Structural characterization and screening of chemical markers of alkaloids in Aconiti lateralis radix Praeparata and its processed products by UHPLC/Q-TOF-MS/MS and GNPS combining multivariate statistical methods based on the clinic.

Rational: Aconiti Lateralis Radix Praeparata (AC) is a traditional Chinese medicine with a long history of use. However, the current research on the material basis of AC and its processed products is still not comprehensive, especially the changes in lipo-diterpenoid alkaloids (LDAs) that can be hydrolyzed into diester-diterpenoid alkaloids in AC before and after processing. This study aimed to provide material basis guidance for the clinical use of AC and its processed products by comprehensively analyzing the changes in substances between AC and its processed products.

Methods: An ultra-high-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UHPLC/Q-TOF-MS/MS) approach was optimized to chemical profiling. The MS data were processed using molecular networking combined with the in-house library database to fast characterize the compounds. Multivariate statistical methods were adopted to determine the dissimilarities of components in AC and its processed products.

Results: A total of 310 compounds were tentatively identified from AC, including 109 potential new alkaloids, of which 98 were potential novel LPAs. A metabolomics approach was applied to find the characteristic marker components. As a result, 52 potential chemical markers were selected to distinguish the AC samples of different extraction methods and 42 potential chemical markers for differentiating between AC and its processed products were selected.

Conclusion: The results indicate that UHPLC/Q-TOF-MS/MS and Global Natural Products Social Molecular Networking coupled with multivariate analysis strategies was a powerful tool to rapidly identify and screen the chemical markers of alkaloids between the AC samples and its processed products. These results also indicate that the toxicity of water extracts of AC and its processed products were decreased. This research not only guides the clinical safe use of AC and its processed products, but also extends the application of the molecular networking strategy in traditional herbal medicine.