Abstract
The life of m-tolyl N-methylcarbamate (Tsumacide®) in rat body is very short. Depending on the sex, from 78 to 96.6%, of an administered dose of 14C-Tsumacide is eliminated in the urine by 24hr after treatment. In rats, Tsumacide is mainly metabolized by oxidative reactions at m-methyl group and 4-position of the aromatic ring. Hydrolysis of the ester linkage occurs only to a minor extent. The resulting oxidation products and phenols are partly conjugated as sulfate and glucuronides. The major metabolic pathways are identical in male and female rats.
From 78.7 to 85.8% of the radiocarbon is rapidly lost from the bean plants treated with 14C-Tsumacide and -Meobal by 24hr after treatment. Approximately 70% of the dose is also lost within 24hr after topical application of 14C-Tsumacide to houseflies. Oxidation of m-methyl group, N-methyl group and the aromatic ring at 4-position occurs with Tsumacide in houseflies and bean plants. Meobal undergoes hydroxylation at 4-methyl group and N-methyl group in bean plants. The oxidation products are conjugated as glucuronide and glucoside in houseflies and as glucosides in bean plants.
Tsumacide metabolites formed by oxidation are less active than the original compound in anticholinesterase activity.
