Mammalian metabolism of terpenoids. I. Reduction and hydroxylation of camphor and related compounds.
Drug Metab Dispos 1973 Mar; 1(2):543-551
The metabolism of D-camphor (464493), L-camphor (464482), and some related compounds was investigated in-vivo in the dog and rabbit, and in-vitro in liver preparations from rats and rabbits. A male beagle-dog was given 1 gram (g) of D-camphor four times a day for 7 days. A white New-Zealand-rabbit was given a suspension of 300 milligrams of D-camphor by stomach tube, and urine was collected for 24 hours. Both the dog and the rabbit excreted three hydroxycamphors in the urine: 5-exo-hydroxycamphor, 5-endo- hydroxycamphor, and a 3-hydroxycamphor identical in thin layer and gas chromatographic characteristics with 3-endo-hydroxycamphor. The metabolism of L-camphor proceeded in much the same manner as that of D-camphor. However, in the reductive metabolism of the two camphor isomers there were some significant differences. No reduction of D- camphor was noted in rat liver 9000g supernatant fraction, but a modest extent of reduction of L-camphor occurred in this preparation. The major form was the endoreduction, although the ratio of borneol to isoborneol was much smaller than in the product of reduction of D-camphor by the analogous rabbit liver fraction. In the rabbit liver 9000g supernatant fraction, reduction of the 20- keto group of L-camphor occurred to a much lesser extent than did that of D-camphor. The stereoselectivity of the reaction was also reversed with isoborneol predominating in the reduction products.
NIOSH-Publication; NIOSH-Grant; Grants-other; Laboratory-animals; Metabolic-study; In-vitro-studies; In-vivo-studies
Pharmacology and Therapeutics Univ of Florida Coll of Med Dept of Pharma & Therapeutics Gainesville, Fla 32601
Other Occupational Concerns; Grants-other
Drug Metabolism and Disposition
University of Florida Gainesville, Gainesville, Florida