State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, PR China.
Spectrochim Acta A Mol Biomol Spectrosc. 2011 May;78(5):1553-9. doi: 10.1016/j.saa.2011.01.049. Epub 2011 Feb 2.
The supramolecular interaction of MAH-β-cyclodextrin (MAH-β-CD, a modified β-cyclodextrin carrying seven vinyl carboxylic acid groups) and meferamic acid (MF) has been studied by spectrofluorimetry. The results showed that MAH-β-CD reacted with MF to form a host-guest complex (MAH-β-CD-MF) with stoichiometry (1:1) and the inclusion constant (K=7.15×10(2) L/mol) was ascertained by the typical double reciprocal plots. From the phase-solubility diagram, an increase in the water solubility of the drug was observed and the apparent stability constant (K(1:1)) was calculated to be 8.62×10(2) L/mol. Furthermore, the thermodynamic parameters (ΔG°, ΔH° and ΔS°) of MAH-β-CD-MF were obtained and the inclusion mechanism was also preliminarily discussed. In order to further confirm the experimental results, investigation on the molecular modeling was performed. On the basis of the significant enhancement of the fluorescence intensity of MF, a spectrofluorimetric method for MF determination in bulk aqueous solution in the presence of MAH-β-CD was developed. The linear range was 2.00×10(-8)-9.00×10(-5) mol/L and the detection limit was 3.36×10(-9) mol/L. The proposed method was successfully applied to determine MF in tablets, serum and urine with the satisfactory result.
MAH-β-环糊精（MAH-β-CD，一种带有七个乙烯羧酸基团的改性β-环糊精）与美非拉酸（MF）的超分子相互作用已通过荧光光谱法进行了研究。结果表明，MAH-β-CD 与 MF 反应形成了主客体配合物（MAH-β-CD-MF），其化学计量比为 1:1，通过典型的双倒数图确定了包含常数（K=7.15×10² L/mol）。从相溶解度图中观察到药物的水溶性增加，并计算出表观稳定常数（K（1:1））为 8.62×10² L/mol。此外，还获得了 MAH-β-CD-MF 的热力学参数（ΔG°、ΔH°和ΔS°），并初步讨论了包含机制。为了进一步证实实验结果，还进行了分子建模研究。基于 MF 荧光强度的显著增强，建立了在 MAH-β-CD 存在下测定 bulk 水溶液中 MF 的荧光光谱法。线性范围为 2.00×10⁻⁸-9.00×10⁻⁵ mol/L，检测限为 3.36×10⁻⁹ mol/L。该方法成功应用于片剂、血清和尿液中 MF 的测定，结果令人满意。
