Characterization of the chemical constituents of Jie-Geng-Tang and the metabolites in the serums and lungs of mice after oral administration by LC-Q-TOF-MS

Jie-Geng-Tang (JGT), a traditional formula, is employed in the treatment of sore throat and cough and comprises Platycodonis Radix and Glycyrrhizae Radix et Rhizoma in the ratio 1 : 2. Our previous study demonstrated that JGT protected mice from S. aureus-induced acute lung injury (ALI). Five constituents of JGT showed antibacterial activities against S. aureus in vitro. However, the potential effective constituents of JGT in vivo were still unclear. In this study, the chemical constituents of JGT were identified by liquid chromatography with quadrupole time-of-flight spectrometry (LC-Q-TOF-MS). A total of 96 constituents were identified or assumed, including seven organic acids, 45 flavonoids, 36 triterpene saponins, and eight compounds of other types. The structures of 31 of the constituents were confirmed by comparing them with corresponding authentic standards. Moreover, 15 prototypes and 49 metabolites were deduced in the serums of mice, 24 prototypes and 47 metabolites were deduced in the lungs of mice after the oral administration of JGT. Three types of constituents, namely organic acids, flavonoids, and triterpene saponins, could be absorbed into the blood. Moreover, flavonoids and triterpene saponins were more likely distributed in the lung than in the blood. To the best of our knowledge, this is the first report on the systematic metabolites profile of JGT in vivo. The results reported were beneficial to the elucidation of the effective material basis of JGT.