Demeton (Systox, Bayer 19639) 
(I) 0,0-Diethyl S-ethyl-2-thioethyl phosphorothiolate (also known 
as Isosystox or Demeton S) 
(II) 0,0-Diethyl O-ethyl-2-thioethyl phosphorothioate (also known 
as systox thiono isomer or Demeton 0) 
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II Ceveeone heaves teeta dem 
Investigations of the two isomers have been carried out by use of ps2 
radiotracers, by chromatography, and by infrared spectrophotometry. The 
data obtained showed that these isomers were metabolized in the same manner 
in fruits, beans, and cotton. Seven days after application of demeton 0, 
only traces of the isomer were present. All radioactivity on the chroma- 
tograms corresponded to the sulfoxide and sulfone (Metcalf et al., 1954, 
1955; Jucker, 1958; Niessen et al., 1962). Demeton O also underwent 
isomerization in plants and gave rise to three unidentified compounds 
(Hartley, 1952a; Henglein and Schrader, 1955; Muhlmann and Tietz, 1956). 
With mice, the administered dose is rapidly absorbed, metabolized, 
and eliminated. Only 6% or less was found in the stomach after 1 to 2 
hours; and, after 4 hours, it has almost entirely disappeared from these 
tissues. Small amounts passed through the intestines but most was 
eliminated in the urine rather than the feces. The major site of degra- 
dation was the liver and degradation continued until elimination in the 
urine (March et al., 1955). 
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