Synthesis and herbicidal activity of the optical isomers of O-ethyl O-2-nitro-5-methylphenyl N-isopropyl phosphoramidothioate.

Decomposition and Leaching of Radioactive Sumithion in 4 Different Soils under Laboratory Conditions

“…Thus, under upland condition 2 major degradation products of Sumithion are 3-methyl-4-nitrophenol and radioactive carbon dioxide (Table 5) In every condition oxidation products of Sumithion other than carbon dioxide have never been detected such as sumioxon, carboxysumithion and desmethylsumioxon present in mammals239) and/or among photoproducts. 19 So, reduction and hydrolysis are major degradation pathways of Sumithion in soil and in soil microorganisms, in accord with the pevious investigations.l5> Decomposition pathways for Sumithion under these conditions can be proposed as in Fig. 3.…”

Metabolism of Chiral Isomers of Isofenphos in the Rat Liver Microsomal System

“…It was proved that the insect toxicity of chiral cyanofenphos and fonofos paralleled with the amount of active metabolite(s) produced from each chiral isomer. 3,6,9) In the present experiment, chirality affected the production amount of isofenphos-oxon. As shown in the previous paper on the in vitro metabolism of isofenphos in the rat, however, none of benzene soluble metabolites containing unknown I and II inhibited AChE at a concentration of 10-7 M,7) although aminoisof enphos-oxon has been proposed as an active metabolite by Heppner et al 10) and Gorder et al 11) Therefore, stereoselectivity in insecticidal activity of isofenphos was not explained sufficiently by the result obtained from the metabolism study of chiral isofenphos in the microsomal NADPH system, and the difference of affinity with ACNE between bioactivated chiral isomers remains to be clarified.…”

“…3) Moreover, it was found that stereoselectivity was dependent on the different metabolism of chiral isomers in organophosphorus compounds, such as S-2571 (0-ethyl 0-2-nitrophenyl isopropylphosphoramidothioate), EPN (0-ethyl 0-p-nitrophenyl phenylphosphonothioate) and fonofos (0-ethyl S-phenyl ethylphosphonodithioate). [4][5][6] This report is concerned with differential metabolism of the chiral isomers of isofenphos in the rat liver microsomal system.…”

Metabolism of Fenitrothion in the Organophosphorus-Resistant and -Susceptible Strains of Rice Stem Borers, <i>Chilo suppressalis</i>

“…The methods based on those of Ohkawa et al 16' was used to study the metabolism of [ring-14C]fenitrothion. Individual larvae of the Hata and S strains were topically treated with 0.1 ug of [ring-14C] f enitrothion in 0.5 4cl of acetone.…”