牛蒡苷-HSA体系的荧光增强效应研究

Studies on the Effect of Fluorescence Enhancement of Arctiin-HSA System

运用荧光光谱法和紫外-可见光谱法研究了牛蒡苷与人血清白蛋白(HSA)体系的荧光增强效应。结果显示,随着牛蒡苷浓度的增大,HSA的荧光强度明显增强并且发生蓝移;逐渐增大的各向异性值表明牛蒡苷能够与HSA发生键合;求得25、32和39℃时牛蒡苷与HSA反应的结合常数分别为1.04×105、9.78×104和9.58×104L.mol-1;热力学参数(ΔH=-4.63 kJ.mol-1,ΔS=80.48 J.mol-1.K-1)表明维持药物与蛋白质的相互作用力主要是静电作用力。

The effect of fluorescence enhancement between arctiin and human serum albumin （HSA） was investigated by fluorescence and UV/vis absorption spectra under the simulated physiological conditions. The experimental results showed that the fluorescence intensity of HSA could be highly enhanced accompanied with blue shift by the addition of arctiin. The fluorescence anisotropy （r） of arctiin was increased when HSA was added, which suggested that arctiin could combine with HSA. The binding constants at 298 K, 305 K and 312 K were calculated to be 1.04×10^5, 9.78×10^4 and 9.58×10^4 L·mol^-1 , respectively. The thermodynamic parameters obtained （△H：- 4.63 kJ·mol^-1, △S：80.48 J·mol^-1. K^-1） implied that electrostatic interaction should be the predominant intermolecular forces stabilizing the complex.