金合欢素-7-O-葡萄糖苷与BSA相互作用的荧光光谱法研究

应用荧光光谱法研究了生理条件下金合欢素-7-O-葡萄糖苷与牛血清白蛋白（BSA）的相互作用。结果表明,其对BSA荧光的猝灭机制属于形成复合物的静态猝灭过程,并求得结合常数Ka为8.57×104L.mol-1,结合位点数n为1。根据热力学参数确定了其与BSA之间的主要作用力类型为静电作用力。采用同步荧光考察了药物对BSA构象的影响。此外,讨论了共存离子Cu2＋,Al3＋,Zn2＋,Mg2＋对药物与BSA结合作用的影响。

Study on the interaction between flavonoid components of Dracocephalum moldavica and bovine serum albumin by fluorescence spectroscopy

The interaction of acacetin-7-O-glucose and bovine serum albumin （BSA） under physiological condition was studied by fluorospectrophotometry.The experiment demonstrated that the fluorescence quenching of BSA by acacetin-7-O-glucose is a result of the formation of pharmaceutical-BSA complex and the quenching mechanism is mainly static quenching.The apparent binding constants（Ka） between acacetin-7-O-glucose and BSA were 8.57×104L·mol-1,and the binding sites（n） were 1.According to the binding constants of the different temperatures,the thermodynamic parameters ΔH,ΔG,ΔS were calculated.From thermodynamic parameters it can be judged that the binding force between pharmaceutic and BSA is mainly electrostatic force.The effect of acacetin-7-O-glucose on the conformation of BSA was analyzed by synchronous fluorescence spectrometry.In addition,in the plasma,there are some metal ions,which can participate in many important vital actions and affect the reactions of the drugs with the serum albumins.So the effect of Cu（Ⅱ）,Al（Ⅲ）,Zn（Ⅱ）and Mg（Ⅱ） on the binding constant of acacetin7-O-glucose to BSA was also discussed.