The Enantioselective Metabolism of 4-Isopropenyltoluene in Rabbits

Abstract

4-Isopropenyltoluene (8) was administered orally to rabbits and the following four optically active metabolites, 2-(p-tolyl) propanoic acid (10), p-(1-carboxyethyl) benzoic acid (11), 2-hydroxy-2-(p-tolyl) propanoic acid (12), and 2-(p-tolyl)-1, 2-propanediol (13) were isolated from urine in addition to an optically inactive metabolite, 4-isopropenylbenzoic acid (9). The enantiomeric ratios of the metabolites 10 and 11 were respectively R/S=33 : 67 and 39 : 61 (S predominance), whereas those of the metabolites 12 and 13 possessing a tertiary hydroxyl group were R/S=77 : 23 and 84 : 16 respectively (R predominance). The presumed metabolic pathways of 8 in rabbits leading to these metabolites are discussed.