2,4-D_ and Related Compounds 
4-(2 ,4-DB) [4-(2,4-Dichlorophenoxy) butyric acid] 
In laboratory tests, bluegill (Lepomis gibbosus) converted 
4-(2,4-DB) to 2,4-D (585). When 4-(2,4-DB) was fed to dairy cows, however, 
2,4-D was not found, although it does not decompose in the rumen. The 
‘ major portion of 4-(2,4-DB), therefore, was presumably degraded by a 
mechanism other than f-oxidation in the cow (584, 887). In silage (881, 
882) timothy, birdsfoot trefoil, or pea plants (450), decomposition of 
4-(2,4-DB) has been shown to proceed by f-oxidation. In Bigleaf maple 
(Acer macrophyllum Pursh), the primary oxidation product of 4-(2,4-DB) 
was 2,4-D (1088). 
Studies with 4-(2,4-DB) also showed that it was detoxified by 
Flavobacterium sp. (917), releasing chlorine and cleaving the ring 
’ (206). Aspergillus niger metabolized 4-(2,4-DB) to 2,4-D and four 
unidentified phenolic acids (441). 
After treatment of alfalfa (Medicago sativa L.) with 2,4-DB, 
extracts were analyzed. Metabolites of 2,4-DB (I) as determined by 
gas chromatography included the corresponding dichlorophenoxy- 
caproic (IV) and decanoic (V) acids as well as small amounts of the 
crotonic (II) and acetic (III) acid analogs. Indications of analogs 
with longer side chains than decanoic were also observed (1693). 
4 Cl 
ee 
y, Malonate Ya 
R-CH, -CH,,-CH,, - —————— R-(CH,,) .-C 
2 2 2 ‘ou Addition 2°5 Nou 
I IV 
| + 
~ V4 
R-CH, -CH=CH-C. R- (CH.) 97Xon 
OH 
II V 
+ 
| R-CH, -CH-CH a 
2 on 467) «(OTOH 
+ 0 
70 Alfalfa R-CH,-CY 
ce iG. —_— ‘DH 
: 2,4-D 
III 
115 

