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The in vitro metabolism of the chiral isomers of fonofos and fonofos oxon in the presence of mouse liver mixed-function oxidase and serum esterase was investigated. The metabolism of 35S-labeled phenyl-(S)P-fonofos mediated by mixed-function oxidase took place stereoselectively, resulting predominantly in (R)P-fonofos oxon. Similarly, (R)P-fonofos was converted to (S)P-oxon. In each case, however, a significant amount of racemization occurred. Other products were diphenyl disulfide and diphenyl disulfide oxide. In addition to stereospecificity, the oxidative metabolism of (R)P-fonofos proceeded at a rate faster than that of (S)P-fonofos. Stereoselective rate differences also were observed in mouse or rat serum-catalzyed degradation of the fonofos oxon enantiomers, the (S)P isomer being degraded about twofold faster than its enantiomer. The differences in toxicities of the isomers of fonofos and fonofos oxon were consistent with the in vitro metabolism data. 相似文献
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The selective toxicity of new N-phosphorothioyl-carbamate esters 总被引：4，自引：0，他引：4
M A Fahmy T R Fukuto R O Myers R B March 《Journal of agricultural and food chemistry》1970,18(5):793-796
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Takaaki Nishioka Noriharu Umetsu T.Roy Fukuto 《Pesticide biochemistry and physiology》1981,16(2):141-148
The fate of the di-n-butylaminosulfenyl moiety in 2,3-dihydro-2,2-dimethyl-7-benzofuranyl (di-n-butylaminosulfenyl)(methyl)carbamate (DBSC or Marshal) was studied in the cotton plant at 1, 3, 6, and 10 days following foliage treatment with [di-n-butylamino-14C]DBSC. Dibutylamine and two major radioactive metabolites were obtained following extraction of the plant tissue with a methanol-buffer containing N-ethylmaleimide (NEM), a sulfhydryl scavenger which was added to prevent the cleavage of the NS bond during the workup procedure. The most adundant radioactive material recovered from plants was identified as a product arising from the reaction between NEM and dibutylamine. Extraction of plant tissue with straight methanol-buffer solution or with methol-buffer containing other sulfhydryl scavengers resulted in 57–86% of the applied radioactivity being recovered as dibutylamine in the organosoluble fraction. When [14C]dibutylamine was applied to cotton leaves, most of the radioactivity, i.e., 96% of the total recovered radioactivity, was found in the organosoluble fraction as dibutylamine. Dibutylamine is the major metabolite of [di-n-butylamino-14C]DBSC in the cotton plant. 相似文献
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Mangel S. Malik Richard S. Vetter Thomas C. Baker T. Roy Fukuto 《Pest management science》1991,32(1):35-46
A series of dialkyl phosphorofluoridates and alkyl methylphosphono-fluoridates in which one or two of the alkyl moieties were long-chain alkyl groups were synthesized and examined for their ability to disrupt moth sex pheromone-mediated behavior of the oriental fruit moth, Grapholita molesta. Disruption of pheromone-mediated behavior was found only for those compounds containing a (Z)-8-dodecenyl moiety, i.e. the alkyl substituent of the principal pheromone component ((Z)-8-dodecenyl acetate) of the oriental fruit moth. Di-((Z)-8-dodecenyl) phosphorofluoridate was nearly as disruptive as (Z)-8-dodecenyl acetate. 相似文献
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The synthesis of the four optical isomers of known absolute configuration of O-2-butyl S-2-(dimethylammonium)ethyl ethylphosphonothioate hydrogen oxalate is described. Values for the affinity constant (Ka), phosphonylation constant (kp), and bimolecular inhibition rate constant (ki) for the inhibition of bovine erythrocyte acetylcholinesterase, housefly-head acetylcholinesterase, and horse serum cholinesterase by the chiral isomers and the racemic mixture are reported. Using a relatively simple spectrophotometric technique, inhibition times as low as 0.5 sec were used. The phosphorus isomers of Sp configuration were more potent inhibitors than their Rp enantiomers by 1630-fold against the bovine enzyme, 9120-fold against the fly-head enzyme, and 40-fold against the horse serum enzyme. The differences in anticholinesterase activity were attributable to differences in the affinity constant, Ka, and the phosphonylation constant, kp. Small but consistent inhibition rate differences were attributable to asymmetry at carbon. Against horse serum cholinesterase, the SC isomers indicated the presence of three kinetic forms in this enzyme preparation. 相似文献
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Noriharu Umetsu Mohamed A.H. Fahmy T.Roy Fukuto 《Pesticide biochemistry and physiology》1979,10(1):104-119
The absorption, translocation, and metabolism of two new, selectively toxic derivatives of carbofuran, 2,3-dihydro-2,2-dimethyl-7-benzofuranyl (di-n-butylaminosulfenyl)(methyl)carbamate and 2,3-dihydro-2,2-dimethyl-7-benzofuranyl (morpholinosulfenyl)(methyl)carbamate, were studied in cotton and corn plants 1, 3, 6, and 10 days following both stem injection and foliage treatment. Both carbamates were readily translocated to all plant parts following stem injection, but translocation following leaf application was restricted to within the leaf. In cotton plants, the dibutylaminosulfenyl derivative was easily hydrolyzed to form carbofuran which, in turn, was oxidized at the 3-position of the ring and the N-methyl group. These oxidized metabolites were then converted to plant conjugates. Major metabolites were carbofuran and 3-hydroxy-carbofuran followed by 3-keto-carbofuran phenol and N-hydroxymethyl-carbofuran. Five minor metabolites also were detected. In corn plants, the dibutylaminosulfenyl derivative gave the same metabolites, although the metabolism rate was significantly slower in corn relative to cotton. Overall, the results showed that there were no fundamental differences in the metabolism of the morpholinosulfenyl and dibutylaminosulfenyl derivatives. The stability of both carbamate derivatives in different solvent systems also was investigated. 相似文献