HPLC-Q-TOF-MS/MS for analysis of major chemical constituents of Yinchen-Zhizi herb pair extract.

The Yinchen-Zhizi herb pair (YZHP) consists of Herba Artemisiae Scopariae (Yinchen in Chinese) and Fructus Gardeniae (Zhizi in Chinese), and is mainly used to treat icteric hepatitis, itching skin and eczema. However, the bioactive constituents responsible for the pharmacological effects of YZHP are still unclear to date. In this work, a rapid and sensitive method was established to comprehensively study the constituents in YZHP extract by HPLC-Q-TOF MS/MS. The analysis was performed on an HPLC system equipped with an Agilent poroshell 120 EC-C18 column (100 × 2.1 mm, 2.7 mm) working in a gradient elution program coupled to quadrupole-time-of-flight mass spectrometry operating in the negative ion mode. As a result, a total of 46 compounds including 17 from Herba Artemisiae Scopariae and 36 from Fructus Gardeniae were detected and tentatively identified in YZHP extract by comparing the retention time and mass spectrometry and retrieving the reference literature. More importantly, a series of constituents, such as many iridoid glycosides, were reported for the first time in this formula. The HPLC-Q-TOF MS/MS method was developed and utilized successfully to identify the major constituents in YZHP extract and would be helpful for further metabolism and pharmacology research on YZHP.