Identification and determination of glutathione and glucuronide conjugates formed from butylated hydroxytoluene in rats.

Abstract

Rats which had received butylated hydroxytoluene (BHT) excreted S-(3,5-di-tert-butyl-4-hydroxybenzyl)glutathione (BHT)-glutathione) and 3,5-di-tert-butylhydroquinone (BHQ) glucuronide in the bile. After being separated by high-performance liquid chromatography, the glutathione conjugate was identified by 13C-NMR and field desorption mass spectrometry; the glucuronide was identified by gas chromatography-mass spectrometry; The structures of BHT-glutathione and BHQ glucuronide were further confirmed by comparison with synthetic samples. The excretion rates of BHT-glutathione and BHQ glucuronide in rat bile were 3.5 and 1.6%, respectively, of the dose in 24 h after i.p. administration of BHT 400 mg/kg. The occurrence of BHT-glutathione suggested that 2,6-di-tert-butyl-4-methylene-2,5-cyclohexadienone, a toxic metabolite of BHT, was detoxified by glutathione conjugation.