Targeted Offline Two-Dimensional HPLC and UHPLC-Orbitrap-MS Combined with Molecular Networking Reveal the Effect of Processing on Chemical Constituents of Xuetong (the Stem of Kadsura heteroclita)

Xuetong, the dried stem of Kadsura heteroclita (Roxb.) Craib, is a traditional Tujia medicine extensively used to treat rheumatoid arthritis (RA). All traditional Chinese medicines (TCMs) necessitate a processing stage called “Paozhi” before clinical application. However, there is a dearth of research concerning the processing methods employed for Xuetong. To investigate the impact of vinegar and wine processing on the chemical constituents of Xuetong, this study devised a targeted offline two-dimensional (2D) high-performance liquid chromatography (HPLC) and ultra-high-performance liquid chromatography-orbitrap mass spectrometry (UHPLC-orbitrap-MS) method. By incorporating various MS data-processing techniques, such as molecular networking technology, fragment-ion similarity searching (FISh), online and offline database matching, and fragmentation pattern analysis, a total of 158 components were identified in Xuetong. Among them, 14 were verified by comparison with the reference standards. Notably, aside from triterpenoids and lignans, catechin derivatives were found to be the predominant constituents of Xuetong, and their levels exhibited a significant decrease following processing. This method significantly improved peak capacity and resolution, overcoming the limitations of 1D LC in simultaneously analyzing highly polar catechin derivatives and less polar triterpenoids and lignans. Moreover, the developed method shows promise for Xuetong’s quality control.