Amitrole (AT, ATA, 3-AT, Aminotriazole) (3~Amino-1,2,4-triazole) 
Labeled amitrole (Ghaminosine Goreiaretesssce) was fed to rats. 
Analysis for radioactivity showed only traces of cl4 in expired air. 
Seventy to ninety-five percent of the activity appeared in the urine within 
24 hours as two unidentified metabolites and unchanged amitrole (430). 
Tests indicated that 3-acetamido-1,2,4-triazole was not present (432). 
Feces contained small variable amounts of activity. After the first day, 
most internal organs exhibited some activity. No free amitrole was found 
in the liver. The average half-time for ATA clearance in various organs 
was 4.2 hours (3.4 to 5.1). 
Studies have been conducted with amitrole applied to plants (251, 255, 
652, 765, 1108), but metabolites were not identified. Other studies indicated 
that amitrole was activated to form a free radical, which was then capable 
of reacting with amino acids (233, 234, 235, 652, 654, 1005). Complexes of 
amitrole and alanine, glycine, or serine have been reported (230, 231, 232, 
926, 927, 931, 933, 964, 1075, 1229, 1230). Infrared absorption spectral 
analyses and biochemical studies have also indicated that an amine glucoside 
was formed (411, 484, 485, 486, 487, 534) and that the amitrole-glucoside 
could be phosphorylated by yeast (488). In experiments with Abies concolor 
and Pinus ponderosa, amitrole was converted into three metabolic products, 
one of which seemed to be ATA-alanine (913). 
Recent studies showed that the reproductive and vegetative structures 
of the bean plant, Phaseolus vulgaris, differed in their metabolism of 
amitrole. Vegetative parts formed stable complexes with the parent compound, 
whereas young reproductive organs cleaved the ring structure of amitrole and 
incorporated the carbon into common biochemical compounds such as, glucose, 
sucrose, fructose, and other compounds (1296). Bean plants transferred large 
quantities of C** from serine cl4 to 3-amino-1,2,4-triazolyl>j—alanine (3- 
ATAL) in both light and dark studies. Carbon from alanine cl ,» and formate- 
cl4, also entered 3-ATAIL but the percentage of conversion was far greater 
for serine. Yeast (Saccharmoyces cerevisiae) did not form 3-ATAL from 3-AT 
in 72 hours of incubation. 
Toxicity of amitrole has been correlated with chemical analyses and 
it was found that biological response is proportional to the amount recover- 
able from soils (484, 1372). Studies have shown that amitrole not only 
partakes in the soil's base exchange system but that it also tends to form 
complexes with metals (249, 353, 354, 411, 1075). 
The major metabolic product formed from amitrole by microbiological 
activity was carbon dioxide. At least thirteen additional unidentified 
compounds were also formed (38, 1210). E. coli converted 3-ATA into a 
metabolite, 3-amino-1,2,4,-triazolyl alanine. This was incorporated into 
cellular protein (1501). Studies with yeast showed that imidazolegylcerol 
phosphate accumulated, presumably because of histidine biosynthesis 
inhibition (662, 804, 1492). 
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