New Chrysin-based co-crystals: Synthesis, characterization and dissolution studies

Chrysin (CHY), as an important flavonoid molecule, shows various pharmacological activities. How-ever, the character of weak solubility in water restricts its pharmacology in human body. In order to further understand the interactions of O -H center dot center dot center dot N between hydroxyl groups of chrysin and various aromatic amines,and to improve the dissolution of CHY, BPY(4,4'-bipyridine) and R1(1,4-bis(pyridin-4-ylmethoxy)benzene) were assembled with CHY to form two new co-crystals (HNU-65 and 66, HNU is the abbreviation of Hainan University). Structural analysis shows that HNU-65 and 66 are formed by hydro-gen bonds and pi-pi interaction between CHY molecules with BPY/R1 molecules, respectively. Importantly, in phosphate buffer of pH = 7.4, the solubility of these two co-crystals has improved greatly. Furthermore, the two co-crystals exhibited good biological suitability by cytotoxicity assays.(c) 2022 Elsevier B.V. All rights reserved.