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141.
Metabolism of acetaminophen (paracetamol) in plants—two independent pathways result in the formation of a glutathione and a glucose conjugate 总被引:1,自引:0,他引:1
Christian Huber Bernadett Bartha Rudolf Harpaintner Peter Schröder 《Environmental science and pollution research international》2009,16(2):206-213
Background, aim, and scope Pharmaceuticals and their metabolites are detected in the aquatic environment and our drinking water supplies. The need for
high quality drinking water is one of the most challenging problems of our times, but still only little knowledge exists on
the impact of these compounds on ecosystems, animals, and man. Biological waste water treatment in constructed wetlands is
an effective and low-cost alternative, especially for the treatment of non-industrial, municipal waste water. In this situation,
plants get in contact with pharmaceutical compounds and have to tackle their detoxification. The mechanisms for the detoxification
of xenobiotics in plants are closely related to the mammalian system. An activation reaction (phase I) is followed by a conjugation
(phase II) with hydrophilic molecules like glutathione or glucose. Phase III reactions can be summarized as storage, degradation,
and transport of the xenobiotic conjugate. Until now, there is no information available on the fate of pharmaceuticals in
plants. In this study, we want to investigate the fate and metabolism of N-acetyl-4-aminophenol (paracetamol) in plant tissues using the cell culture of Armoracia rusticana L. as a model system.
Materials and methods A hairy root culture of A. rusticana was treated with acetaminophen in a liquid culture. The formation and identification of metabolites over time were analyzed
using HPLC-DAD and LC–MSn techniques.
Results With LC–MS technique, we were able to detect paracetamol and identify three of its metabolites in root cells of A. rusticana. Six hours after incubation with 1 mM of acetaminophen, the distribution of acetaminophen and related metabolites in the
cells resulted in 18% paracetamol, 64% paracetamol–glucoside, 17% paracetamol glutathione, and 1% of the corresponding cysteine
conjugate.
Discussion The formation of two independently formed metabolites in plant root cells again revealed strong similarities between plant
and mammalian detoxification systems. The detoxification mechanism of glucuronization in mammals is mirrored by glucosidation
of xenobiotics in plants. Furthermore, in both systems, a glutathione conjugate is formed. Due to the existence of P450 enzymes
in plants, the formation of the highly reactive NAPQI intermediate is possible.
Conclusions In this study, we introduce the hairy root cell culture of A. rusticana L. as a suitable model system to study the fate of acetaminophen in plant tissues. Our first results point to the direction
of plants being able to take up and detoxify the model substrate paracetamol. These first findings underline the great potential
of using plants for waste water treatments in constructed wetlands.
Recommendations and perspectives This very first study on the detoxification of a widely used antipyretic agent in plant tissues again shows the flexibility
of plant detoxification systems and their potential in waste water treatment facilities. This study covers only the very first
steps of acetaminophen detoxification in plants; still, there is no data on long-term exposure as well as the possible impact
of pharmaceuticals on the plant health and stress defense. Long-term experiments need to be performed to follow the fate of
acetaminophen in root and leaf cells in a whole plant system, and to evaluate possible usage of plants for the remediation
of acetaminophen from waste water. 相似文献
142.
What are ecological guilds? Dilemma of guild concepts 总被引:1,自引:0,他引:1
143.
While the existence of black carbon as part of dissolved organic matter (DOM) has been confirmed, quantitative determinations of dissolved black carbon (DBC) in freshwater ecosystem and information on factors controlling its concentration are scarce. In this study, stream surface water samples from a series of watersheds subject to different burn frequencies in Konza Prairie (Kansas, USA) were collected in order to determine if recent fire history has a noticeable effect on DBC concentration. The DBC levels detected ranged from 0.04 to 0.11 mg L?1, accounting for ca. 3.32 ± 0.51% of dissolved organic carbon (DOC). No correlation was found between DBC concentration and neither fire frequency nor time since last burn. We suggest that limited DBC flux is related to high burning efficiency, possibly greater export during periods of high discharge and/or the continuous export of DBC over long time scales. A linear correlation between DOC and DBC concentrations was observed, suggesting the export mechanisms determining DOC and DBC concentrations are likely coupled. The potential influence of fire history was less than the influence of other factors controlling the DOC and DBC dynamics in this ecosystem. Assuming similar conditions and processes apply in grasslands elsewhere, extrapolation to a global scale would suggest a global grasslands flux of DBC on the order of 0.14 Mt carbon year?1. 相似文献
144.
Rudolf Engst Rainer M. Macholz Manfred Kujawa 《Journal of environmental science and health. Part. B》2013,48(4):425-427
Abstract Mexacarbate (4‐dimethylamino‐3,5‐xylyl N‐methylcarbamate) insecticide has potential for use in spruce budworm (Choristoneura fumiferana Clem.) control operations in Canada. Its persistence and fate in balsam fir (Abies balsamea (L.) Mill.), litter and soil samples were studied by spraying aerially oil‐based and water‐based formulations, each at 70 g A.I./ha over a coniferous forest near Bathurst, New Brunswick. The oil‐based formulation gave the maximum concentration of the chemical in the substrates studied. In fir needles, the highest concentrations observed were 0.51 ppm and 0.19 ppm (fresh weight) for the oil‐based and emulsion formulations respectively, 1 h after application. The residue levels decreased very rapidly with a half‐life of approximately 5 h. Three and eight days after the spray application of the emulsion and oil formulations respectively, the concentrations of mexacarbate in foliage decreased to trace levels ( 0.008 ppm). Only very low levels of residue were detected in litter and soil. The peak concentrations for the two formulations ranged from 0.02 to 0.11 ppm (fresh weight) in litter and from 0.01 to 0.06 ppm (fresh weight) in soil. The residue levels in both litter and soil decreased to below the detection limit (0.005 ppm) within 1 d. The ground deposit levels found on glass plates and the droplet density and size spectra measured on Kromekote® cards reflected the variations in concentrations found in fir needles, litter and soil samples and correlated with the observed maximum concentrations in them. Under the stipulated use pattern, mexacarbate concentrations found in the terrestrial components studied were low and are not likely to have any undue adverse effects on non‐target species. 相似文献
145.
146.
The use of conventional plastic microplates for a miniaturised luminescent bacteria test may result in an underestimation of the toxicity for poorly water soluble highly adsorbing toxicants such as PAHs. In this study, the suitability of microplates for testing elutriates of PAH-contaminated soils was investigated. The LUMIStox test was performed as the standard test in the miniaturised format using contaminated soil elutriates and aqueous solutions of four selected PAHs (viz. naphthalene (NAP), acenaphthene (ACE), fluorene (FLU), and phenanthrene (PHE)). For the aqueous PAH-solutions, we observed reduced light inhibition values for the miniaturised bioassay when using black microplates made of polypropylene (PP) and polystyrene (PS) compared to the standard LUMIStox test. This phenomenon was most likely due to adsorption of toxicants to the microplate surfaces with PAHs of lower water solubility being significantly more affected; however, after minimizing the exposure of samples to plastic surfaces, polystyrene microplates revealed equivalent performance (>80% 'relative' light inhibition) to the standard glass cuvette test system. For soil elutriates, black microplates again exhibited slightly lower light inhibition values while white plates made of PS and Barex resulted in a pronounced overestimation of toxicity for a coloured soil elutriate. In general, microplates were applicable for testing elutriates of PAH-contaminated soils. In cases where samples are coloured or turbid, the application of black microplates is recommended. 相似文献
147.
Wu RS Lau TC Fung WK Ko PH Leung KM 《Environmental pollution (Barking, Essex : 1987)》2007,145(1):104-110
A new chemical sampling device, artificial mussel (AM), has been developed for monitoring metals in marine environments. This device consists of a polymer ligand suspended in artificial seawater within a Perspex tubing, and enclosed with semi-permeable gel at both ends. Laboratory and field experiments were carried out to examine the uptake of five metals (Cd, Cr, Cu, Pb and Zn) by the AM. Uptake of metals by AM was proportional to the exposure metal concentrations, and the AM was able to accumulate the ASV labile fractions of metals. Uptake and release of the metals of AM are similar to those of the mussel Perna viridis, but less affected by salinity and temperature. Field studies demonstrated that the AM can not only provide a time-integrated estimate of metals concentrations, but also allows comparisons of metal levels in different environments and geographical areas beyond the natural distribution limits of biomonitors. 相似文献
148.
Bioaccumulation of polybrominated diphenyl ethers in harbor seals from the northwest Atlantic 总被引:1,自引:0,他引:1
Polybrominated diphenyl ethers (PBDEs) were analyzed in blubber of harbor seals (Phoca vitulina concolor) collected between 1991 and 2005 along the northwest Atlantic. ∑PBDE concentrations (mono- to hexa-BDEs) detected in blubber samples (n = 42) ranged from 80 to 25 720 ng g−1 lw, (overall mean 2403 ± 5406 ng g−1 lw). By age, mean ∑PBDE concentrations were: 3645 ± 7388, 2945 ± 5995, 1385 ± 1265, and 326 ± 193 ng g−1 lw in pups, yearlings, adult males, and adult females, respectively. Unlike the trend for PCBs, no decreasing gradient from urban to rural/remote areas was observed for PBDEs in these samples, likely reflecting inputs from local sources. No significant temporal trend was observed for PBDEs in harbor seals between 1991 and 2005, although congener profiles shifted over time. Tetra-BDE-47 was the dominant congener, followed by BDEs-99, -100, -153, -154, and -155 in varying order, suggesting exposure to the penta-BDE product. In adult males, the hexa-BDEs contributed more to the total (22%) than BDEs-99 and -100 (14%), and concentrations of BDE-155 were elevated compared with -154. Higher BDEs were detected in a subset of seals (n = 12) including hepta-BDE-183, the marker for the octa-BDE mixture, and octa-BDE-197, along with several unidentified hepta- and octa- congeners. BDE-209 was detected in seal blubber at concentrations ranging from 1.1 to 8 ng g−1 lw, indicating that deca-BDE is bioavailable in this marine food web. This is the first study to document the accumulation of BDE-209 at measurable levels in wild harbor seals. While the PBDE patterns in blubber indicate exposure to all three BDE commercial mixtures, the data also suggest that BDE-209 debromination by seal prey fish may contribute to the loading of lower brominated congeners (hexa- to octa-BDEs) in these seals. 相似文献
149.
Drei neue Nickelenzyme aus anaeroben Bakterien 总被引:2,自引:0,他引:2
Rudolf K. Thauer Astrid Brandis-Heep Gabriele Diekert Hans -Harald Gilles Ernst Günther Graf Rolf Jaenchen Peter Schönheit 《Die Naturwissenschaften》1983,70(2):60-64
Until recently nickel was not considered to be an element of biological importance. Nutritional studies have shown, however, that many eucaryotic and procaryotic organisms are dependent on the transition metal for growth. Four enzymes are presently known to contain nickel: urease from plants and from bacteria; methyl CoM reductase from methanogenic bacteria; all “uptake” hydrogenases investigated so far; and carbon monoxide dehydrogenase from anaerobic bacteria. The prosthetic group of the methyl CoM reductase has been identified as a nickel tetrapyrrole, the structure of which has been elucidated. 相似文献
150.
Bret A. Schichtel Rudolf B. Husar 《Journal of the Air & Waste Management Association (1995)》2013,63(3):301-314
The Product Guide series which appears in the Journal of the Air Pollution Control Association and the APCA Directory and Resource Book is a computer-based program. A questionnaire form provided entry into the program for responding manufacturers of emission control equipment and air pollution instrumentation. If any manufacturers or product categories have been overlooked, the omission is regretted and should be brought to the attention of the editor, JAPCA. 相似文献