bromfenacoum and flocoumafen

Anticoagulant rodenticides (ARs) are used worldwide for rodent population control to protect human health and biodiversity, and to prevent agricultural and economic losses. Rodents may develop a metabolic resistance to ARs. In order to help understand such metabolic resistance, mass spectrometry was used to position the hydroxylated group of hydroxyl metabolites of second-generation ARs (SGARs).. Most AR pesticides are derived from the 4-hydroxycoumarin/thiocoumarin family. We used low-resolution and high-resolution mass spectrometry to understand the fragmentation pathways of the ARs and their respective metabolites, and to better define the structure of their tandem mass spectrometry product ions.. Seven specific product ions were evidenced for five ARs, with their respective chemical structures. Those ions were obtained as well from the mass spectra of the hydroxyl metabolites of four SGARs, difenacoum (DFM), brodifacoum (BFM), difethialone (DFTL) and flocoumafen (FLO), with different positions of the hydroxyl group.. The differences in chemical structure between DFM on the one hand and BFM, FLO and DFTL on the other could explain the differences in bioavailability between these two groups of molecules. The defined product ions will be used to investigate the part played by the metabolic issue in the field resistance of SGARs.

Topics: 4-Hydroxycoumarins; Animals; Anticoagulants; Biological Availability; Hydroxylation; Liver; Male; Rats, Sprague-Dawley; Rodenticides; Tandem Mass Spectrometry

Superwarfarins, second-generation long-acting anticoagulant rodenticides, are 4-hydroxycoumarin analogues of warfarin that contain a large hydrophobic side chain. These compounds contain two chiral centers and are synthesized for commercial use as two pairs of diastereomer.. To support studies of superwarfarin pharmacokinetics and other efforts to improve clinical care for poisoning victims, a quantitative assay was developed for the measurement of diastereomer of bromadiolone, difenacoum, flocoumafen, brodifacoum, and difethialone in human plasma.. Based on ultrahigh-pressure liquid chromatography-tandem mass-spectrometry (UHPLC-MS/MS), this method was validated according to U.S. Food and Drug Administration (FDA) guidelines. Sample preparation involved simple protein precipitation followed by reversed phase UHPLC, which resolved all five pairs of cis/trans diastereomer in less than 10 min. Superwarfarins were measured using negative ion electrospray followed by selected-reaction monitoring on a triple quadrupole mass spectrometer.. Calibration curves covered 3-4 orders of magnitude with linear regression coefficients of >0.999. The lower limits of quantitation were from 0.013 to 2.41 ng/mL, and intra-day and inter-day accuracy and precision coefficients of variation were <12%.. A 10-min UHPLC-MS/MS assay was developed and validated for the separation and quantitative analysis of the pairs of diastereomer of five superwarfarins in human plasma.. This method was used to identify and measure superwarfarins and their cis/trans diastereomers in plasma obtained from patients treated for coagulopathy following consumption of contaminated synthetic cannabinoid products.

Topics: 4-Hydroxycoumarins; Anticoagulants; Chromatography, High Pressure Liquid; Humans; Reproducibility of Results; Rodenticides; Tandem Mass Spectrometry

Anticoagulant rodenticides (ARs) have been used for decades for rodent control worldwide. Research on the exposure of the environment and accumulation of these active substances in biota has been focused on terrestrial food webs, but few data are available on the impact of ARs on aquatic systems and water organisms. To fill this gap, we analyzed liver samples of bream (Abramis brama) and co-located suspended particulate matter (SPM) from the German Environmental Specimen Bank (ESB). An appropriate method was developed for the determination of eight different ARs, including first- and second-generation ARs, in fish liver and SPM. Applying this method to bream liver samples from 17 and 18 sampling locations of the years 2011 and 2015, respectively, five ARs were found at levels above limits of quantifications (LOQs, 0.2 to 2 μg kg

Topics: 4-Hydroxycoumarins; Animals; Anticoagulants; Aquatic Organisms; Cyprinidae; Environmental Monitoring; Food Chain; Fresh Water; Germany; Liver; Particulate Matter; Rodenticides; Seafood; Water Pollutants, Chemical

Anticoagulant rodenticides (ARs) are known to cause extensive secondary exposure in top predators in Europe and North America, but there remains a paucity of data in Asia. In this study, we collected 221 liver samples from 21 raptor species in Taiwan between 2010 and 2018. Most birds were recovered from rescue organizations, but some free-ranging individuals were obtained from bird-strike prevention measures at airports. ARs were detected in 10 species and more than half of the total samples. Common rodent-eating Black-winged Kites (Elanus caeruleus) had the highest prevalence (89.2%) and highest average sum concentration (0.211 ± 0.219 mg/kg), which was similar between free-ranging birds at airports and injured birds from rescue organizations. Scavenging Black Kites (Milvus migrans) and snake-eating Crested Serpent-eagles (Spilornis cheela) had the second highest prevalence or sum concentration, respectively. Seven different AR compounds were detected, of which brodifacoum was the most common and had the highest average concentration, followed by flocoumafen and bromadiolone. The frequency of occurrence in the three most numerous species (Black-winged Kite, Crested Goshawk [Accipiter trivirgatus], and Collared Scops-owl [Otus lettia]) was significantly higher in autumn than summer, which is consistent with the timing of the Taiwanese government's supply of free ARs to farmers. Regional differences in the detection of individual compounds also tended to reflect differences in human population density and use patterns (in agriculture or urban-dominated environments). Clinical poisoning was confirmed in Black Kites with sum concentrations as low as 0.026 mg/kg; however, further study of interspecific differences in AR sensitivity and potential population effects are needed. In addition, continued monitoring remains important given the Taiwanese government has modified their farmland rodent control policy to gradually reduce free AR supplies since 2015.

Topics: 4-Hydroxycoumarins; Animals; Anticoagulants; Environmental Monitoring; Environmental Pollutants; Raptors; Rodent Control; Rodenticides; Taiwan

The occurrence of 10 commonly used anticoagulant rodenticides in centrifuged sludge of 27 wastewater treatment plants was evaluated using solid-liquid extraction (SLE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Activated carbon, alumina, and Florisil cartridges with methanol/dichloromethane as eluting solvents were tested in combination with primary-secondary amine (PSA) to optimize an efficient sample cleanup. PSA in combination with Florisil was the best methodology to extract anticoagulant rodenticides in sludge providing recoveries between 42 ± 0.5 and 100 ± 2 %. Warfarin, bromadiolone, ferulenol, and coumachlor were the most ubiquitous compounds in sludge at concentrations up to 84.2 ng g(-1) for the latter. Coumatetralyl, dicoumarol, and brodifacoum were detected sporadically at levels between 6.1 and 17.4 ng g(-1). On the contrary, acenocoumarol, difenacoum, and flocoumafen were not detected in any sample. Finally, we estimated the amount of anticoagulant rodenticides discharged via sludge in order to determine the potential impact to agricultural soil according to different sludge usage practices in the region investigated. This study demonstrates that anticoagulant rodenticides are accumulated in sludge during activated sludge treatment and that the application of sludge as fertilizers may pose a future environmental risk, if not controlled.

Topics: 4-Hydroxycoumarins; Anticoagulants; Chromatography, High Pressure Liquid; Coumarins; Rodenticides; Sewage; Tandem Mass Spectrometry; Warfarin; Wastewater

Coumarins are natural substances found in a variety of plants. It is well known that plant-derived natural products are extensively used as biologically active compounds. Among them, coumarins were the first preservatives used by man, originally in their natural state within plant tissues and then as natural materials obtained by water distillation. During our search for new types of coumarin derivatives possessing a larvicidal activity, we investigated the synthesis of 4-hydroxycoumarin derivatives.. The coumarin derivatives were synthesized and the structure determination and larvicidal effects were studied.. The structure analyses were conducted by nuclear magnetic resonance (NMR), and mass (MS) spectroscopy revealed that the coumarin derivatives were obtained in good yields, and the eight coumarin derivatives were 3-{1,2,3,4-tetrahydro-3-[4-(4-trifluoromethylbenzyloxy)phenyl}-1-naphthalen-1-on (1), 3-{1,2,3,4-tetrahydro-3-[4-(4-trifluoro methylbenzyloxy)phenyl}-1-naphthalen-1-ol (2), brodifacoum (3), difethialone (4), bromadiolone (5), 4-hydroxy-3-(1,2,3,4-tetrahydronaphthalen-1-yl)-2H-chromen-2-one (coumatetralyl) (6), cis-flocoumafen (7) and trans-flocoumafen (8).. The compounds were tested against the F(21) laboratory strain of Aedes aegypti L. Brodifacoum and cis-flocoumafen mediated strong activity with an LC(50) values of 8.23 and 9.34 ppm, respectively.. The above indicates that brodifacoum may play a more important role in the toxicity of 4-hydroxycoumarin derivatives.

Topics: 4-Hydroxycoumarins; Aedes; Animals; Insecticides; Larva; Lethal Dose 50; Magnetic Resonance Spectroscopy; Mass Spectrometry

Ireland has a restricted small mammal prey guild but still includes species most likely to consume anticoagulant rodenticide (AR) baits. This may enhance secondary exposure of predators to ARs. We compared liver AR residues in foxes (Vulpes vulpes) in Northern Ireland (NI) with those in foxes from Great Britain which has a more diverse prey guild but similar agricultural use of ARs. Liver ARs were detected in 84% of NI foxes, more than in a comparable sample of foxes from Scotland and similar to that of suspected AR poisoned animals from England and Wales. High exposure in NI foxes is probably due to greater predation of commensal rodents and non-target species most likely to take AR baits, and may also partly reflect greater exposure to highly persistent brodifacoum and flocoumafen. High exposure is likely to enhance risk and Ireland may be a sentinel for potential effects on predator populations.

Topics: 4-Hydroxycoumarins; Animals; Anticoagulants; Biodiversity; Environmental Exposure; Female; Food Chain; Foxes; Ireland; Liver; Male; Mammals; Risk Assessment; Rodenticides

A simple, accurate and sensitive method has been developed for the simultaneous determination of warfarin, coumatetralyl, bromadiolone, flocoumafen and brodifacoum in whole blood by high performance liquid chromatography (HPLC) with fluorescence detection. The five 4-hydroxycoumarin rodenticides in whole blood were extracted by ethyl acetate, separated on XDB C,, column( 150 mm x 2. 1 mm, 5 [microm) by using the mobile phase consisting of methanol-0. 2% acetic acid aqueous solution (88: 12, v/v) at a flow rate of 0. 5 mL/min and detected with a variational time program for fluorescence wavelength. Each analyte was qualitatively determined with its fluorescence excitation spectrum, fluorescence emission spectrum and retention time being compared with those of the reference standard, and quantified with external calibration method. The linear range was 0. 01 - 10. 00 mg/L and the limit of quantification was 0. 01 mg/L except warfarin of which the corresponding results were 0. 05 - 10. 00 mg/L and 0. 05 mg/L. The recoveries were between 81% and 98% and the relative standard deviations (RSDs) were between 3. 8% and 8. 5%. This method can be used in the diagnosis of the clinical poisoned patients.

Topics: 4-Hydroxycoumarins; Chromatography, High Pressure Liquid; Humans; Reproducibility of Results; Rodenticides; Warfarin

A rapid, sensitive and selective method for the simultaneous determination of bromadiolone, flocoumafen and brodifacoum in whole blood using warfarin as internal standard (IS) by high-performance liquid chromatography coupled with electrospray ionization mass spectrometry (HPLC/ESI-MS) has been developed and validated. The target compounds were extracted from the whole blood with ethyl acetate and separated on an XDB C18 column (150 mm x 2.1 mm i.d. x 5 microm) by using a mobile phase consisting of 0.2% acetic acid/methanol (12/88, v/v) at a constant flow rate of 0.50 mL/min. The analytes were detected using negative ESI-MS in the selected ion monitoring (SIM) mode. The molecular ions [M-H]- of m/z 527, 541,523 and 307 were selected for the quantification for bromadiolone, flocoumafen, brodifacoum and the IS, respectively. The calibration curves were linear (r2 > 0.995) in the concentration range of 0.50-100.00 ng/mL. The method showed a satisfactory sensitivity (0.05-0.5 ng/mL using 200 microL blood), precision (RSD < 11.9%), accuracy (recovery: 82.0-96.1%) and selectivity. This method was successfully applied to the determination of the analytes for the diagnoses of poisoned human beings and animals.

Topics: 4-Hydroxycoumarins; Anticoagulants; Chromatography, High Pressure Liquid; Humans; Reproducibility of Results; Rodenticides; Spectrometry, Mass, Electrospray Ionization

Polecats (Mustela putorius) in Britain are currently expanding their range eastwards from Wales to reoccupy central and eastern areas of England. Second-generation anticoagulant rodenticides (SGARs), to which polecats are exposed by eating contaminated prey, are used more extensively in these central and eastern regions, leading to fears of increased exposure, and possible resultant mortality. We measured bromadiolone, difenacoum, flocoumafen and brodifacoum concentrations in the livers of 50 polecats from areas that included newly recolonised habitats and found that at least one SGAR was detected in the livers of 13 out of 37 (35.1%) male and 5 out of 13 (38.5%) female polecats. Difenacoum and bromadiolone were detected most frequently. We then combined these data with measurements on another 50 individuals from earlier studies to create a dataset for 100 polecats collected throughout the 1990s from across the whole of their current range. Using this dataset, we determined if there was any evidence that contamination in polecats had increased during the 1990s and whether animals from England were more contaminated than those from Wales, as might be expected given regional differences in the patterns of SGAR use. Overall, 31 of the 100 polecats analysed to date contained SGAR residues. The incidence was a little higher (40%) in animals that died between January and June and this probably better reflects the overall proportion of animals that are sub-lethally exposed. There was no statistically significant change during the 1990s in the proportion of polecats exposed to SGARs nor any evidence that greater use of SGARs in England resulted in more contamination of polecats. Contrary to expectation, the proportion of animals that contained difenacoum was marginally higher in Wales than elsewhere.

Topics: 4-Hydroxycoumarins; Animals; Anticoagulants; Female; Ferrets; Liver; Male; Pesticide Residues; Rodenticides; Time Factors; United Kingdom