Zhou Yunyou, Xu Hongwei, Yu Huapeng, Chun Liu, Lu Qin, Wang Lun
Anhui Key Laboratory of Functional Molecular Solids, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2008 Jul;70(2):411-5. doi: 10.1016/j.saa.2007.10.055. Epub 2007 Nov 29.
Spectrofluorometric titrations have been performed to investigate the inclusion behavior of p-(p-carboxyl benzeneazo) calix[4]arene (CBC4A) with norfloxacin (NFLX) in NaAc-HAc buffer solution (pH=5.0). It was found that the fluorescence intensity of NFLX quenched regularly upon the addition of CBC4A. The results indicated 1:1 complex stoichiometry and an association constant of 8.21 x 10(5) L mol(-1) at 20.0 degrees C were calculated by applying a deduced equation. Job's plot also verified the existence of 1:1 inclusion complex. The proposed interaction mechanism indicates that NFLX goes into (or partially goes into) the cavity of CBC4A with the help of hydrogen bonding and other forces. The various factors (pH value, ionic strength, and surfactants) affecting the inclusion process were examined in details.
在NaAc-HAc缓冲溶液(pH = 5.0)中进行了荧光光谱滴定,以研究对(对羧基苯偶氮)杯[4]芳烃(CBC4A)与诺氟沙星(NFLX)的包合行为。结果发现,加入CBC4A后,NFLX的荧光强度有规律地猝灭。结果表明形成了1:1的配合物化学计量比,通过推导方程计算得出在20.0℃时缔合常数为8.21×10⁵ L·mol⁻¹。Job曲线也证实了1:1包合配合物的存在。提出的相互作用机制表明,NFLX在氢键和其他作用力的帮助下进入(或部分进入)CBC4A的空腔。详细研究了影响包合过程的各种因素(pH值、离子强度和表面活性剂)。