Identification of the metabolites of TCM prescription Sinisan, found in miniature pig urine via intragastric administration

Abstract The metabolic profile of the traditional Chinese medicine, Sinisan, in miniature pig urine via intragastric administration was investigated. In total, 50 compounds, including 10 unchanged parent glycosides, which were not found from Sinisan's metabolic profile in rats’ urine, were identified. Among these, 36 compounds were characterized by HPLC–SPE–NMR coupled with HPLC–HRESIMS, five of which are new and nine are endogenous metabolites of miniature pig. Most of phase I and phase II metabolites are hydrolytic products of parent glycosides and glucuronide conjugates, respectively, the latter having been reported as sulfate conjugates while the experimental animal is rat. Benzoic acid, obtained from hydrolysis of albiflorin and paeoniflorin, and phenylpropenoic acids, obtained from oxidative cleavage of flavones, formed phase II glycine conjugates.