Ultra-high performance liquid chromatography coupled with time-of-flight mass spectrometry screening and analysis of potential bioactive compounds from traditional chinese medicine Kai-Xin-San, using a multivariate data processing approach and the MetaboLynx tool

Traditional Chinese Medicine (TCM) has been used in clinical practice for several thousand years, with an indispensable role in prevention and treatment of disease using multiple ingredients. Kai-Xin-San (KXS) is a TCM formula consisting of four herbs, Ginseng Radix, Polygalae Radix, Poria and Acori Tatarinowii Rhizoma, which has been used to treat Alzheimer's disease, depression and Parkinson's disease. However, the constituents absorbed into blood after oral administration of KXS remain unknown. Here, a sensitive and rapid method using ultra performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS/MS) combined with a multivariate data processing approach (Mdpa) and MetaboLynx software tool was used for analysis and identification of bioactive components and their metabolites in rat plasma following oral administration of KXS. A hyphenated MS/MS analyzer was used for determination of accurate fragment ions and mass spectrometric fragmentation mechanisms, and enhanced data acquisition. Metabolite elucidation was performed using UPLC/Q-TOF-MS/MS coupled with MetaboLynx tool. With the established method, a total of 49 peaks were tentatively characterized in vivo based on MS and MS/MS data, and comparison with available databases. Of the 49 compounds tentatively characterized in rat plasma, seven metabolites were detected and identified by comparing their fragmentation patterns using MetaboLynx software tool. On the basis of the chromatographic peak area, the glucuronidated conjugates were identified as major metabolites. This work demonstrated the potential of the UPLC/Q-TOF-MS/MS with Mdpa and MetaboLynx for rapid, simple, reliable and automated identification of metabolites of herbal medicine.