title: Different antibacterial activity of novel theophylline-based ionic liquids - Growth kinetic and cytotoxicity studies.
abstract: The aim of this study was to investigate novel theophylline-based ionic liquids and their cytotoxic effects towards model Gram-positive and Gram-negative bacteria (Bacillus cereus and Escherichia coli, respectively). Growth kinetics, respiratory rates and dehydrogenase activities were studied in the presence of ionic liquids at concentrations ranging from 10 to 1000mg/L. Additionally, the influence of ionic liquids on bacterial cells associated with specific interactions based on the structure of cell wall was evaluated. This effect was assessed by viability tests and scanning electron microscope observations. The obtained results confirmed that ionic liquids exhibit different levels of toxicity in relation to Gram-positive and Gram-negative bacteria. Those effects are associated with the chemical structure of the cationic species of the ionic liquids and their critical micelle concentration value. It was established that the presence of an alkyl or allyl group increased the toxicity, whereas the presence of an aryl group in the cation decreased the toxic effect of ILs. Results presented in this study also revealed unexpected effects of self-aggregation of E. coli cells. Overall, it was established that the studied ILs exhibited higher toxicity towards Gram-positive bacteria due to different interactions between the ILs and the cell membranes. These findings may be of importance for the design of ILs with targeted antimicrobial properties.
authors.affiliation: Faculty of Geology, University of Warsaw, Żwirki i Wigury 93, 02-089 Warsaw, Poland. Electronic address: a.borkowski@uw.edu.pl.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Borkowski
authors.affiliation: Faculty of Chemical Technology, Poznan University of Technology, M. Skłodowskiej-Curie 2, 60-965 Poznan, Poland.
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Ławniczak
authors.affiliation: Department of General and Environmental Microbiology, Poznan University of Life Sciences, Szydłowska 50, 60-656 Poznan, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Cłapa
authors.affiliation: Department of Biochemistry and Biotechnology, Poznan University of Life Sciences, Dojazd 11, 60-632 Poznan, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Narożna
authors.affiliation: Department of General and Environmental Microbiology, Poznan University of Life Sciences, Szydłowska 50, 60-656 Poznan, Poland.
authors.forename: Marek
authors.initials: M
authors.lastname: Selwet
authors.affiliation: Faculty of Chemical Technology, Poznan University of Technology, M. Skłodowskiej-Curie 2, 60-965 Poznan, Poland.
authors.forename: Daria
authors.initials: D
authors.lastname: Pęziak
authors.affiliation: Faculty of Chemical Technology, Poznan University of Technology, M. Skłodowskiej-Curie 2, 60-965 Poznan, Poland.
authors.forename: Bartosz
authors.initials: B
authors.lastname: Markiewicz
authors.affiliation: Faculty of Chemical Technology, Poznan University of Technology, M. Skłodowskiej-Curie 2, 60-965 Poznan, Poland.
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Chrzanowski
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D001409:Bacillus cereus / Q000187:drug effects* / Q000502:physiology*; D002412:Cations / Q000737:chemistry / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects* / Q000502:physiology*; D052578:Ionic Liquids / Q000737:chemistry / Q000494:pharmacology; D008823:Micelles; D008826:Microbial Sensitivity Tests; D010088:Oxidoreductases / Q000187:drug effects / Q000378:metabolism; D013806:Theophylline / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D002412:Cations; D052578:Ionic Liquids; D008823:Micelles; D013806:Theophylline; D010088:Oxidoreductases
keywords: Bacillus cereus; Escherichia coli; Ionic liquids; Theophylline; Toxicity