Rapid Characterization and Identification of the Chemical Constituents in San-Huang-Xie-Xin-Tang, a Traditional Chinese Medicine Formula, by High Performance Liquid Chromatography Coupled to Electrospray Ionization and Quadrupole Time-of-Flight Mass

San-Huang-Xie-Xin-Tang (SHXXT), a traditional Chinese medicine formula composed of Coptidis rhizome (CR), Scutellariae radix (SR) and Rhei rhizome (RR), is widely used to treat hypertension, gastritis and peptic ulcer clinically. However, the chemical constituent of SHXXT is still unclear due to its complexity, which hindered the discovery of effective compounds and quality control. Thus, an in-depth understanding of its chemical constituents is very essential. To address this problem, comprehensive analysis of chemical constituents of SHXXT was performed by high performance liquid chromatography coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS/MS). As a result, 45 compounds were identified, including 8 phenolic acids, 15 flavonoids, 13 alkaloids, 8 anthraquinones and 1 lignan. Among them, 17 compounds were from CR, 17 compounds were from SR and 11 compounds were from RR. This established method can systematically and rapidly analyze the chemical constituents in SHXXT, which provides chemical foundation for further research on effective substances and action mechanism of SHXXT.