METABOLISM OF TETRAMETHRIN ISOMERS IN RAT .1. IDENTIFICATION OF A SULFONIC-ACID TYPE OF CONJUGATE AND REDUCED METABOLITES

1. Urinary and faecal metabolites in rat treated with C-14-labelled (1 RS, trans)tetramethrin [3,4,5,6-tetrahydrophthalimidomethyl (1RS, tran s)-chrysanthemate] were identified using chromatographic techniques an d spectroanalyses (nmr and ms). 2. 3-Hydroxy-cyclohexane-1,2-dicarboxi mide was found to be a major and unique urinary metabolite, reduced at the 1,2-double bond of the 3,4,5,6-tetrahydrophthalimide moiety. 3. T he major faecal metabolites were sulphonic acid conjugates, having a s ulphonic acid group incorporated into the double bond of the 3,4,5,6-t etrahydrophthalimide moiety. 4. On the basis of the metabolites identi fied here, the major biotransformation reactions of trans-tetramethrin in ran are: (1) cleavage of the ester linkage; (2) cleavage of the im ide linkage; (3) hydroxylation of the cyclohexene or cyclohexane ring of the 3,4,5,6-tetrahydrophthalimide moiety; (4) oxidation at the meth yl group of the isobutenyl moiety; (5) reduction at the 1,2-double bon d of the 3,4,5,6-tetrahydrophthalimide moiety; and (6) incorporation o f a sulphonic acid group into the 1,2-double bond of the 3,4,5,6-tetra hydrophthalimide moiety.