Read/Search this Article
As a part of our studies on the metabolic fate of hirsuteine (HT) and hirsutine (HS), the indole alkaloids of Uncaria rhynchophylla, fecal and urinary metabolites of HT and HS were analyzed by a HPLC equipped with a photodiode array detector. Feces samples from rats orally administered HT was found to contain a metabolite. Similarly, feces samples from HS were a metabolite. The metabolites of HT and HS in feces were identified as 11-hydroxyhirusuteine and 11-hydroxyhirusutine by direct comparison with authentic samples on HPLC, respectively. The parent compound was detected from only feces samples from HT. Total cumulative fecal excretion during 72h after the oral administration of HT and HS was approximately 7% and 8%, respectively. On the other hand, urinary excretion during 24h after the intravenous administration of HT and HS was approximately 5% and 12%.