Phosphamidon (1-Chloro-1-diethylcarbamoyl-1-propen-2yl dimethyl phosphate) 
Studies with labeled phosphamidon show that plants metabolize phos- 
phamidon to desethylphosphamidon, dimethyl phosphoric acid, a-chloro- 
acetoacetate diethyl amide, and a-chloroacetoacetate ethylamide (Jaques 
and Bein, 1960; Anliker et al., 1961; Menzer and Ditman, 1963). 
CH C1 Cl 9 9 
CH,0- -o-t==c-& Cols > c1s-g-ba-& f2i5 + (CH30) 9 -P-0# 
OCH 0 
3 CoHs Nog Hs | 
— | HPO, 
: 8 CH3 Cl 0 Ce Y Q 
CH30-P-O-C==C-C HH ———Se H3-¢-CH-G & (one 
bcHy ne 0 nN CH3 
CoHs Cy Hs 
Desethyl phosphamidon 
Phygon (Dichlone) (2,3-Dichloro-1,4-naphthoquinone) 
Experiments indicated that the key oxidations of glucose, acetate, 
pyruvate, and a-ketoglutarate were inhibited by phygon. Since coenzyme A 
is the only factor common to all these reactions, the data strongly indi- 
cated that coenzyme A was inactivated. Other studies have also shown that 
phygon inhibits enzymes with free sulfhydryl groups. Whether subsequent 
degradation of the CoA complex occurs is not now known (Owens and Novotny, 
1958; McNew and Burchfield, 1951; Owens and Blaak, 1960). 
Cl “S-CoA 
iD 
Phygon 
137 
