Abstract: Objective To analyze the chemical constituents of Polygonum multiflorum Thunb. Leaves, observe the changes in chemical constituents steaming, and to explore the effect of steaming on the chemical constituents. Methods The Waters Acquity UPLC BEH-C₁₈ column (100 mm×2.1 mm, 1.7 μm) was used, and the mobile phase was composed of 0.1% formic acid water solution (A) - acetonitrile (B) under gradient elution. Q-Exactive-Orbitrap MS was used for data acquisition and analysis. The chemical constituents were qualitatively and relatively quantitatively analyzed by using standard products, and the results were compared with what was reported in literature. Results Thirty components were identified in Polygonum multiflorum Thunb. leaves and their steamed products. The relative contents of characteristic components changed significantly after steaming. The contents of stilbene glycosides and anthraquinones decreased, especially the former, whose content plummeted by more than 50%, while that of tannins increased. Conclusion Polygonum multiflorum Thunb. leaves contain such components as stilbene glycosides, anthraquinones and flavonoids, which are consistent with the characteristic components in the roots. The contents of components change after steaming. This study is expected to provide data for the tapping of its medicinal value and ensuring the safety of the drug for internal use.

Key words: Polygonum multiflorum Thunb. Leaves, Stilbene Glucoside, Anthraquinone, Flavone, Steaming Processing, Q-Exactive-Orbitrap MS