Rapid identification of chemical constituents and dynamic metabolic profile of Shenqi-Tiaoshen formula in rat plasma based on UPLC-Q-TOF/MSE

Shenqi-Tiaoshen formula (SQTSF) is a traditional Chinese medicine (TCM) prescription that has been employed in the treatment of chronic obstructive pulmonary disease (COPD). Clinical practice has demonstrated that SQTSF is an effective prescription for stable COPD. However, owing to the complexity of TCM prescription, there is a lack of in-depth understanding of the chemical components of SQTSF and its in vivo metabolism studies. In this study, a comprehensive analytical strategy based on ultra-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF/MS) was established to identify the chemical components, the absorbed components, and the metabolites of SQTSF given by gavage in rats, and analyze their dynamic changes. As a result, 86 chemical components of SQTSF were characterized, which were mainly categorized into flavonoids, saponins, organic acids, terpenoids, etc. Among them, 13 compounds were confirmed unambiguously by reference standards. Furthermore, 20 prototype components and 46 metabolites were detected in rat plasma at different time points. It was found that one prototype component and thirteen metabolites could be detected during the entire 24 h, indicating that these compounds were slowly eliminated and thus accumulated in vivo over a prolonged duration. Interestingly, the phenomenon that three prototype components and fourteen metabolites reappeared after a period of disappearance from the plasma was found. It was also observed that different prototype components may generate the same metabolite. The metabolic processes of SQTSF in rats mainly included oxidation, reduction, hydration, demethylation, deglycosylation, methylation, acetylation, glucuronidation, glutathionylation, and associated combination reactions. Overall, the present study identified the chemical components of SQTSF and their dynamic metabolic profile in rat plasma, which provided a systematic and applicable strategy for screening and characterization of the prototype components and metabolites of TCM compound preparations.