Fragment ion diagnostic strategies for the comprehensive identification of chemical profile of Gui-Zhi-Tang by integrating high-resolution MS, multiple-stage MS and UV information

Gui-Zhi-Tang was considered to be the most famous formula in Shang-Han-Lun, treating 32 symptoms of disease after adding up or cutting down crude drugs. The chemical constituents in Gui-Zhi-Tang were comprehensively studied by rapid resolution liquid chromatography quadrupole time-of-flight mass spectrometry (RRLC-Q-TOF-MS) combined with rapid resolution liquid chromatography - diode array detector - ion trap mass spectrometry (RRLC-DAD-IT-MS) in this work, and a total number of 187 compounds were detected. Systematic diagnostic ion filtering strategies were recommended for flavonoids and oleanane-type triterpenoids, respectively. On the basis of the summarized strategies, compounds in Glycyrrhizae could be easily classified into flavones, isoflavones, flavanones or chalcones with special structures, and triterpene saponins with different sugar moieties. Consequently, among 187 compounds, 144 ones were confirmed or assumed tentatively. In addition, nine potential novel compounds were reported for the first time. This approach provided a rapid method for characterizing the constituents in Gui-Zhi-Tang, and would be also helpful in other TCM formulae analysis.