title: Antimicrobial effects of short chained imidazolium-based ionic liquids—influence of anion chaotropicity.
abstract: Ionic liquids (ILs), a new solvent class composed solely of ions, have already found their way into numerous chemical and biochemical applications. Due to their unique properties and wide application range, research utilizing this new technology for biotechnological applications is steadily increasing. However, progress is hampered by lack of toxicological data, especially concerning IL anions and their general underlying toxicity mechanisms. The present study investigated for the first time the influence of the chaotropicity of the anion for nine imidazole based ILs on their antimicrobial behavior. The results indicate that for ILs with small cations ([C(n)mim](+) with n=2 and 4), the chaotropicity of the anion is a major factor regarding antimicrobial behavior, while for [C6mim](+) based ILs a surfactant-like behavior was identified that explains their high toxicity. It could also be shown that with increasing anion chaotropicity the surfactant-like behavior of the cation is strengthened. Identification of chaotropicity as an underlying mode of antimicrobial action of ILs presents a new point of adjustment for future design with regard to their toxicological behavior.
authors.affiliation: Christian Doppler Laboratory for Monitoring of Microbial Contaminants, Department of Veterinary Public Health and Food Science, University of Veterinary Medicine, Veterinaerplatz 1, 1210 Vienna, Austria.
authors.forename: Patrick
authors.initials: P
authors.lastname: Mester
authors.affiliation: Institute of Milk Hygiene, Milk Technology and Food Science, Department of Veterinary Public Health and Food Science, University of Veterinary Medicine, Veterinaerplatz 1, 1210 Vienna, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Wagner
authors.affiliation: Christian Doppler Laboratory for Monitoring of Microbial Contaminants, Department of Veterinary Public Health and Food Science, University of Veterinary Medicine, Veterinaerplatz 1, 1210 Vienna, Austria; Institute of Milk Hygiene, Milk Technology and Food Science, Department of Veterinary Public Health and Food Science, University of Veterinary Medicine, Veterinaerplatz 1, 1210 Vienna, Austria. Electronic address: peter.rossmanith@vetmeduni.ac.at.
authors.forename: Peter
authors.initials: P
authors.lastname: Rossmanith
mesh_terms: D000838:Anions / Q000737:chemistry; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000633:toxicity*; D002412:Cations / Q000737:chemistry; D007093:Imidazoles / Q000737:chemistry* / Q000633:toxicity*; D052578:Ionic Liquids / Q000737:chemistry* / Q000633:toxicity*; D013501:Surface-Active Agents / Q000737:chemistry / Q000633:toxicity
chemical_list: D000838:Anions; D000900:Anti-Bacterial Agents; D002412:Cations; D007093:Imidazoles; D052578:Ionic Liquids; D013501:Surface-Active Agents
keywords: Antimicrobials; Escherichia coli; Hofmeister effects; Ionic liquids; Listeria monocytogenes; Toxicity