[Elucidation of pharmacodynamic material basis and in vivo metabolites of Longqing Capsules using UPLC-Q-Exactive-Orbitrap-MS technique]

The UPLC-Q-Exactive-Orbitrap-MS technique was employed to investigate the pharmacodynamic material basis of Longqing Capsules and their metabolites in rats, as well as to infer potential metabolic pathways. The contents of Longqing Capsules were prepared into test solutions and administration suspensions for Sprague-Dawley(SD) rats, respectively. After intragastric administration, plasma, urine, and fecal samples were collected at different time points for analysis. Mass spectrometry data were extracted and analyzed by Compound Discoverer 3.3 and Xcalibur 4.1 software. Based on the accurate mass-to-charge ratio, characteristic secondary fragments, reference standards and relevant literature, 128 compounds were identified in Longqing Capsules, including 42 alkaloids, 36 terpenoids, 19 organic acids, 11 flavonoids, 3 acetophenones, 2 limonoids, and 15 other components. Additionally, 144 exogenous compounds were detected in rat plasma, urine, and feces, comprising 61 prototype components and 83 metabolites. The primary metabolic pathways involved oxidation, reduction, hydrolysis, methylation, sulfation, glucuronidation, and composite reactions involving multiple reaction types. This study, for the first time, clarifies the material basis of Longqing Capsules and their metabolic characteristics in rats, providing a reference for research on their pharmacodynamic material basis and quality control.