Metabolism of norflurazon by rats

Quistad, Gary B.; Saunders, A L; Skinner, Wayne S.; Reuter, Carol C.; Collier, Katherine D.

doi:10.1021/jf00089a045

Cited by 5 publications

(5 citation statements)

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“…Magi 1, 2, 3, 4, 5 and 6 are composed of 38, 40, 46, 43, 29, and 38 amino acid residues, respectively (Table 1A). The amino acid sequences of Magi 3 and 4 share some similarities to the sequences of the neuropeptide PlTx‐II from the venom of the American plectreurid spider Plectreurys tristis [23,24] and the δ‐atracotoxins from the Australian hexathelid spiders A. robustus [4] and H. versuta [5] (Table 1B). The amino acid sequences of Magi 1 and 2 are homologous to each other, whereas both of them displayed no significant sequence similarity to any other peptides.…”

Section: Resultsmentioning

confidence: 88%

Distinct primary structures of the major peptide toxins from the venom of the spider Macrothele gigas that bind to sites 3 and 4 in the sodium channel¹

et al. 2003

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Six peptide toxins (Magi 1^6) were isolated from the Hexathelidae spider Macrothele gigas. The amino acid sequences of Magi 1, 2, 5 and 6 have low similarities to the amino acid sequences of known spider toxins. The primary structure of Magi 3 is similar to the structure of the palmitoylated peptide named PlTx-II from the North American spider Plectreurys tristis (Plectreuridae). Moreover, the amino acid sequence of Magi 4, which was revealed by cloning of its cDNA, displays similarities to the Na + channel modi¢er N N-atracotoxin from the Australian spider Atrax robustus (Hexathelidae). Competitive binding assays using several 125 I-labelled peptide toxins clearly demonstrated the speci¢c binding a⁄nity of Magi 1^5 to site 3 of the insect sodium channel and also that of Magi 5 to site 4 of the rat sodium channel. Only Magi 6 did not compete with the scorpion toxin LqhK KIT in binding to site 3 despite high toxicity on lepidoptera larvae of 3.1 nmol/g. The K i s of other toxins were between 50 pM for Magi 4 and 1747 nM for Magi 1. In addition, only Magi 5 binds to both site 3 in insects (K i = 267 nM) and site 4 in rat brain synaptosomes (K i = 1.2 nM), whereas it showed no a⁄nities for either mammal binding site 3 or insect binding site 4. Magi 5 is the ¢rst spider toxin with binding a⁄nity to site 4 of a mammalian sodium channel. ß

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Section: Resultsmentioning

confidence: 88%

Distinct primary structures of the major peptide toxins from the venom of the spider Macrothele gigas that bind to sites 3 and 4 in the sodium channel¹

et al. 2003

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“…28> It was reported that NR was also metabolized through N-demethylation on in vivo metabolism in rats. 29 In addition, NR seemed to be metabolized to these metabolites by CYP 1 A 1 and CYP 1 A2 because of the same retention in HPLC analysis.…”

Section: Analysis Of Metabolites Of Herbicides and Othermentioning

confidence: 97%

Metabolism of Herbicides and Other Chemicals in Human Cytochrome P450 Species and in Transgenic Potato Plants Co-Expressing Human CYP1A1, CYP2B6 and CYP2C19

et al. 2001

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Metabolism of 50 herbicides and 7 other chemicals with different structures and modes of action was examined in the microsomes from the recombinant yeast strains expressing each of 11 human P450 species. Of these, 27 herbicides and 6 other chemicals were mainly metabolized by CYP1A1, CYP1A2, CYP2B6, CYP2C9, CYP2C 18, CYP2C 19, CYP2D6 and CYP3A4. The metabolites of atrazine (AT), chlortoluron (CT), fenitrothion (FT), methoxychior (MXC), pyributicarb (PC), simazine (SZ) and simetryn (ST) were identified by co-chromatography with the authentic standards as well as LC/MS and GC/MS of their derivatives. Based on these results, three major P450 species CYP1A1, CYP2B6 and CYP2C19 in different families and subfamilies were selected and then co-expressed in the transgenic potato plant T1977, which showed cross-tolerance toward the herbicides acetochlor (AC), AT, CT, methabenzthiazuron (MT), metolachlor (MC), norflurazon (NR) and PC. ' The T1977 plant showed a higher activity in the metabolism of each of [14C] CT, [14C] AT, [14C] PC and [14C] MXC than the control. In T1977, [14C] PC was almost completely metabolized to m-tent-butylphenol(BP), 0-demethylated PC (DMPC), hydroxylated BP (BPOH) and unknown metabolites. Also, [14C] MXC was rapidly metabolized in T1977 through 0-demethylation to yield mono-demethylated and di-demethylated metabolites, which were mainly deposited as glucosides in the plants. These results strongly suggested that three P450 species expressed in T1977 coordinately functioned and actively metabolized the herbicides and the insecticide. The transgenic plants expressed human P450 species metabolizing xenobiotics seem to be useful for generation of transgenic crops with low pesticide residues as well as for phytoremediation of pesticide residues.

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“…The structure of flufenpyr-ethyl is rather related to pyridazinone herbicides (photosynthesis inhibitor) since flufenpyr-ethyl has a pyridazinone ring and an ethyl phenoxyacetate moiety. The metabolism of pyridazinone herbicides, such as chloridazon (7 ) and norflurazon (8 ), was reported previously.…”

Section: Introductionmentioning

confidence: 71%

“…The pyridazinone ring was not opened in rats and mice as well as pyridazinone herbicides (7,8). It seems that the pyridazinone ring is metabolically stable in mammals.…”

mentioning

confidence: 99%

Metabolism of Flufenpyr-ethyl in Rats and Mice

Nagahori

Matsunaga

Tomigahara

et al. 2009

J. Agric. Food Chem.

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The metabolism of flufenpyr-ethyl [ethyl 2-chloro-5-[1,6-dihydro-5-methyl-6-oxo-4-(trifluoromethyl)pyridazin-1-yl]-4-fluorophenoxyacetate] was examined in rats and mice. [Phenyl-(14)C]flufenpyr-ethyl was administered to rats and mice as a single oral dose at a level of 500 mg/kg, and (14)C-excretion was examined. Total (14)C-recoveries within 7 days after administration were 93.2 to 97.5% (feces, 42.0 to 46.0%; and urine, 47.2 to 55.5%) in rats and 92.6 to 96.4% (feces, 26.7 to 32.7%; and urine, 59.9 to 69.7%) in mice. (14)C-Excretion into expired air was not detected in rats (expired air of mice was not analyzed). No marked species- or sex-related differences were observed in the rate of (14)C-elimination, but a relatively higher excretion into the urine of mice was observed compared to that in rats. (14)C-residues in tissue 7 days after administration were relatively high for liver, hair, skin, and kidney, but total (14)C-residues were low, below 0.2% of the dose. An ester cleaved metabolite (S-3153acid) was the major metabolite in feces and urine. Hydroxylation of the methyl group on the C5 of the pyridazine ring and ether cleavage were also observed. No sex-related differences were observed in (14)C-elimination, (14)C-distribution, and metabolite profiles, and metabolism of flufenpyr-ethyl in rats and mice was similar. In vitro metabolism of flufenpyr-ethyl was examined using stomach and intestinal contents and blood and liver S9 fractions (postmitochondrial supernatant fractions) in rats. S-3153acid was detected as a major metabolite in the presence of intestinal contents and blood and liver S9 fractions, and a small amount was also formed in the presence of stomach contents, indicating that the parent compound is rapidly metabolized by intestinal contents and blood and liver S9 fractions through ester cleavage.

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Metabolism of norflurazon by rats

Cited by 5 publications

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Distinct primary structures of the major peptide toxins from the venom of the spider Macrothele gigas that bind to sites 3 and 4 in the sodium channel¹

Distinct primary structures of the major peptide toxins from the venom of the spider Macrothele gigas that bind to sites 3 and 4 in the sodium channel¹

Metabolism of Herbicides and Other Chemicals in Human Cytochrome P450 Species and in Transgenic Potato Plants Co-Expressing Human CYP1A1, CYP2B6 and CYP2C19

Metabolism of Flufenpyr-ethyl in Rats and Mice

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Metabolism of norflurazon by rats

Cited by 5 publications

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Distinct primary structures of the major peptide toxins from the venom of the spider Macrothele gigas that bind to sites 3 and 4 in the sodium channel1

Distinct primary structures of the major peptide toxins from the venom of the spider Macrothele gigas that bind to sites 3 and 4 in the sodium channel1

Metabolism of Herbicides and Other Chemicals in Human Cytochrome P450 Species and in Transgenic Potato Plants Co-Expressing Human CYP1A1, CYP2B6 and CYP2C19

Metabolism of Flufenpyr-ethyl in Rats and Mice

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Product

Resources

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Distinct primary structures of the major peptide toxins from the venom of the spider Macrothele gigas that bind to sites 3 and 4 in the sodium channel¹

Distinct primary structures of the major peptide toxins from the venom of the spider Macrothele gigas that bind to sites 3 and 4 in the sodium channel¹