METABOLISM OF TETRAMETHRIN ISOMERS IN RAT .3. STEREOCHEMISTRY OF REDUCED METABOLITES

1. Three main urinary metabolites, true isomers of 3-hydroxycyclohexan e-1,2-dicarboximide (3-OH-HPI-1 and 2) and 1,2-tetrahydrodicarboxylic acid (TCDA) were purified from rat treated with (1RS, trans)-tetrameth rin [3,4,5,6-tetrahydrophthalimidomethyl(1RS, trans)-chrysanthemate]. 2. To elucidate the mechanism of formation of these reduced metabolite s, the stereochemistry of 3-OH-HPI-1, 3-OH-HPI-2 and TCDA was clarifie d by chemical reactions, spectroanalysis (nmr) and X-ray analysis. 3. The sole difference in configuration between 3-OH-HPI-1 and 3-OH-HPI-2 was found to be the orientation of the hydroxyl group to the cyclohex ane ring, and both of these reduced metabolites showed cis-addition of two hydrogens. In contrast, reduction resulted in the trans form with TCDA. 4. These findings indicate the existence of two different reduc tion reaction mechanisms in the rat.