Uptake of (14)C-labeled fluoranthene ([(14)C]FLT) via both roots and leaves of Pisum sativum seedlings and distribution of [(14) C] in plants by both acropetal and basipetal transport was evaluated. The highest [(14)C] level was found in the root base (≈270 × 10(4) dpm/g dry wt) and the lowest level in the stem apex (<2 × 10(4) dpm/g dry wt) after just 2 h of root exposure. For foliar uptake, the highest level of [(14)C] was found in the stem and root apex (both ≈2 × 10(4) dpm/g dry wt) (except for treated leaves), while the lowest level was found in the root base (<0.6 × 10(4) dpm/g dry wt).
- MeSH
- biologický transport MeSH
- fluoreny analýza metabolismus MeSH
- hrách setý metabolismus MeSH
- kořeny rostlin metabolismus MeSH
- látky znečišťující životní prostředí analýza metabolismus MeSH
- listy rostlin metabolismus MeSH
- monitorování životního prostředí MeSH
- radioizotopy uhlíku analýza metabolismus MeSH
- stonky rostlin metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Optimum conditions were found for the determination of nanomolar and subnanomolar concentrations of genotoxic 2-aminofluoren-9-one (2-AFN) by adsorptive stripping differential pulse voltammetry (AdSDPV) at a hanging mercury drop minielectrode (HMDmE) after preliminary separation and preconcentration by solidphase extraction (SPE) in LiChrolut RP-18 E (500 mg) columns. The adsorbed analyte was eluted with acetone, the solution then evaporated to dryness, and the residue dissolved in acetate buffer (pH 4.0) (AcB). A sample was then measured by AdSDPV at the HMDmE, with the accumulation potential 100 mV (vs. Ag|AgCl in 1 mol l–1 KCl) and the accumulation time 120 s. Linear calibration curves were obtained for 2·10–11 – 1·10–9 mol l–1 2-AFN, with the limit of quantification (LQ) ≈ 4·10–11 mol l–1. The method was verified by the determination of 2-AFN in model samples of drinking and river water at concentrations 4·10–11 – 1·10–9 and 2·10–10 – 1·10–9 mol l–1 (LQ ≈ 6·10–11 and 4·10–10 mol l–1, respectively).
- MeSH
- chemické znečištění vody * MeSH
- elektrochemické techniky * metody přístrojové vybavení využití MeSH
- fluoreny analýza MeSH
- indikátory a reagencie * MeSH
- pitná voda MeSH
- polarografie * metody přístrojové vybavení využití MeSH
- polycyklické aromatické uhlovodíky * škodlivé účinky toxicita MeSH
- vodní hospodářství MeSH
- Publikační typ
- práce podpořená grantem MeSH
Polycyclic aromatic hydrocarbons (PAHs) represent one of the major groups of organic contaminants in the aquatic environment. Duckweed (Lemna minor L.) is a common aquatic plant widely used in phytotoxicity tests for xenobiotic substances. The goal of this study was to assess the growth and the physiological, biochemical and histochemical changes in duckweed exposed for 4 and 10 days to fluoranthene (FLT, 0.1 and 1 mgL(-1)). Nonsignificant changes in number of plants, biomass production, leaf area size, content of chlorophylls a and b and carotenoids and parameters of chlorophyll fluorescence recorded after 4 and 10 days of exposure to FLT were in contrast with considerable changes at biochemical and histochemical levels. Higher occurrence of reactive oxygen species (ROS) caused by an exposure to FLT after 10 days as compared to control (hydrogen peroxide elevated by 13% in the 0.1 mgL(-1) and by 41% in the 1 mgL(-1) FLT; superoxide anion radical by 52% and 115% respectively) reflected in an increase in the activities of antioxidant enzymes (superoxide dismutase by 3% in both treatments, catalase by 9% and 1% respectively, ascorbate peroxidase by 21% and 5% respectively, guaiacol peroxidase by 12% in the 0.1 mgL(-1) FLT). Even the content of antioxidant compounds like ascorbate (by 20% in the 1 mgL(-1) FLT) or total thiols (reduced forms by 15% in the 0.1 mgL(-1) and 8% in the 1 mgL(-1) FLT, oxidized forms by 36% in the 0.1 mgL(-1) FLT) increased. Increased amount of ROS was followed by an increase in malondialdehyde content (by 33% in the 0.1 mgL(-1) and 79% in the 1 mgL(-1) FLT). Whereas in plants treated by the 0.1 mgL(-1) FLT the contents of total proteins and phenols increased by 15% and 25%, respectively, the 1 mgL(-1) FLT caused decrease of their contents by 32% and 7%. Microscopic observations of duckweed roots also confirmed the presence of ROS and related histochemical changes at the cellular and tissue levels. The assessment of phytotoxicity of organic pollutant in duckweed based only on the evaluation of growth parameters could not fully cover the irreversible changes already running at the level of biochemical processes.
- MeSH
- Araceae účinky léků růst a vývoj MeSH
- biologické pigmenty metabolismus MeSH
- biomasa MeSH
- časové faktory MeSH
- chemické látky znečišťující vodu toxicita MeSH
- fluoreny analýza toxicita MeSH
- peroxidace lipidů účinky léků MeSH
- reaktivní formy kyslíku metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Electrochemical behavior of genotoxic 2,7-dinitrofluoren-9-one was investigated by DC polarography and DC tast polarography, both at a dropping mercury electrode, and by cyclic voltammetry at a hanging mercury drop electrode, in buffered aqueous-methanolic solutions. The number of exchanged electrons was determined by constant-potential coulometry at a mercury pool electrode. A possible mechanism of the electrochemical reduction has been proposed. Optimal conditions were found for the determination of 2,7-dinitrofluoren-9-one by DC tast polarography in the concentration range from 2 × 10–6 to 1 × 10–5 mol l–1 and by differential pulse polarography (from 2 × 10–7 to 1 × 10–5 mol l–1), both at dropping mercury electrode, by differential pulse voltammetry (from 2 × 10–8 to 1 × 10–5 mol l–1) and by adsorptive stripping voltammetry (from 2 × 10–9 to 1 × 10–7 mol l–1), both at hanging mercury drop electrode. Practical applicability of the developed methods was verified on the direct determination of 2,7-dinitrofluoren-9-one in drinking water in 10–8 mol l–1 concentration range, and in drinking and river water (both in 10–9 mol l–1 concentration range) using preliminary separation and preconcentration by solid-phase extraction.
Benfluron (B) [5-(2-dimethylaminoethoxy)-7H-benzo[c]fluorene-7-one hydrochloride] is a potential antineoplastic agent. In the organism, B undergoes a rapid phase I biotransformation through oxidative and reductive metabolic pathways. The carbonyl reduction of B leads to reduced benfluron, red-B, this is one of the principal pathways for the deactivation of this compound. The structure of B was modified to suppress its rapid deactivation via the carbonyl reduction on C7. Dimefluron, D (3,9-dimethoxy-benfluron) is one of the derivatives of B, in which an alternative metabolic pathway (O-desmethylation) prevails over the carbonyl reduction. The goal of this study was to develop HPLC methods enabling chiral separations of the red-B and -D enantiomers. The separation of red-B enantiomers was successful done on a Chiralcel OD-R column (250 mm x 4.6 mm ID, 5 microm) using a mobile phase acetonitrile-1 M NaClO4 (40:60, v/v). Another mobile phase, methanol-1 M NaClO4 (75:25, v/v), had to be employed for the sufficient resolution of red-D enantiomers. Flow rate was 0.5 ml min(-1) in both cases. Red-B was detected at 340 nm, red-D at 370 nm. The above chiral HPLC methods were used for the study of the biotransformation of B and D in the microsomal fractions of liver homogenates prepared from various species (rat, rabbit, pig, guinea pig, goat and human). The enantiospecificity of the respective carbonyl reductases was evaluated and discussed for both prochiral compounds, B and D.
- MeSH
- alkoholoxidoreduktasy metabolismus MeSH
- antitumorózní látky analýza metabolismus MeSH
- chromatografie kapalinová metody MeSH
- druhová specificita MeSH
- financování organizované MeSH
- fluoreny analýza metabolismus MeSH
- hospodářská zvířata MeSH
- játra chemie metabolismus MeSH
- králíci MeSH
- krysa rodu rattus MeSH
- lidé středního věku MeSH
- lidé MeSH
- molekulární konformace MeSH
- morčata MeSH
- potkani Wistar MeSH
- preklinické hodnocení léčiv metody MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- krysa rodu rattus MeSH
- lidé středního věku MeSH
- lidé MeSH
- morčata MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- srovnávací studie MeSH
The disposition of a new potential antineoplastic drug dimefluron after an oral administration to rats was investigated. Dimefluron, 3,9-dimethoxy-5-(2-dimethylaminoethoxy)-7H-benzo[c]fluoren-7-one hydrochloride, was administered in a single oral dose (250 mg kg(-1) of body weight) in the form of an aqueous solution via a gastric probe. Dimefluron metabolites were being searched for in rat faeces. Synthetic standards of the expected phase I metabolites (the products of O- and N-desmethylation, N-oxidation and carbonyl reduction of dimefluron) were prepared and used together with dimefluron and internal standard in the development of two HPLC bioanalytical methods based on different separation principles. The first separation of dimefluron and the phase I metabolites was tested on a 250 mm x 4 mm chromatographic column with LiChrospher 60 RP-selectB 5 microm (Merck) using an isocratic mobile phase containing 0.01 M nonylamine buffer (pH 7.4) and acetonitrile in the 1:2 ratio (v/v). The second separation was performed on a 250 mm x 4 mm chromatographic column Discovery HS F5, 5 microm (Supelco) using a linear gradient mode with the mobile phase containing acetonitrile and phosphate buffer (0.05 M KH2PO4, pH 3). The flow rate was 1 ml min(-1) in both cases. UV detection was performed in the dual wavelength mode, with 317 nm having been used for dimefluron and all 7H-benzo[c]fluoren-7-one metabolites, 367 nm for 7H-benzo[c]fluoren-7-ol metabolites. A higher homologue of dimefluron served as an internal standard. The identity of the dimefluron metabolites in biological samples was confirmed using HPLC-MS experiments. The elimination study showed that the concentration maximum for dimefluron and its metabolites in rat faeces was reached 48 h after the administration of the parent drug. O-Desmethylated derivatives of dimefluron prevailed among the phase I metabolites.
- MeSH
- antitumorózní látky analýza chemie metabolismus MeSH
- financování organizované MeSH
- fluoreny analýza chemie metabolismus MeSH
- hmotnostní spektrometrie metody MeSH
- krysa rodu rattus MeSH
- spektrofotometrie ultrafialová metody MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- MeSH
- antitumorózní látky analýza farmakokinetika chemie MeSH
- fluoreny analýza chemie MeSH
- játra cytologie MeSH
- karcinogeny chemie MeSH
- krysa rodu rattus MeSH
- spektrofotometrie ultrafialová MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- žluč chemie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- techniky in vitro MeSH
