Hydrolysis phosphorothiolate

The phosphate products may be measured in urine as bioindicators of exposure to organophosphates. The product that is observed depends on whether or not oxidative desulfuration occurs prior to esterase hydrolysis of the molecules. These products have been studied in the urine of greenhouse workers exposed to three methyl organophosphate esters toclofos-methyl (Figure 18.9), feni-trothion (Figure 18.9), and omethoate, a phosphorothiolate compound (below)14 ... 

A study of the hydrolysis of the cis-methyl ester of 3 -deoxy-3 -thiothymidine 3 -S,5 -0-cyclic(phosphorothiolate)is referred to in Chapter 7. 

The hydrolysis of the cyclic phosphorothiolate 281 has been studied between pH —2 and pH 7.6. Below pH 2, the products 282 and 283 were obtained with 283 predominating, whereas between pH 2 and pH 5, the cyclic phosphorothiolate 282 was the main product. Above pH 5, 283 and 284 were obtained, with the latter predominating by 2 1. Mechanisms were discussed, with the uncatalysed reaction to give 282 occurring through attack of water on the methyl group, with C-O bond cleavage. ... 

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