Abstract: Objective Analyze the chemical constituents of Rhei Radix et Rhizoma and its processed products (Raw Rhubarb Rhizome, Stew-Baked Rhubarb Rhizome, Wine-Processed Rhubarb Rhizome, Charred Rhubarb Rhizome), and initially explore the variations of content among different processed products. Methods Based on ultra-performance liquid chromatography-quadrupole-exactive orbitrap mass spectrometry (UHPLC-Q Exactive Orbitrap MS), A Hypersil GOLD aQ column (100 mm×2.1 mm, 1.9 μm) was used with mobile phases of 0.1% formic acid in acetonitrile (A) and water (B) at a 0.3 mL·min^-1 flow rate, in positive-negative ionmode. Identifica-tion and analysis of chemical constituents and relative content in Rhei Radix et Rhizoma and its processed products using self-built compound library, reference standards, and literature. Results A total of 63 chemical constituents were identified: 15 anthraquinones, 4 anthones, 13 flavonoids, 5 sugars, and 26 others. Raw Rhubarb Rhizome contains 61 constituents, Stew-Baked Rhubarb Rhizome 44, Wine-Processed Rhubarb Rhizome 54, and Charred Rhubarb Rhizome 36, with 23 constituents common to all forms. Among the shared constituents, the compounds exhibited regular differences in across the different processed products. Conclusion sProcessing Rhei Radix et Rhizoma converts bound anthraquinones into free ones, reducing its laxative effect and boosting blood-activating and hemostatic properties. Various methods affect its constituents differently; wine processing aids in extracting and preserving stable glycosides but destroys unstable ones.

Key words: Rhei Radix et Rhizoma, Processed Products, Chemical Constituents, UHPLC-Q Exactive Orbitrap MS, Anthraquinones, Flavonoids, Sugars, Anthones