LAUSR

BACKGROUND Schizonepetae Herba (SH, Jingjie) and Schizonepetae Herba Carbonisata (SHC, Jingjie Tan) are two different forms of the same herbal material, with SHC being the processed product of SH. The different clinical efficacies of SH and SHC may be caused by changes in their chemical compositions. Despite this, there have been few studies that have reported on the comparative identification of SH and SHC. Therefore, the aims of this experiment are to investigate the differential changes of non-volatile and volatile components before and after SH processing. OBJECTIVES To establish combination strategies for identifying the chemical markers in SH and SHC, ultra-high-performance liquid chromatography quadrupole time of flight mass spectrometry (UHPLC-Q-TOF-MS) and headspace gas chromatography mass spectrometry (HS-GC-MS) to use. METHODS An untargeted metabolomics approach using UHPLC-Q-TOF-MS and HS-GC-MS was utilized to comprehensively discriminate between SH and SHC. To identify chemical markers, principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were performed on 14 batches of SH and SHC. RESULTS A total of 71 non-volatile compounds and 81 volatile compounds were tentatively identified in SH and SHC. Among these, 14 non-volatile compounds and 18 volatile oils were found to be potential characteristic markers that can differentiate between SH and SHC. CONCLUSIONS The present work provides valuable information for understanding the chemical differences between SH and SHC. The results obtained from this research may serve as a scientific foundation for comprehensively revealing the mechanisms involved in the carbonizing processing method of stir-frying SH. HIGHLIGHTS The chemical changes that occur before and after carbonizing Schizonepetae Herba were investigated using integrated methods based on LC-MS and GC-MS, and chemical markers in SH and SHC were identified.