structural relationship and binding mechanisms of five flavonoids with bovine serum albumin结构关系和绑定机制五个黄酮类化合物与牛血清白蛋白.pdfVIP

Molecules 2010, 15, 9092-9103; doi:10.3390/molecule OPEN ACCESS molecules ISSN 1420-3049 /journal/molecules Article Structural Relationship and Binding Mechanisms of Five Flavonoids with Bovine Serum Albumin E-Hu Liu 1,2, Lian-Wen Qi 1 and Ping Li 1,* 1 Key Laboratory of Modern Chinese Medicines (China Pharmaceutical University), Ministry of Education, Nanjing 210009, China 2 Department of Pharmacognosy, College of Pharmacy, 3rd Military Medical University, Chongqing, China * Author to whom correspondence should be addressed; E-Mail: liping2004@126.com; Tel./Fax: +86-25-8327 1379. Received: 9 October 2010; in revised form: 1 December 2010 / Accepted: 6 December 2010 / Published: 9 December 2010 Abstract: Flavonoids are structurally diverse and the most ubiquitous groups of dietary polyphenols distributed in various fruits and vegetables. In this study, the interaction between five flavonoids, namely formononetin-7-O-β-D-glucoside, calycosin- 7-O-β-D-glucoside, calycosin, rutin, and quercetin, and bovine serum albumin (BSA) was investigated by fluorescence and UV-vis absorbance spectroscopy. In the discussion, it was proved that the fluorescence quenching of BSA by flavonoids was a result of the formation of a flavonoid-BSA complex. Fluorescence quenching constants were determined using the Stern-Volmer and Lineweaver-Burk equations to provide a measure of the binding affinity between the flavonoids and BSA. The binding constants ranked in the order quercetin rut