Structural Relationship and Binding Mechanisms of Five Flavonoids with Bovine Serum Albumin

Molecules

E-Hu Liu¹  Lian-Wen Qi¹ 

[1] ¹Key Laboratory of Modern Chinese Medicines (China Pharmaceutical University), Ministry of Education, Nanjing 210009, China ²Department of Pharmacognosy, College of Pharmacy, 3rd Military Medical University, Chongqing, China

关键词: flavonoids;    bovine serum albumin;    fluorescence quenching;    binding mechanism;   

DOI  :  10.3390/molecules15129092

来源: mdpi

【 摘 要 】

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 > rutin > calycosin > calycosin-7-O-β-D-glucoside ≈ formononetin-7-O-β-D-glucoside. The results of thermodynamic parameters ΔG, ΔH, and ΔS at different temperatures indicated that the hydrophobic interaction played a major role in flavonoid-BSA association. The distance r between BSA and acceptor flavonoids was also obtained according to Förster’s theory of non-radiative energy transfer.

【 授权许可】

CC BY   
This is an open access article distributed under the Creative Commons Attribution License (CC BY) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.