槲皮素与环糊精衍生物包合物的理化性质和分子对接研究

槲皮素具有较强的抗氧化活性，对呼吸道炎症和心血管疾病具有一定疗效，在医药行业中受到广泛关注。 但是，槲皮素的水溶性和热稳定性较低，使其在医药行业的应用受到限制。环糊精（cyclodextrins，CDs）是一种 大环分子，能够与客体分子包合形成包合物，从而有效提高客体分子的溶解性、稳定性和生物利用率。本实验制备 槲皮素与β-CD、G-β-CD及G2-β-CD的包合物，利用相溶解度法研究环糊精与槲皮素的包合效果，利用紫外光谱、 傅里叶变换红外光谱、扫描电子显微镜、X射线衍射、热重及差示扫描量热技术表征槲皮素与G-β-CD包合物，借 助分子对接研究槲皮素与G-β-CD包合物的超分子结构。结果显示：槲皮素的溶解度与环糊精的浓度呈线性关系， G-β-CD与槲皮素的包合效果最好，且包合后槲皮素的热稳定性提高。分子对接结果表明槲皮素的C环嵌入G-β-CD 的空腔中形成包合物。

Characterization and Molecular Docking of Inclusion Complex of Quercetin with Modified Cyclodextrins

Quercetin is of high interest in pharmaceutical industry due to its antioxidant activity and potential therapeutic effects on airway inflammation and cardiovascular diseases. However, the application of quercetin is limited due to its low water solubility and poor stability. Cyclodextrins (CDs) are macrocyclic molecules able to form inclusion complex with guest molecules, effectively enhancing their solubility, stability and bioavailability. In order to overcome the defect of quercetin, we prepared inclusion complexes of quercetin with three different cyclodextrins such as β-CD, G-β-CD and G2-β-CD. The phase solubility study showed that there was a linear relationship between the solubility of quercetin and the molality of CDs, and G-β-CD performed the best among three cyclodextrins in terms of increasing the solubility of quercetin. In order to confirm the formation of inclusion complex, some analytical techniques were applied, such as ultravioletvisible spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy, X-ray diffraction and thermogravimetric-differential scanning calorimetry. The results revealed that the inclusion complex was formed as expected and the thermal stability of the guest molecule was improved. Furthermore, molecular docking showed that the ring C of quercetin was inserted into the hydrophobic cavity of G-β-CD during the inclusion process.