
Dicamba (Banvel D) [2-Methoxy-3,6-dichlorobenzoic acid] 
Dicamba was rapidly excreted by rats after injection or oral admini- 
stration, unchanged and as the glucuronic acid conjugate (1437). 
The metabolism of dicamba by wheat (var. Gaines) and bluegrass (var. 
Newport) plants yielded three metabolites. Paper chromatography was used 
to separate and detect the metabolites. Gas liquid chromatography, infra~ 
red and mass spectrometry were used to identify the major (90%) metabolite 
as 5-hydroxy-2-methoxy-3,6-dichlorobenzoic acid. After hydrolysis by s- 
glucosidase, one of the minor (5%) residues was identified as dicamba. The 
second minor (5%) metabolite was identified as 3,6-dichlorobenzoic acid (182). 
Roots of plants which had been incubated with dicamba were homogenized 
and analyzed. Gas chromatography of propyl and butyl derivatives showed 
that 5-hydroxy-dicamba was a major metabolite in treated com roots and 
that 3,6-dichlorosalicylic acid was a minor metabolite in treated roots 
of both com (Zea) and barley (Hordeum). The data also indicated that 5- 
hydroxy-dicamba and 3,6-dichlorogentisic acid were major metabolites in 
young barley plants treated with dicamba (1196). 
Studies have shown that microbial or chemical decomposition of dicamba 
in soil was more important that volatilization (209). 
Dicamba moved readily in soil water, suggesting limited adsorption (498). 
Studies have indicated that dicamba exerted its effects by inhibiting 
pantothenate synthesis at the level of conversion of ketopantoate to 
pantoate (659). 
At 200°C dicamba decarboxylated to give 2,5-dichloroanisole (1761). 
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