Species differences in the metabolism of hycanthone

The rate of excretion of labelled hycanthone has been determined in bile and urine from three strains of rats (Sprague-Dawley, hooded and Gunn), and from dogs, cats, rabbits and monkeys. Bile was the major route of excretion in all species; the half-life for excretion of total radioactivity ranged from 1.6 to 3.0 hours. Relatively little of the radioactivity was found in the urine, except in the monkey and notably in the cat. Most of the radioactivity in the bile and urine was found in conjugated form, or as polar metabolites; cat urine, however contained a high percentage of hycanthone and less polar metabolites. Some fifteen metabolites have been seen in bile, and/or urine, and nine from in vitro incubations with microsomal preparations. Five of these, including hycanthone, have been chemically characterized, and two others tentatively identified.