Rapid identification and comparative analysis of the chemical constituents and metabolites ofPhellodendri amurensiscortex and Zhibai dihuang pill by ultra-performance liquid chromatography with quadrupole TOF-MS

Zhibai dihuang pill is a famous traditional Chinese medicine formula containing the herbal medicine Phellodendri amurensis cortex. In this work, an integrative pattern recognition approach including principal component analysis and orthogonal partial least squared discriminant analysis based on ultra-performance liquid chromatography coupled to MS was successfully applied for the rapid discovery of natural compounds from herbal medicines. In a 24 min analysis, 93 compounds were identified or tentatively characterized from Zhibai dihuang pill based on their fragmentation behaviors, 23 of which were from Phellodendri amurensis cortex. A total of 26 metabolites in plasma were identified from Phellodendri amurensis cortex in Zhibai dihuang pill formula, among them, 12 prototypes and 14 metabolites through metabolic pathways of demethylation, methylation, hydrolysis, sulfate conjugation, and glucuronide conjugation, which were seven metabolites more than that of the single drug, suggesting the importance of the compatibility of traditional Chinese medicine. The present study provided important structural information on the metabolism of Zhibai dihuang pill. Furthermore, the results of this work have demonstrated the feasibility of ultra-performance liquid chromatography coupled to MS for the rapid and reliable characterization of metabolites from herbal medicines. Based on these results, this method could be a novel approach for identifying potentially bioactive components in other traditional Chinese medicines.