Metabolite profiling and quantification of phytochemicals of Tianma–Gouteng granule in human and rat urine using ultra high performance liquid chromatography coupled with tandem mass spectrometry

Abstract Tianma–Gouteng granule has been used for the treatment of hypertension, headache, and stroke in China. However, the metabolism of Tianma–Gouteng granule has not been clear. In the present study, an ultra high performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry method has been developed for rapid identification of 35 prototypes and 43 metabolites in human and rat urine after single oral administration of Tianma–Gouteng granule. The results showed that glucuronidation and sulfation were the main metabolic pathways for flavonoids, alkaloids, iridoidic glycosides, anthraquinones, phenols, and stilbenes that were found in Tianma–Gouteng granule. Moreover, a validated ultra high performance liquid chromatography coupled with tandem mass spectrometry method was applied for the quantification of 14 compounds in rat urine after an oral administration of Tianma–Gouteng granule (2.5 g/kg). During 0–48 h after dosing, the cumulative excretion rates of nine prototype components were 53% for gastrodin, 0.07∼1.6% for geniposide, baicalin and baicalein, wogonoside, rhynchophylline and isorhynchophylline, leonurine, and emodin, indicating that urinary excretion is the major way for gastrodin to eliminate from the body. This study provides a comprehensive understanding of metabolism and excretive kinetics of Tianma–Gouteng granule in human and/or rat, and helpful information for screening of its active components in vivo and clinical application.