Independent and joint biological activity of isomeric forms of synthetic pyrethroids

Wickham, John C.

doi:10.1002/ps.2780070311

Cited by 19 publications

(5 citation statements)

References 9 publications

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“…3 For instance, Wickham compared the activity of the stereoisomers of resmethrin in topical application assays against the housefly, Musca domestica, and found the LD 50 for the 1R-trans (13 ng/insect) and 1R-cis (40 ng/insect) was hundreds of times lower than that for the 1S-trans (1,770 ng/insect) and 1S-cis (4,000 ng/insect) enantiomers. 6 A similar pattern was also observed for prallethrin by Matsuo and Miyamoto. 5 Elliott et al synthesized individual isomers of PM, and showed that the 1R-trans and 1R-cis isomers were substantially more active than their corresponding 1S enantiomers against housefly, M. domestica, and mustard beetle, Phaedon cochliariae.…”

Section: Enantioselectivity In Aquatic Toxicitysupporting

confidence: 75%

Separation and aquatic toxicity of enantiomers of synthetic pyrethroid insecticides

2005

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Synthetic pyrethroid insecticides are chiral compounds with multiple asymmetric positions. In this study, isomers of four commonly used pyrethroids were separated at the enantiomeric level by enantioselective high-performance liquid chromatography (HPLC), and differences between enantiomers in aquatic toxicity were characterized using individual isomers. Isomers of cis-bifenthrin and permethrin were completely resolved on a Sumichiral OA-2500-I column. All eight isomers of cypermethrin and cyfluthrin were completely separated on two chained Chirex 00G-3019-DO columns. Great differences were found between enantiomers in the acute toxicity to aquatic invertebrates Ceriodaphnia dubia or Daphnia magna. In cis-bifenthrin (cis-BF) and cis-permethrin (cis-PM), the 1R-cis isomer was 15-38 times more active than the 1S-cis enantiomer, while in trans-PM, the 1R-trans isomer was substantially more toxic than the 1S-trans enantiomer. In cypermethrin or cyfluthrin, two of the eight isomers, 1R-cis-alphaS and 1R-trans-alphaS, contributed for almost all the toxicity in the racemate, while the other six enantiomers were inactive. These results suggest that significant enantioselectivity occurs for pyrethroids in aquatic toxicity, and such enantiomeric differences must be considered when evaluating ecological effects of pyrethroid insecticides.

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Section: Enantioselectivity In Aquatic Toxicitysupporting

confidence: 75%

Separation and aquatic toxicity of enantiomers of synthetic pyrethroid insecticides

2005

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“…Apart from a few exceptions most of the studies report from additive to antagonist interactions among isomers. Additive interaction or antagonism were observed in different isomer mixtures of resmethrin on housefly (Wickham 1976). Mutual antagonism between pairs of allethrin isomers was found in the same study.…”

Section: Joint Action Among Cypermethrin Stereoisomerssupporting

confidence: 50%

The synthetic pyrethroid isomers II. Biological activity

Pap

Kelemen

Tóth

et al. 1996

Journal of Environmental Science and Health, Part B

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Pure optical isomers of phenothrin, permethin and cypermethrin were synthesised and tested on a wide spectrum of insects (Blattella germanica, Leptinotarsa decemlineata, Tribolium confusum, Oncopeltus fasciatus, Musca domestica, Aedes aegypti). Our results suggest that in the structurally related series phenothrin, permethrin and cypermethrin the chemical modifications had only a small influence on intrinsic activity of the compounds at the target site. The activity of piperonylbutoxide synergised 1Rtrans phenothrin and 1Rcis permethrin (LD 50 =1.2 ng/fly in both cases) is in a similar range to the most active 1RcisS cypermethrin isomer alone or with PB (LD 50 =0.9 and 0.4 ng/fly, respectively). Some cypermethrin isomers considered previously to be totally inactive show significant activity depending on the tested insect species. The 1ReisR and 1RtransR isomers proved to be as active as the most potent isomers on mosquito. A similarly unexpected result was that in the case of mosquito all four trans isomers were significantly more active than the corresponding eis isomers. 528 PAP ET AL.The superiority of the (S)-α configuration over (R)-α was found. It does not result from a higher intrinsic activity at the target site, but rather from the enhanced metabolic resistance of (S)-α-esters to ester cleavage as confirmed by Synergist studies. The activity of the two most potent stereoisomers, 1ReisS and 1RtransS, could not be elevated by quinalphos, while the inactive 1ScisR and 1StransR isomers showed significant activity with the esterase inhibitor quinalphos administered sublethally.In contrast with the antagonism between (S)-and (R)-α-epimers of cypermethrin reported earlier a considerable synergism was observed between 1RtransS and 1StransR enantiomer pair on flour beetle and housefly in tarsal contact tests.The results with stereoisomers and their mixtures were utilised in the development of two new products, Chinmix (beta-cypermetrhin) and Transmix (theta-cypermetrhin).

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“…As with any biologically active material, the mammalian and insect toxicity of insecticides is often related to their configuration. The different isomers may additionally show selective toxicity, differing rates of biodegradation, and unique chronic effects (Sagar et al, 1972;Elliott et al, 1974;Ohkawa et al, 1977;Casida and Soderlund, 1977;Wickham, 1977;Henrick et al, 1978; for earlier references, see Wustner, 1971). It will become increasingly important for industry and regulatory agencies to monitor the configuration of some products.…”

Section: Resultsmentioning

confidence: 99%

Development of an S-bioallethrin specific antibody

Wing¹,

Hammock²,

Wustner³

1978

J. Agric. Food Chem.

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Residue analysis of the pyrethrins and allethrin as well as newer pyrethroid insecticides not containing halogens such as resmethrin and phenothrin is expensive, tedious, and/or of poor sensitivity. The structure of such pyrethroids suggests that they can be analyzed quickly, inexpensively, and at low levels by radioimmunoassay. Reaction of S-bioallethrin (IR,BRA'S) with carboxymethoxylamine hemihydrochloride led to quantitative conversion to its carbomethoxyoxime derivative. Alternatively, hydroboration-oxidation of S-bioallethrin with disiamylborane led to selective oxidation at the terminal olefin with little loss of specific rotation. Quantitative reaction with succinic anhydride gave S-bioallethrin hemisuccinate which was conjugated via its N-hydroxysuccinimide active ester to tyramine, hemocyanin, or bovine serum albumin (BSA). Rabbits immunized with allethrin-hemocyanin yielded a serum reacting with hemocyanin or allethrin-BSA but not BSA as determined by immunodiffusion. Appearance of the precipitin band to allethrin-BSA could be inhibited by S-bioallethrin, but not by higher levels of permethrin, parathion, carbaryl, DDT, or an inactive allethrin isomer (1S,BRA'R)-The potential of immunochemical methods for residue analysis is discussed.The analysis of pesticide residues is necessary for insuring environmental quality and human health. Gasliquid chromatography (GLC) with selective detectors has proven to be the most generally applicable residue analysis technique, but for some groups of compounds GLC analysis has severe limitations. S-Bioallethrin (the 1R-, 3R-, or (±)-trans-chrysanthemate of 4'S-allethrelone, compound 1, Figure 1) and the natural pyrethrins (rethrins) have limited but important uses in insect control due to their effectiveness on insects, their very low mammalian toxicity, and their rapid decomposition (Elliott et al., 1978). This low mammalian toxicity has resulted

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Independent and joint biological activity of isomeric forms of synthetic pyrethroids

Cited by 19 publications

References 9 publications

Separation and aquatic toxicity of enantiomers of synthetic pyrethroid insecticides

Separation and aquatic toxicity of enantiomers of synthetic pyrethroid insecticides

The synthetic pyrethroid isomers II. Biological activity

Development of an S-bioallethrin specific antibody

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