A systematic profiling of chemicalome and metabolome of Citrus aurantium 'Changshan-huyou' flavonoids to provide insights into its potential in vivo pharmacodynamic material basis.

Citrus aurantium 'Changshan-huyou', as an authentic geo-characteristic Chinese medicinal material, has shown promising therapeutic potential for metabolic disorders. Although the abundant flavonoid constituents have been demonstrated as its main active substances, it is never an easy task for systematic profiling of its chemical constituents (chemicalome) and in vivo biotransformed metabolites (metabolome). Therefore, the unclear in vivo pharmacodynamic material basis of Citrus aurantium 'Changshan-huyou' flavonoids (CACF) is the key bottleneck that limits the full realization of its clinical value. This study used a systematic UPLC-Q-TOF-MS/MS strategy, combined with database mining, fragmentation patterns analysis and diagnostic ions, to comprehensively characterize the chemicalome of CACF. Wistar rats were utilized to collect biological samples (plasma, urine, feces and bile) for the profiling of chemicalome and metabolome. The chemicalome and metabolome of CACF were systematically profiled using a self-established traditional Chinese medicine (TCM) mass spectral database combined (CMSD) with fragment ion similarity-based matching strategy, and a self-established biotransformation rule-based database (BRD) combined with in vivo metabolic reaction annotation The results showed that a total of 148 constituents were identified from CACF, with flavonoids as the predominant class. 39 prototypes and 124 metabolites were detected in plasma, urine, feces and bile, with broadest detection range of CACF constituents observed in rat liver and kidney. The Phase I (oxidation, hydrolysis, etc.) and Phase II (glucuronidation, sulfation, etc.) metabolic pathways were systematically characterized. These findings provide insights into the potential in vivo pharmacodynamic material basis of CACF, which exhibits compositional diversity and metabolic specificity. Structural modification is identified as characteristic of its in vivo metabolic process. Both the chemicalome and metabolome collectively constitute the pharmacodynamic material basis of CACF. Consequently, a scientific rationale is established for understanding the pharmacological basis of CACF.