荧光法研究左氧氟沙星与人血清白蛋白作用机理及含量测定

Study on the Interaction between Levofloxacin and Human Serum Albumin by Fluorescence and Determination

利用荧光及紫外光谱法研究了水溶液体系中左氧氟沙星(LVFX)与人血清白蛋白(HSA)的相互作用机制。结果表明左氧氟沙星对人血清白蛋白的荧光有较强的猝灭作用,其猝灭类型主要为静态猝灭。在不同温度下求得了左氧氟沙星与人血清白蛋白的结合常数k,发现随反应温度上升k值下降。由热力学参数,确定了左氧氟沙星与人血清白蛋白的结合作用主要为色散力。用同步荧光技术考察了左氧氟沙星对人血清白蛋白构象的影响,又根据Foerster理论,测得了左氧氟沙星与人血清白蛋白结合的能量转移效率,相互结合距离。进一步证明了该反应是单一静态猝灭过程,阐述了其猝灭机理是通过能量转移产生的。研究发现人血清白蛋白荧光猝灭程度的对数与左氧氟沙星含量有良好的线性关系,25℃时线性范围为:2.0×10-6—2.4×10-5mol·L-1,检出限为1.2×10-7mol·L-1。用于片剂中左氧氟沙星含量的测定结果满意,相对标准偏差为:1.5%—2.1%,回收率为:94.8%—97.7%。

The interaction of antibiotic drug： levofloxacin with human serum albumin （HSA）was studied by fluorescence spectroscopy and ultra-violet spectroscopy, the quenching interaction quilibrium constant K was caculated at different temperature, which is decreased with the temperature. Depending on the thermodynamic parameters,the main interaction between levofloxacin and HSA is dispersion force. Based on the mechanism of the Foerster energy transference.the transfer efficiency of energy and distance between the acceptor levofloxacin and HSA were found. The course of action is single static quenching and the mechanism of quenching was based on energy transfer. The good linear relationship between the degree of BSA quenching and the concentration of lomefloxacin. The range of the system at 25℃ is 2.0×10^-6 - 2.4×10^-5mol·L^-1. The detection limit is 1.2×10^-7mol·L^-1. This method has been applied to the determination of lomefloxacm in pieces, the relative standard deviation is 1.5%-2. 1% ,the recovery is 94.8%- 97.7%.