The metabolism of C¹⁴-α-tocopheryl quinone and C¹⁴-α-tocopheryl hydroquinone

The metabolism of C¹⁴-d-α-tocopheryl quinone (α-TQ) and its hydroquinone (αTHQ) was investigated. Forty-six hours after intraperitoneal administration of either compound to rats the radioactivity isolated from the liver was present almost exclusively in C¹⁴-α-TQ. The results indicated, however, that in situ this compound was present primarily in the reduced form. No conversion to C¹⁴-α-tocopherol or other liver metabolites was observed. α-THQ was eliminated from the tissues more rapidly than α-TQ. The main metabolite excreted in the urine was a conjugate of α-tocopheronic acid and the main metabolite excreted in the feces was a conjugate of α-TQ. Free C¹⁴-α-TQ was present in the feces after administration of this compound but not after C¹⁴-α-THQ administration.