Rapid classification and identification of chemical constituents in Leonurus japonicus Houtt based on UPLC‐Q‐Orbitrap‐MS combined with data post‐processing techniques

Abstract Leonurus japonicus Houtt (LJH) is a bulk medicinal material commonly used in clinical practice, but its complex constituents have not been completely understood, posing challenges to pharmacology, pharmacokinetic research, and scientific and rational drug use. As a result, it is critical to develop an efficient and accurate method for classifying and identifying the chemical composition of LJH. In this study, ultra‐performance liquid chromatography‐quadrupole electrostatic field‐orbital trap high resolution mass spectrometry (UPLC‐Q‐Orbitrap‐MS) was successfully established, along with two data post‐processing techniques, characteristic fragmentations (CFs) and neutral losses (NLs), to quickly classify and identify the chemical constituents in LJH. As a result, 44 constituents of LJH were identified, including four alkaloids, 20 flavonoids, two phenylpropanoids, 17 organic acids, and one amino acid. The method in this paper enables classification and identification of chemical compositions rapidly, providing a scientific foundation for further research on the effective and toxic substances of LJH.