The metabolism of N-triphenylmethylmorpholine in the dog and rat.

1. Rats were given N-triphenyl[(14)C]methylmorpholine, triphenyl[(14)C]carbinol, N-triphenylmethyl[G-(3)H]morpholine or [G-(3)H]morpholine as single oral doses; the routes of excretion were examined. 2. Dogs were given single oral doses of N-triphenyl[(14)C]methylmorpholine. 3. (14)C-labelled metabolites were excreted mainly in the faeces in both rats and dogs; no (14)CO(2) was expired and less than 3% remained in the carcass and skin after 96hr. 4. (3)H-labelled metabolites were excreted rapidly in urine; part of the label was found in the expired gases and over 10% remained in the carcass and skin after 96hr. 5. Differences in excretion pattern between the sexes were noticed in rats but not in dogs. 6. N-Triphenylmethylmorpholine was rapidly hydrolysed to form triphenylcarbinol and morpholine in the stomach; morpholine was absorbed rapidly and excreted largely unchanged, though some was degraded, since some of the (3)H was found in water. 7. Triphenylcarbinol was absorbed only slowly and was oxidized to p-hydroxyphenyldiphenylcarbinol. 8. Both triphenylcarbinol and its p-hydroxy derivative were found in urine, bile and faeces in the free form and conjugated with glucuronic acid. The proportion of conjugates was higher in rat bile than in faeces. 9. Traces of o-hydroxyphenyldiphenylcarbinol and m-hydroxyphenyldiphenylcarbinol were detected as metabolites both free and conjugated.