Cinmethylin

Description

Cinmethylinwas developed by Shell Chemical Company in the early 1980s as a weed control agent for monocotyledonous species. This herbicide controls important grasses such as green foxtail (Setaria viridis) and barnyardgrass (Echinochloa crus-galli) and suppresses the growth of several broadleaf weeds such as prickly sida (Sida spinosa) and velvetleaf (Abutilon theophrasti).

The Uses of Cinmethylin

Cinmethylin is used as pre-emergence grass herbicide. Cinmethylin is member of the cineole eucalyptol family.

Definition

ChEBI: Exo-(+)-cinmethylin is a 1-methyl-2-[(2-methylbenzyl)oxy]-4-(propan-2-yl)-7-oxabicyclo[2.2.1]heptane that is the exo-(+)-isomer of cinmethylin. It is an enantiomer of an exo-(-)-cinmethylin.

Pharmacology

Cinmethylin is active on several important grasses in rice (Echinochloa spp., Cyperus spp., and Monochoria vaginalis) at rates from 25 to 100 g ai/ha (5). Its chemical and toxicological features (low persistence in environment and low mammalian toxicity) generated a significant level of interest in its use as a rice herbicide.

Metabolic pathway

When rats are administered 14C-cinmethylin orally, the major route of its elimination is via urinary excretion. A complex degradation pattern of cinmethylin is observed and the metabolic pathways involve hydroxylation, oxidation at the benzyl and cineol portions, conjugation with glucuronic acid and glycine, and cleavage of the ether linkage. When rats are administered 14C-cinmethylin by stomach incubation, two minor metabolites are identified as o- (acetoxymethyl)benzoic acid and 9-(acetoxymethyl)-a- carboxycinmethylin.