两种芹菜素衍生物与人血清白蛋白的相互作用

Study on the Interaction of Two Apigenin Derivatives with Human Serum Albumin

摘要:

以黄酮类化合物芹菜素（4',5,7-三羟基黄酮）为原料，利用Mannich和磺化反应先后合成了两种芹菜素衍生物Ⅰ[8-(N,N-二乙基)-亚甲基胺基-4',5,7,-三羟基黄酮]、Ⅱ[8-(N,N-二乙基)-亚甲基胺基-4',5,7,-三羟基黄酮-3'-磺酸]，并对其结构进行ESI-MS、1H-NMR、13C-NMR表征。利用荧光猝灭光谱、同步荧光光谱、紫外光谱法结合内滤光校正、分子对接研究了298、303、308 K时两种衍生物与人血清白蛋白（HSA）的相互作用机制。光谱法结果表明，衍生物Ⅰ、Ⅱ通过与HSA形成复合物而对HSA有荧光猝灭作用，猝灭原因是静态猝灭和非辐射能量转移，且衍生物与HSA的结合位点在HSA的亚结构域ⅡA附近，Ⅱ比Ⅰ更容易被转移和运输。热力学分析结果显示结合点数为1，且ΔH和ΔS均大于0，表明疏水作用为主要作用力。分子对接结果表明，两种衍生物与HSA均是通过疏水作用力和氢键结合于HSA的疏水空腔内，其中疏水作用为主要作用力，这与热力学结果相吻合。

Abstract:

Two apigenin derivatives Ⅰ[8-(N,N-diethyl)-methylene-amino-4',5,7,-trihydroxy flavone] and Ⅱ[8-(N,N-diethyl)-methylene-amino-4',5,7,-trihydroxy flavone-3'-sulfonic acid] were synthesized via Mannich and sulfonation reaction, and characterized by ESI-MS, 1H-NMR and 13C-NMR Then fluorescence quenching spectra, synchronous fluorescence spectroscopy, ultraviolet spectroscopy combined with correction of inner filter effect, along with molecular docking studies were used to investigate their interaction mechanism with human serum albumin (HSA) at 298 K, 303 K, 308 K. Spectroscopy results indicated that the intrinsic fluorescence of HSA was quenched by forming a complex with the drug. It was due to the static quenching and non-radiation energy transfer, and the binding site was near the subdomain IIA of HSA. Thermodynamic analysis showed that there was only one binding site while the interaction occurred. What’s more, ΔH > 0 and ΔS > 0 indicated that the hydrophobic force played a major role in the interaction. Docking results implied that both of the derivatives bound to the hydrophobic cavity of HSA by hydrophobic force and hydrogen bonding, wherein the hydrophobic force was the main force, which was consistent with the thermodynamic results.