riga Stradiņš University, LV-1007 Riga, Latvia;
| | - Ksenija Korotkaja
- Latvian Biomedical Research and Study Centre, LV-1067 Riga, Latvia; (K.K.); (Z.R.); (J.J.); (O.N.); (F.R.); (A.Z.)
| | - Martins Kaukulis
- Latvian Institute of Organic Synthesis, LV-1006 Riga, Latvia; (R.P.); (M.K.); (M.R.); (L.K.); (I.D.); (K.P.); (A.S.); (L.B.)
- Faculty of Materials Science and Applied Chemistry, Riga Technical University, LV-1048 Riga, Latvia
| | - Zhanna Rudevica
- Latvian Biomedical Research and Study Centre, LV-1067 Riga, Latvia; (K.K.); (Z.R.); (J.J.); (O.N.); (F.R.); (A.Z.)
| | - Juris Jansons
- Latvian Biomedical Research and Study Centre, LV-1067 Riga, Latvia; (K.K.); (Z.R.); (J.J.); (O.N.); (F.R.); (A.Z.)
| | - Olga Nilova
- Latvian Biomedical Research and Study Centre, LV-1067 Riga, Latvia; (K.K.); (Z.R.); (J.J.); (O.N.); (F.R.); (A.Z.)
| | - Martins Rucins
- Latvian Institute of Organic Synthesis, LV-1006 Riga, Latvia; (R.P.); (M.K.); (M.R.); (L.K.); (I.D.); (K.P.); (A.S.); (L.B.)
| | - Laura Krasnova
- Latvian Institute of Organic Synthesis, LV-1006 Riga, Latvia; (R.P.); (M.K.); (M.R.); (L.K.); (I.D.); (K.P.); (A.S.); (L.B.)
| | - Ilona Domracheva
- Latvian Institute of Organic Synthesis, LV-1006 Riga, Latvia; (R.P.); (M.K.); (M.R.); (L.K.); (I.D.); (K.P.); (A.S.); (L.B.)
| | - Mara Plotniece
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Riga Stradiņš University, LV-1007 Riga, Latvia;
- Faculty of Materials Science and Applied Chemistry, Riga Technical University, LV-1048 Riga, Latvia
| | - Karlis Pajuste
- Latvian Institute of Organic Synthesis, LV-1006 Riga, Latvia; (R.P.); (M.K.); (M.R.); (L.K.); (I.D.); (K.P.); (A.S.); (L.B.)
| | - Arkadij Sobolev
- Latvian Institute of Organic Synthesis, LV-1006 Riga, Latvia; (R.P.); (M.K.); (M.R.); (L.K.); (I.D.); (K.P.); (A.S.); (L.B.)
| | - Felikss Rumnieks
- Latvian Biomedical Research and Study Centre, LV-1067 Riga, Latvia; (K.K.); (Z.R.); (J.J.); (O.N.); (F.R.); (A.Z.)
| | - Laura Bekere
- Latvian Institute of Organic Synthesis, LV-1006 Riga, Latvia; (R.P.); (M.K.); (M.R.); (L.K.); (I.D.); (K.P.); (A.S.); (L.B.)
| | - Anna Zajakina
- Latvian Biomedical Research and Study Centre, LV-1067 Riga, Latvia; (K.K.); (Z.R.); (J.J.); (O.N.); (F.R.); (A.Z.)
| | - Aiva Plotniece
- Latvian Institute of Organic Synthesis, LV-1006 Riga, Latvia; (R.P.); (M.K.); (M.R.); (L.K.); (I.D.); (K.P.); (A.S.); (L.B.)
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Riga Stradiņš University, LV-1007 Riga, Latvia;
| | - Gunars Duburs
- Latvian Institute of Organic Synthesis, LV-1006 Riga, Latvia; (R.P.); (M.K.); (M.R.); (L.K.); (I.D.); (K.P.); (A.S.); (L.B.)
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Bogdanov A, Voloshina AD, Sapunova AS, Kulik NV, Bukharov SV, Dobrynin AB, Voronina JK, Terekhova NV, Samorodov AV, Pavlov VN, Mironov VF. Isatin-3-acylhydrazones with enhanced lipophilicity: synthesis, antimicrobial activity evaluation and the influence on hemostasis system. Chem Biodivers 2021; 19:e202100496. [PMID: 34958705 DOI: 10.1002/cbdv.202100496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 12/27/2021] [Indexed: 11/06/2022]
Abstract
Water-soluble trialkylammonium isatin-3-hydrazone derivatives bearing hydroxybenzyl substituent were easily synthesized with high yields. XRD studies confirmed the presence of these compounds as trans-( Z )-isomers in a crystal. It was shown that an increase in the lipophilicity of the cationic center leads to an increase in activity against Gram-positive bacteria Staphylococcus aureus and Bacillus cereus, including methicillin-resistant (MRSA) strains. The MIC values of the leading compounds turned out to be 2-100 times higher than the MIC of norfloxacin against the MRSA strains in the absence of hemo- and cytotoxicity. Antiaggregation and anticoagulation properties were in vitro better than for acetylsalicylic acid and sodium heparin drugs. It has been shown by UV spectroscopy and fluorescence microscopy that the mechanism of antimicrobial action of new acylhydrazones is associated with their ability to destroy the bacterial cell membrane.
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Affiliation(s)
- Andrei Bogdanov
- A.E.Arbuzov Institute of organic and physical chemistry of the Russian academy of sciences, laboratory of phosphorus-containing analogues of natural compounds, Arbuzov str., 8, Not Available, 420088, Kazan, RUSSIAN FEDERATION
| | - Alexandra D Voloshina
- Arbuzov Institute of Organic and Physical Chemistry FRC Kazan Scientific Center of Russian Academy of Sciences: Institut organicheskoj i fizicheskoj khimii imeni A E Arbuzova KazNC RAN, Laboratory of microbiology, Arbuzov str., 8, Kazan, RUSSIAN FEDERATION
| | - Anastasia S Sapunova
- Arbuzov Institute of Organic and Physical Chemistry FRC Kazan Scientific Center of Russian Academy of Sciences: Institut organicheskoj i fizicheskoj khimii imeni A E Arbuzova KazNC RAN, Laboratory of microbiology, Arbuzov str., 8, Kazan, RUSSIAN FEDERATION
| | - Natalia V Kulik
- Arbuzov Institute of Organic and Physical Chemistry FRC Kazan Scientific Center of Russian Academy of Sciences: Institut organicheskoj i fizicheskoj khimii imeni A E Arbuzova KazNC RAN, Laboratory of microbiology, Arbuzov str., 8, Kazan, RUSSIAN FEDERATION
| | - Sergey V Bukharov
- Kazan National Research Technological University: Kazanskij nacional'nyj issledovatel'skij tehnologiceskij universitet, TOONS, Marx str., 32, Kazan, RUSSIAN FEDERATION
| | - Alexey B Dobrynin
- Arbuzov Institute of Organic and Physical Chemistry FRC Kazan Scientific Center of Russian Academy of Sciences: Institut organicheskoj i fizicheskoj khimii imeni A E Arbuzova KazNC RAN, Laboratory of diffraction analysis, Arbuzov str., 8, Kazan, RUSSIAN FEDERATION
| | - Julia K Voronina
- Kurnakov Institute of General and Inorganic Chemistry RAS: Institut obsej i neorganiceskoj himii imeni N S Kurnakova RAN, Inorganic X-Ray, Leninskiy prosp., 31, Moscow, RUSSIAN FEDERATION
| | - Natalia V Terekhova
- Arbuzov Institute of Organic and Physical Chemistry FRC Kazan Scientific Center of Russian Academy of Sciences: Institut organicheskoj i fizicheskoj khimii imeni A E Arbuzova KazNC RAN, PCANC Laboratory, Arbuzov str., 8, Kazan, RUSSIAN FEDERATION
| | - Alexander V Samorodov
- Bashkir State Medical University: Baskirskij gosudarstvennyj medicinskij universitet, Clinical laboratory, Lenin str, 3, Ufa, RUSSIAN FEDERATION
| | - Valentin N Pavlov
- Bashkir State Medical University: Baskirskij gosudarstvennyj medicinskij universitet, Clinical laboratory, Lenin str, 3, Ufa, RUSSIAN FEDERATION
| | - Vladimir F Mironov
- Arbuzov Institute of Organic and Physical Chemistry FRC Kazan Scientific Center of Russian Academy of Sciences: Institut organicheskoj i fizicheskoj khimii imeni A E Arbuzova KazNC RAN, PCANC laboratory, Arbuzov str., 8, Kazan, RUSSIAN FEDERATION
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Morandini A, Spadati E, Leonetti B, Sole R, Gatto V, Rizzolio F, Beghetto V. Sustainable triazine-derived quaternary ammonium salts as antimicrobial agents. RSC Adv 2021; 11:28092-28096. [PMID: 35480717 PMCID: PMC9038131 DOI: 10.1039/d1ra03455c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 08/15/2021] [Indexed: 12/23/2022] Open
Abstract
The first examples of highly efficient antimicrobial triazine-derived bis imidazolium quaternary ammonium salts (TQAS) are reported. TQAS have been prepared with an easy, atom efficient, economically sustainable strategy and tested as antimicrobial agents, reaching MIC values below 10 mg L-1. Distinctively, TQAS have low MIC and low cytotoxicity.
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Affiliation(s)
- Andrea Morandini
- Università Ca' Foscari di Venezia Via Torino 155 Venezia Mestre 30172 Italy
| | - Emanuele Spadati
- Università Ca' Foscari di Venezia Via Torino 155 Venezia Mestre 30172 Italy
| | - Benedetta Leonetti
- Brenta S.r.l. - Nine Trees Group. Viale Milano, 26 36075 Montecchio Maggiore Vicenza Italy
| | - Roberto Sole
- Università Ca' Foscari di Venezia Via Torino 155 Venezia Mestre 30172 Italy .,Consorzio Interuniversitario per le Reattività Chimiche e Catalisi (CIRCC) Via C. Ulpiani 27 70126 Bari Italy
| | - Vanessa Gatto
- Crossing S.r.l. Viale della Repubblica 193/b Treviso 31100 Italy
| | - Flavio Rizzolio
- Università Ca' Foscari di Venezia Via Torino 155 Venezia Mestre 30172 Italy
| | - Valentina Beghetto
- Università Ca' Foscari di Venezia Via Torino 155 Venezia Mestre 30172 Italy .,Crossing S.r.l. Viale della Repubblica 193/b Treviso 31100 Italy
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Vereshchagin AN, Frolov NA, Egorova KS, Seitkalieva MM, Ananikov VP. Quaternary Ammonium Compounds (QACs) and Ionic Liquids (ILs) as Biocides: From Simple Antiseptics to Tunable Antimicrobials. Int J Mol Sci 2021; 22:6793. [PMID: 34202677 PMCID: PMC8268321 DOI: 10.3390/ijms22136793] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/15/2021] [Accepted: 06/16/2021] [Indexed: 12/13/2022] Open
Abstract
Quaternary ammonium compounds (QACs) belong to a well-known class of cationic biocides with a broad spectrum of antimicrobial activity. They are used as essential components in surfactants, personal hygiene products, cosmetics, softeners, dyes, biological dyes, antiseptics, and disinfectants. Simple but varied in their structure, QACs are divided into several subclasses: Mono-, bis-, multi-, and poly-derivatives. Since the beginning of the 20th century, a significant amount of work has been dedicated to the advancement of this class of biocides. Thus, more than 700 articles on QACs were published only in 2020, according to the modern literature. The structural variability and diverse biological activity of ionic liquids (ILs) make them highly prospective for developing new types of biocides. QACs and ILs bear a common key element in the molecular structure-quaternary positively charged nitrogen atoms within a cyclic or acyclic structural framework. The state-of-the-art research level and paramount demand in modern society recall the rapid development of a new generation of tunable antimicrobials. This review focuses on the main QACs exhibiting antimicrobial and antifungal properties, commercial products based on QACs, and the latest discoveries in QACs and ILs connected with biocide development.
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Affiliation(s)
- Anatoly N. Vereshchagin
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, 119991 Moscow, Russia; (N.A.F.); (K.S.E.); (M.M.S.)
| | | | | | | | - Valentine P. Ananikov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, 119991 Moscow, Russia; (N.A.F.); (K.S.E.); (M.M.S.)
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The wide-spectrum antimicrobial effect of novel N-alkyl monoquaternary ammonium salts and their mixtures; the QSAR study against bacteria. Eur J Med Chem 2020; 206:112584. [PMID: 32853858 DOI: 10.1016/j.ejmech.2020.112584] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 05/05/2020] [Accepted: 06/14/2020] [Indexed: 11/23/2022]
Abstract
Quaternary ammonium salts (QASs) have been widely used for disinfection purposes because of their low price, high efficacy and low human toxicity for decades. However, precise mechanisms of action nor the powerful versatile agent against all antimicrobial species are known. In this study we have prepared 43 novel N-alkyl monoquaternary ammonium salts including 7 N,N-dialkyl monoquaternary ammonium salts differing bearing alkyl chain either of 12, 14 or 16 carbons. Together with 15 already published QASs we have studied the antimicrobial efficacy of all water-soluble compounds together with standard benzalkonium salts against Gram-positive (G+) and Gram-negative (G-) bacteria, anaerobic spore-forming Cl. difficile, yeasts, filamentous fungi and enveloped Varicella zoster virus (VZV). To address the mechanism of action, lipophilicity seems to be a key parameter which determines antimicrobial efficacy, however, exceptions are likely to occur and therefore QSAR analysis on the efficacy against G+ and G- bacteria was applied. We showed that antibacterial activity is higher when the molecule is larger, more lipophilic, less polar, and contains fewer oxygen atoms, fewer methyl groups bound to heteroatoms or fewer hydrogen atoms bound to polarized carbon atoms. In addition, from an application point of view, we have formulated mixtures, on the basis of obtained efficiency of individual compounds, in order to receive wide-spectrum agent. All formulated mixtures completely eradicated tested G+ and G- strains, including the multidrug-resistant P. aeruginosa as well as in case of yeasts. However, effect on A. fumigatus, Cl. difficile and VZV the exposition towards mixture resulted in significant reduction only. Finally, 3 out of 4 formulated mixtures were safer than reference commercial agent based on benzalkonium salts only in the skin irritation test using reconstructed human epidermidis.
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