Imazaquin acid

The Uses of Imazaquin acid

Agricultural chemical.

Definition

ChEBI: 2-[4-methyl-5-oxo-4-(propan-2-yl)-4,5-dihydro-1H-imidazol-2-yl]quinoline-3-carboxylic acid is a quinolinemonocarboxylic acid that is quinoline-3-carboxylic acid which is substituted by a 4-methyl-5-oxo-4-(propan-2-yl)-4,5-dihydro-1H-imidazol-2-yl group at position 2. It is a quinolinemonocarboxylic acid, an imidazolone and a monocarboxylic acid.

Hazard

Moderately toxic by ingestion and skin contact. Low toxicity by inhalation.

Pharmacology

Plant Metabolism. The selectivity of imazaquin is due to differential rates and routes of metabolism in tolerant crops versus susceptible weeds (3). The primary metabolite in soybeans is a pyrroloquinoline acetamide (41, Fig. 18), which is immobile in the plant and is not an inhibitor of acetolactate synthase. This metabolite is further broken down to eventually yield a dicarboxylic acid.
Animal Metabolism. Metabolism studies in the rat showed that they rapidly excreted unchanged imazaquin in the urine (5). There was no accumulation of imazaquin or any of its derivatives in the liver, kidney, muscle, fat, or blood. There was no detectable residue in the liver, kidney, muscle, or fat of lactating goats and laying hens, which were fed imazaquin for 7 consecutive days (5).

Metabolism

Imazaquin kills plants by inhibiting acetolactate synthase (ALS) (I50 = 1 μM), which is the first common enzyme in the biosynthesis of the branched chain amino acids, valine, leucine, and isoleucine. Imazaquin is rapidly absorbed through the roots of plants. Once it enters the plant, imazaquin rapidly translocates to the growing points and growth ceases within 1 day after herbicide application followed by chlorosis and then necrosis of the growing points. Total plant death will occur within 2 to 3 weeks after treatment.

Toxicity evaluation

Imazaquin has shown no mutagenic or genotoxic activity in the Ames assay, mammalian cell gene mutation assay, in vitro chromosome aberration assay, in vitro unscheduled DNA synthesis (URS) assay, or the in vivo dominant lethal assay in male rats. This herbicide also has a low potential for bioaccumulation in fish.