Coumaphos system

De Vaney, J.A. and G.W. Ivie. 1980. Systemic activity of coumaphos, famphur, crufomate, ronnel, and phosmet given orally to hens for control of the northern fowl mite, Omithonyssus sylviarum (Canestrini and Fanzago). Poult. Sci. 59 1208-1210. 

The hydrolysed material was then subjected to U.V.-ozonation (Panel B). Samples were taken at various times and remaining in the material was determined by liquid scintillation counting. Samples were diluted 1 10 with methanol and subjected to HPLC in a solvent system of methanol in phosphoric acid to determine coumaphos (A) and chlorferon (B) levels. 

Coumarin insecticides usually contain the coumarin molecule with an 0,0-diethyl phosphate or 0,0-diethyl phosphothionate radical, e.g. Potasan, (0,0 diethyl-0-(4-methyl-7-coumaryl)phosphothionate) (111) Coumaphos, (0,0 diethyl-0-(3-chloro-4-methyl-7-coumaryl) phosphothionate (112) Haloxon, (0,0-diethyl-O-(3-chloro-4-methyl-7-coumaryl) phosphate (113). The mode of action of these compounds combines the toxic properties of coumarin moiety with the action of the organophosphorus compounds. The latter acts by inhibiting the esterase enzyme systems in the insects, particularly cholinesterase, probably by phosphorylation of the active site of the enzyme. 

---