Insecticidal activity of the enantiomers of fipronil

Teicher, Harald Bernhard; Kofoed-Hansen, Britt; Jacobsen, Niels

doi:10.1002/ps.819

Cited by 35 publications

(30 citation statements)

References 5 publications

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“…Fipronil enantiomers were separated using a Jasco LC-2000 series HPLC system (Jasco, Japan) according to an established method 21 . The resolved fractions were manually collected at the HPLC outlet, evaporated until dry, and dissolved in ethanol.…”

Section: Methodsmentioning

confidence: 99%

Fipronil-induced enantioselective developmental toxicity to zebrafish embryo-larvae involves changes in DNA methylation

Qian

Wang

et al. 2017

Sci Rep

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Enantioselectivity in the aquatic toxicity of chiral pesticides has been widely investigated, while the molecular mechanisms remain unclear. Thus far, few studies has focused on genomic expression related to selective toxicity in chiral pesticide, nor on epigenetic changes, such as DNA methylation. Here, we used fipronil, a broad-spectrum insecticide, as a model chemical to probe its enantioselective toxicity in embryo development. Our results showed that S-(+)-fipronil caused severer developmental toxicity in embryos. The MeDIP-Seq analysis demonstrated that S-(+)-fipronil dysregulated a higher level of genomic DNA methylation than R-(−)-fipronil. Gene Ontology analysis revealed that S-(+)-fipronil caused more differentially methylated genes that are involved in developmental processes. Compared with R-(−)-fipronil, S-(+)-fipronil significantly disrupted 7 signaling pathways (i.e., mitogen-activated protein kinases, tight junctions, focal adhesion, transforming growth factor-β, vascular smooth muscle contraction, and the hedgehog and Wnt signaling pathways) by hyper-methylation of developmentally related genes, which further induced the downregulation of those genes. Together, these data suggest that differences in DNA methylation may partly explain the enantioselectivity of fipronil to zebrafish embryos. The application of epigenetics to investigate the enantioselective toxicity mechanism of chiral chemicals would provide a further understanding of their stereoselectivity biological effects.

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Section: Methodsmentioning

confidence: 99%

Fipronil-induced enantioselective developmental toxicity to zebrafish embryo-larvae involves changes in DNA methylation

Qian

Wang

et al. 2017

Sci Rep

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“…26,27 In addition, the α,β configuration of the glucosyl group also exists. Their configurations were confirmed on the basis of a chemical shift, coupling constants, and band shape of H-1.…”

Section: ■ Results and Discussionmentioning

confidence: 97%

Glucose Positions Affect the Phloem Mobility of Glucose–Fipronil Conjugates

Lei

Wang

Mao

et al. 2014

J. Agric. Food Chem.

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In our previous work, a glucose-fipronil (GTF) conjugate at the C-1 position was synthesized via click chemistry and a glucose moiety converted a non-phloem-mobile insecticide fipronil into a moderately phloem-mobile insecticide. In the present paper, fipronil was introduced into the C-2, C-3, C-4, and C-6 positions of glucose via click chemistry to obtain four new conjugates and to evaluate the effects of the different glucose isomers on phloem mobility. The phloem mobility of the four new synthetic conjugates and GTF was tested using the Ricinus seedling system. The results confirmed that conjugation of glucose at different positions has a significant influence on the phloem mobility of GTF conjugates.

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“…There have been four studies, including the present study, that examined toxicities of fipronil enantiomers to 11 species [21][22][23]. In these 11 species, only two species (Procambarus clarkii and Ceriodaphnia dubia) demonstrated enantioselectivity in toxicities [22,23].…”

Section: Toxicitiesmentioning

confidence: 96%

“…There are a number of investigations on enantiomer-specific toxicity of fipronil in the literature. Teicher et al [21] observed no significant difference in toxicity of fipronil and its enantiomers to three agricultural and household pests (cotton stainer, Dysdercus cingulatus; grain weevil, Sitophilus granarius; house fly, Musca domestica L.). In contrast, Konwick et al [22] demonstrated the S(þ)-enantiomer was significantly more toxic to Ceriodaphnia dubia than either the R(À)-enantiomer or racemate.…”

Section: Introductionmentioning

confidence: 98%

Toxicities of fipronil enantiomers to the honeybee Apis mellifera L. and enantiomeric compositions of fipronil in honey plant flowers

Bao

Yang

et al. 2009

Enviro Toxic and Chemistry

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Fipronil is a chiral phenylpyrazole insecticide that is effective for control of a wide range of agricultural and domestic pests at low application rates. Wide application of fipronil also causes poisoning of some nontarget insects, such as honeybees. In the present study, toxicities of fipronil enantiomers and racemate to the honeybee Apis mellifera L. were determined to examine whether using formulations of single or enriched fipronil enantiomer is a possible option to reduce risks to bees. Contact toxicity tests yielded median lethal doses (LD50) of 3.45, 3.38, and 3.86 ng/bee for the R(-)-enantiomer, S(+)-enantiomer, and racemate, respectively. Analysis of variance indicates that the LD50 values are not statistically different (p = 0.41). Oral toxicities of the R-enantiomer, S-enantiomer, and racemate (nominal median lethal concentration = 0.037, 0.045, 0.053 mg/L, respectively) were also demonstrated to be not statistically different (p = 0.20). In addition, enantiomeric fractions of fipronil in the flowers of three honey plants (Brassica campestris, Cucumis sativus, and Chrysanthemum indicum L.) were examined after treatment with fipronil. It was found that degradation of fipronil in all three plants is not enantioselective. These results indicate that it is unlikely that use of formulations with single or enriched fipronil enantiomer would reduce the risk that fipronil poses to honeybees. Improved fipronil application practices (based on safest timing and bloom conditions) and reduction of overall fipronil usage seem to be more realistic options.

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Insecticidal activity of the enantiomers of fipronil

Cited by 35 publications

References 5 publications

Fipronil-induced enantioselective developmental toxicity to zebrafish embryo-larvae involves changes in DNA methylation

Fipronil-induced enantioselective developmental toxicity to zebrafish embryo-larvae involves changes in DNA methylation

Glucose Positions Affect the Phloem Mobility of Glucose–Fipronil Conjugates

Toxicities of fipronil enantiomers to the honeybee Apis mellifera L. and enantiomeric compositions of fipronil in honey plant flowers

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