The metabolism of 4-(4-hydroxyphenyl)butan-2-one (raspberry ketone) in rats, guinea-pigs and rabbits.

1. The metabolism of 4-(4-hydroxyphenyl)butan-2-one(raspberry ketone) was studied in rats, guinea-pigs and rabbits. 2. Following intragastric dosage (1 mmol/kg) urinary metabolite excretion was nearly complete within 24 h, amounting to roughly 90% of the dose in all species. 3. The most prominent urinary metabolites were raspberry ketone and its corresponding carbinol, both largely conjugated with glucuronic acid and/or sulphate. The extent of ketone reduction was greatest in rabbits. 4. Oxidative metabolism included ring hydroxylation and side-chain oxidation. The latter pathway led to 1,2- and 2,3-diol derivatives. It is proposed that the latter undergo cleavage to furnish the C6-C3 and C6-C2 derivatives detected.