In-Depth Exploration of Chemical Constituents from Justicia procumbens L. Through UHPLC-Q-Exactive Orbitrap Mass Spectrometry

<i>Justicia procumbens</i> L. (JP) has been traditionally used to treat colds with fever, swollen and sore throat, jaundice, malaria and eczema. Studies indicate that lignans constitute the primary bioactive components, yet systematic phytochemical investigations remain limited. Therefore, it is necessary to establish a rapid and effective method to identify the chemical components in JP. In this study, ultra-high-performance liquid chromatography-quadrupole-Exactive Orbitrap mass spectrometry (UHPLC-Q-Exactive Orbitrap MS) coupled with parallel reaction monitoring (PRM) was used for the first time to investigate JP. Based on chromatographic retention times, MS and MS² data, and bibliography data, a total of 132 compounds were tentatively identified, including 54 lignans, 19 flavonoids, 31 organic acids, 18 alkaloids, and 10 other types of constituents. Among these, 77 compounds are reported for the first time in JP, including 14 potential novel compounds. These results provide valuable reference and data support for the study of pharmacodynamic substances and quality control of this medicinal plant.