DEP (Falone,2,4-Dichlorophenoxyethyl phosphite) 
In the presence of moisture, DEP underwent hydrolysis with formation 
of inorganic phosphate and 2,4-dichlorophenoxethanol. This could then 
undergo oxidation to 2,4-D (Feldman, undated; Sheets and Danielson, 1960). 
“CHSCH,O 0 CH,CH,OH 
Cl p Cl + H3P03 
3 oO 
CHyC 
2s 
Cl Cho NA ‘a 
3 2,4-Dichloro- 
phenoxy Ethanol 
DEP 
Ci 
2,4-D 
DFP (Diisopropoxyphosphoryl fluoride) 
Studies showed that a DFPase was present in mammals and that it was 
capable of splitting the P-F bond and releasing HF. Phosphorylation of the 
serine moiety of the enzyme occurred simultaneously, (Mazur, 1946; Mazur 
and Bodansky, 1946; Nachmansohn, 1947; Jansen et al., 1949; Kilby, 1953; 
Mounter et al., 1953; Mounter, 1954; Augustinsson, 1954; Augustinsson and 
Casida, 1959). 
“a 
ee er : RX 
Scno}-P-F + ‘ Ng Rr ee ‘Noo + HF 
CH; NE ek A 
2 0” \R o” Sr’ 
DFP 
84 
