biostudies-literatureMeng Xthe CAMS Innovation Fund for Medical Sciencesthe Beijing Natural Science Foundation1512https://www.ebi.ac.uk/biostudies/studies/S-EPMC12736233biostudies-literatureUnknown17(12)<b>Background/Objectives</b>: Dihydroquercetin, known for its broad biological activities, is a key component in dietary supplements and functional foods. This study aims to identify its novel pure solid forms, advancing understanding of its physicochemical properties and polymorphism. <b>Methods</b>: Systematic screening, preparation, and characterization efforts identified five solvates: dihydroquercetin monohydrate (1:1, S1 and S2), sesquihydrate (1:1.5, S3), dihydrate (1:2, S4), and ACN solvate (1:1, S5), along with one solvent-free phase (S6). <b>Results</b>: The crystal structures of the five solvates were successfully elucidated for the first time. A comprehensive suite of techniques, including single-crystal and powder X-ray diffraction, DSC, TG, and FT-IR, were employed to charactPharmaceuticsX-Ray Structures, Intermolecular Interactions, and Structural Transformations of Dihydroquercetin Solvates and Polymorphs.PMC12736233No. 7222261No.2022-I2M-1-015Zou YLu YXing CGong NDu GYang SMeng XfalseX-Ray Structures, Intermolecular Interactions, and Structural Transformations of Dihydroquercetin Solvates and Polymorphs.<b>Background/Objectives</b>: Dihydroquercetin, known for its broad biological activities, is a key component in dietary supplements and functional foods. This study aims to identify its novel pure solid forms, advancing understanding of its physicochemical properties and polymorphism. <b>Methods</b>: Systematic screening, preparation, and characterization efforts identified five solvates: dihydroquercetin monohydrate (1:1, S1 and S2), sesquihydrate (1:1.5, S3), dihydrate (1:2, S4), and ACN solvate (1:1, S5), along with one solvent-free phase (S6). <b>Results</b>: The crystal structures of the five solvates were successfully elucidated for the first time. A comprehensive suite of techniques, including single-crystal and powder X-ray diffraction, DSC, TG, and FT-IR, were employed to charact2025-01-01T00:00:00Z2025 Nov2026-05-27T08:04:21.379Z2026-05-27T03:12:29.42ZS-EPMC127362334147102810.3390/pharmaceutics17121512