0- -0,0-diethyl phosphorothioate

Diazinon is rapidly biotransformed and excreted in mammals. Estimated half-times of diazinon persistence were 6 to 12 h in rats (Anonymous 1972) and dogs (Iverson et al. 1975). Most of the diazinon metabolites were excreted in the urine as diethyl phosphoric add and diethyl phosphorothioic acid in dogs (Iverson et al. 1975), and as hydroxy diazinon and dehydrodiazinon in sheep (Machin et al. 1974). 

The hydrolysis half-life in three different natural waters was approximately 48 d at 25 °C (Macalady and Wolfe, 1985). At 25 °C, the hydrolysis half-lives were 120 d at pH 6.1 and 53 d at pH 7.4. At pH 7.4 and 37.5 °C, the hydrolysis half-life was 13 d (Freed et al, 1979). At 25 °C and a pH range of 1-7, the hydrolysis half-life was about 78 d (Macalady and Wolfe, 1983). However, the alkaline hydrolysis rate of chlorpyrifos in the sediment-sorbed phase were found to be considerably slower (Macalady and Wolfe, 1985). In the pH range of 9-13, 3,5,6-trichloro-2-pyridinol and 0,0-diethyl phosphorothioic acid formed as major hydrolysis products (Macalady and Wolfe, 1983). The hydrolysis half-lives of chlorpyrifos in a sterile 1% ethanoFwater solution at 25 °C and pH values of 4.5, 5.0, 6.0, 7.0, and 8.0 were 11, 11, 7.0, 4.2, and 2.7 wk, respectively (Chapman and Cole, 1982). 

Photolytlc. Malathion absorbs UV light at wavelengths more than 290 nm indicating direct photolysis should occur (Gore et al, 1971). When malathion was exposed to UV light, malathion monoacid, malathion diacid, 0,0-diethyl phosphorothioic acid, dimethyl phosphate, and phosphoric acid were formed (Mosher and Kadoum, 1972). 

The following metabolites were identified in a soil-oat system paraoxon, aminoparathion, 4-nitrophenol, and 4-aminophenol (Lichtenstein, 1980 Lichtenstein et al., 1982). Mick and Dahm (1970) reported that Rhizobium sp. converted 85% [ CJparathion to aminoparathion and 10% diethyl phosphorothioic acid in 1 d. 

Diethyl O-phenyl phosphate, see Parathion Diethyl phosphorothioate, see Phorate 0,0-Diethyl 5 4-nitrophenyl phosphorothioate, see Parathion... 

Diethyl phosphate, see Sulfotepp Diethyl phosphoric acid, see Diazinon. Parathion Diethyl phosphorothioate, see Diazinon 0,0-Diethyl phosphorothioic acid, see Chlorpyrifos, Diazinon. Malathion, Parathion Diethyl sulfide, see Chlorpyrifos Diethyl thiomalate, see Malathion Diethylthiomaleate, see Malathion Diethylthiophosphoric acid, see Diazinon. Parathion Diethyl-0-thiophosphoric acid, see Parathion... 

Based on pseudo-first-order kinetics of phorate hydrolysis, the following half-lives were reported 52 h at pH 5.7, 61 h at pH 8.5, 62 h at pH 9.4, and 33 h at pH 10.25. The major hydrolysis product is ethanethiol which quickly oxidizes to diethyl disulfide. In addition, diethyl dithiophosphate and diethyl phosphorothioate are potential products of phorate hydrolysis (Hong and Pehkonen, 1998). 

Parathion is also metabolized to diethyl phosphorothioic acid and -nitrophenol in a reaction requiring a cytochrome P-4Jg-containing monooxygenase enzyme system (, 4). Studies with H. 0 have indicated that water in addition to molecular oxygen and NADPH is required in this reaction ( ). Diethyl phosphate and -nitro-phenol can also be formed from parathion in a monooxygenase-catalyzed reaction (6). 

Diethyl phosphorothioic acid and diethyl phosphoric acid have been identified as metabolites of [14C]diazinon following a single intravenous injection in female Beagle dogs (Iverson et al. 1975). In vitro metabolism of ethoxy-l-[14C]diazinon was carried out using rat liver microsomes (Yang et al. 1971). Diazinon was metabolized in a complex reaction via cytochrome P-450 to diazoxon and 2-isopropyl -... 

Following an intravenous injection of [ethyl-14C]diazinon to female Beagle dogs, approximately 58% of the radioactivity was recovered in the urine within 24 hours as diethyl phosphorothioic acid (42%) and diethyl phosphoric acid (16%). No intact diazinon was excreted (Iverson et al. 1975). 

Chemical Name 0-(4-bromo-2,5-dichlorophenyl) 0,0-diethyl phosphorothioate... 

Chemical Name S-chlorophenylthio methyl (9,(9-diethyl phosphorothioate... 

Coumaphos 0-(3-chloro-4-methyl 2-oxo-2H-l-benzopyran-7-yl) 0, O-diethyl phosphorothioate Co-Ral... 

On the other hand, parathion can be dearylated by glutathione S-transferase to produce diethyl phosphorothioic acid and S-(p-nitrophenyl) glutathione (Figure 8.22). 

Human erythrocyte AChE inhibited by echothiophate [(2-mercaptoethyl) trimethylammonium-0,0-diethyl-phosphorothioate iodide] was used for in vitro reactivation screening. A compound with three membered carbon linkers (28b) was the most effective from the />-seiies and a compound with seven carbon connecting chains (3 Of Ortho-7) seemed to be the most effective from the o-series. These results were explained by the authors using 3D structures. 

SYNS BRODAN CHLORPYRIFOS-ETHYL CHLORPYRIPHOS CHLORPYRIPHOS-ETHYL DETMOL U.A. 0,0-DIAETHYL-0-3,5,6-TRICHL0R-2-PYRIDYLMONOTHIOPHOSPHAT O.O-DIETHYL O-3,5,6-TRICHLORO-2-PYRIDYL PHOSPHOROTHIOATE DOWCO 179 DURSBAN DURSBAN F ENT 27,311 ERADEX ETHION, dn LORSBAN OMS-0971 PIRIDANE 2-PYRIDINOL, 3,5,6-TRICHLORO-, O-ESTER with O.O-DIETHYL PHOSPHOROTHIOATE PYRINEX STIPEND... 

SYN ACETOPHENONE, 4-HYDROXY-, o-(ISOPROPYLCARBAMOYL)OXIME, o-ESTER WITH 0,0-DIETHYL PHOSPHOROTHIO... 

SYNS 4-BROMO-2.5-DICHLOROPHENOL-0-ESTER mth 0,0-DIETHYL PHOSPHOROTHIOATE 0-(4-BROMO-... 

EN 18133 ENT 25,580 EXPERIMENTAL NEMA-TOCIDE 18,133 NEMAFOS NEMAPHOS NEMA-TOCIDE PHOSPHOROTHIOIC ACID-O.O-DIETHYL-0-2-PYRAZINYL ESTER PYRAZINOL-O-ESTER with 0,0-DIETHYL PHOSPHOROTHIOATE RCRA WASTE NUMBER P404 THIONAZIN ZINOPHOS... 

CHLORO-7-HYDROXY-4-METHYLCOUMARIN BIS(2-CHLOROETHYL)PHOSPHATE see DFH600 3-CHLORO-7-HYDROXY-4-METHYL-COUMARIN-O.O-DIETHYL PHOSPHOROTHIOATE see CNU750 3-CHL0R0-7-HYDR0XY-4-METHYL-C0UMARIN-0-ESTER with 0,0-DIETHYL PHOSPHOROTHIOATE see CNU750... 

CHLORO-4-METHYL-7-COUMARINYL DIETHYL PHOSPHOROTHIOATE see CNU750... 

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