Urinary metabolites of orally administered di-(5-hexenyl) phthalate and di-(9-decenyl) phthalate in the rat.

Di-(5-hexenyl)- and di-(9-decenyl) phthalates were administered to male CD rats by gavage. The urinary metabolites retaining the phthalate moiety were identified by chromatographic and mass-spectrometric techniques. Di-(5-hexenyl) phthalate gave rise to epoxide and vicinal diol metabolites not previously seen with phthalic acid esters of saturated alcohols. Neither epoxide nor diol were detected when di-(9-decenyl) phthalate was fed. The distributions of carboxyl-terminated metabolites suggested that somewhat different pathways were followed for the two test compounds. The formation of epoxides from these unsaturated phthalate esters may have relevance to their potential toxicities. Like the metabolites of di-n-butyl phthalate, the metabolites of di-(5-hexenyl) phthalate included glucuronide conjugates; like the metabolites of di-(2-ethylhexyl) phthalate, those of di-(9-decenyl) phthalate did not.