QUINMERAC

Chemical Properties

Crystalline Solid

Uses

Herbicide.

Uses

Auxin-type herbicide.

Definition

ChEBI: A quinolinemonocarboxylic acid that is quinoline-8-carboxylic acid carrying additional methyl and chloro substituents at positions 3 and 7 respectively. A residual herbicide used to control broad-leaved weeds on a range of crops including cereals, rape and beet.

Environmental Fate

In the field, the DT₅₀ of quinmerac may range from 3 to 33 days. Losses due to volatilization are negligible. Soil moisture conditions greatly influence quinmerac persistence by moderating microbial degradation and soil leaching. Quinmerac is only slightly adsorbed to the soil.

Metabolism

Chemical. Quinmerac is stable to heat, light, and in aqueous solutions with pH values between 3 and 9.
Plant. The degradation and metabolic pathways of quinmerac have not been extensively studied. In plants, oxidation of the 3-methyl group to the alcohol and hydroxylation at the 2-quinoline position are the major metabolism reactions (56). These quinmerac metabolites are subsequently conjugated to carbohydrates. The quantity of quinmerac metabolized varies among species, ranging from 5% to 80% (56).
Soil. In the soil, degradation of quinmerac was similar to that observed in plants, resulting in the same oxygenated and hydroxylated metabolites.

Toxicity evaluation

Quinmerac is excreted in the urine of mammals and appears to remain primarily unmodified. The acute oral LD₅₀ in rat is >5000 mg/kg.