An Integrated UHPLC-Q-Orbitrap-MS/MS and In Vitro Gastrointestinal Simulation Strategy for Characterizing the Chemical Constituents and Metabolites of Shaoyao RuanGan Decoction

Shaoyao Ruangan Decoction (SYRGD), a classic traditional Chinese medicine (TCM) preparation composed of over a dozen herbs, is widely used in the clinical treatment of liver cancer, hepatitis, and liver cirrhosis. In this study, we elucidated the chemical basis of SYRGD and, for the first time, its in vivo metabolic pathways and dynamic gastrointestinal changes by combining ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-Q-Orbitrap-MS/MS) with the Simulator of the Human Intestinal Microbial Ecosystem (SHIME) model. Results revealed the identification of 101 constituents in SYRGD, primarily including flavonoids, terpenoids, organic acids, and alkaloids. Within the SHIME digestive fluids, 69 prototype components and 67 metabolites were identified, with the metabolic pathways primarily involving hydroxylation, oxidation, sulfation, and glucuronidation. Dynamic analysis showed that most prototype components were gradually absorbed or transformed, exhibiting a decreasing concentration gradient from the stomach to the colon. In contrast, many metabolites showed significant enrichment in the stomach and small intestine prior to their absorption or further transformation, indicating that metabolic reactions occurred throughout the entire digestive process. This study provides a comprehensive reference for the clinical application and further development of SYRGD. The systematic methodology is rapid, reproducible, overcomes the limitations of conventional animal or clinical trials, and establishes a precise research strategy for investigating the metabolism of other complex herbal medicines.