Entrapment and Release of Guest Molecules by Reduction-Responsive Cyclophane Dimers Based on Disulfide Linkage
作者:Osamu Hayashida、Keiko Kojima
DOI:10.1246/bcsj.20140370
日期:2015.5.15
Reduction-responsive cyclophane dimer 2 having a disulfide linkage derived from an l-cystine residue was synthesized. Complex formation of 2 with anionic guests such as 6-p-toluidinonaphthalene-2-sulfonate (TNS) and 6-anilinonaphthalene-2-sulfonate (2,6-ANS) were proven by fluorescence titration experiments. The evaluated 1:1 binding constants (K) of 2 with TNS and 2,6-ANS were calculated to be 7.6 × 104 and 5.5 × 104 M−1, respectively. These binding affinities were increased 11- and 13-fold in comparison with those of a corresponding monocyclic cyclophane 3, respectively. Reduction of disulfide bond of 2 by dithiothreitol (DTT) gave the corresponding monocyclic cyclophanes having less guest-binding affinity. Consequently, such a DTT treatment promotes release of guest molecules entrapped by 2 to the bulk aqueous media.
我们合成了具有还原反应的环烷二聚体 2,该二聚体的二硫键来自于一个胱氨酸残基。 荧光滴定实验证明了 2 与 6-对甲苯胺基萘-2-磺酸盐(TNS)和 6-苯胺基萘-2-磺酸盐(2,6-ANS)等阴离子客体形成的络合物。 经计算,2 与 TNS 和 2,6-ANS 的 1:1 结合常数 (K) 分别为 7.6 × 104 和 5.5 × 104 M-1。 与相应的单环环烷 3 相比,这些结合亲和力分别提高了 11 倍和 13 倍。 用二硫苏糖醇(DTT)还原 2 的二硫键后,相应的单环环烷的客体结合亲和力降低。 因此,这种 DTT 处理会促进 2 所夹带的客体分子释放到大量水介质中。