Rapid Identification of Chemical Compounds in Danzhi Jiangtang Capsule Using Ultra‐Performance Liquid Chromatography Quadrupole Time‐of‐Flight Mass Spectrometry Combined With Multiple Data Processing Techniques

ABSTRACT Danzhi Jiangtang capsule (DJC) is a traditional Chinese medicine prescription that has been clinically used to treat Type 2 diabetes mellitus and its complications. However, research on the chemical compounds present in DJC remains limited. In this study, an analytical strategy based on ultra‐performance liquid chromatography quadrupole time‐of‐flight mass spectrometry (UPLC‐Q‐TOF/MS) was developed for the rapid and systematic characterization of chemical compounds in DJC. Firstly, a DJC self‐built database was established, and UPLC‐Q‐TOF/MS was applied for comprehensive profiling of DJC's chemical compounds. Then, R language combined with MZmine was used for data preprocessing to construct the ion information list and extract effective data. Finally, the compounds were identified by multiple data processing techniques (multiple‐point screening mass defect filtering [MDF], extracted ion chromatogram [EIC], neutral loss filter [NLF], diagnostic fragment ion filtering [DFIF], and direct identification method [including retention time, fragment behavior and reference substances]). Eventually, 137 compounds were characterized from DJC, including 19 monoterpenoids, 26 triterpenoids, 8 flavonoids, 12 iridoids, 7 phenylethanoid glycosides, 8 acetophenones, 23 organic acids, 2 violet ketones, 13 cyclic peptides, 8 alkaloids, 2 fatty acids, and 9 other compounds. Among these, 16 compounds were verified using reference substances. The study indicated that the analytical strategy established in this study effectively supports the in‐depth study of DJC's chemical constituents and provides essential data for subsequent in vivo studies.