ABSTRACT
[This corrects the article DOI: 10.1371/journal.pone.0228525.].
ABSTRACT
The toxic effect of strained hydrocarbon 2,2'-bis (bicyclo[2.2.1]heptane) (BBH) was studied using whole-cell bacterial lux-biosensors based on Escherichia coli cells in which luciferase genes are transcriptionally fused with stress-inducible promoters. It was shown that BBH has the genotoxic effect causing bacterial SOS response however no alkylating effect has been revealed. In addition to DNA damage, there is an oxidative effect causing the response of OxyR/S and SoxR/S regulons. The most sensitive to BBH lux-biosensor was E. coli pSoxS-lux which reacts to the appearance of superoxide anion radicals in the cell. It is assumed that the oxidation of BBH leads to the generation of reactive oxygen species, which provide the main contribution to the genotoxicity of this substance.
Subject(s)
Bridged Bicyclo Compounds/toxicity , Escherichia coli/drug effects , Escherichia coli/genetics , Mutagens/toxicity , Alkylation/drug effects , Biosensing Techniques , DNA Damage , Dose-Response Relationship, Drug , Escherichia coli/cytology , Escherichia coli/metabolism , Oxidative Stress/drug effects , Regulon/drug effects , Regulon/geneticsABSTRACT
Enthalpy and entropy of adsorption of polar and non-polar solutes were measured by chromatographic technique for new stationary phases prepared from membrane polymers based on tricyclonones. Data obtained within temperature interval from 40 to 150⯰C were used to create extrathermodynamic dependences (compensation plots, dependences of enthalpy and entropy changes on solute carbon number). Compensation plots were very similar for all the stationary phases indicating similar adsorption mechanisms. The difference between the stationary phases was elucidated using dependences of enthalpy and entropy changes on solute carbon number. Higher retentivity of the stationary phase based on polymer 1 was explained by higher both enthalpy and entropy of solute adsorption on the stationary phase.
Subject(s)
Chemistry Techniques, Analytical/methods , Hydrocarbons/chemistry , Polymers/chemistry , Adsorption , Chromatography , Entropy , Temperature , ThermodynamicsABSTRACT
Norbornene polymers with intrinsic porosity were investigated as candidates for polymeric stationary phases in capillary GC. Kinetic and thermodynamic characteristics of the stationary phases were evaluated and turned out that only polymer with vicinal distribution of trimethylsilyl groups (polymer II) provided properties making it potential candidate for application in capillary GC. Columns with stationary phase based on polymer II demonstrated unique selectivity, moderate thermostability and efficiency better than previously studied columns with stationary phase based on poly[(1-trimethylsilyl)-1-propine].