Graduate School of Engineering, Kobe University, 1-1, Rokkoudai-cho, Nada-ku, Kobe 657-8501, Japan.
J Phys Chem B. 2012 Oct 11;116(40):12263-7. doi: 10.1021/jp307710b. Epub 2012 Oct 2.
Polyglycerol dendrimers (PGDs), which exhibit a well-defined structure consisting of only glycerol units, were examined as a host molecule of 5-fluorouracil (5-Fu) used as a model anticancer drug. (19)F- and (1)H-NMR titrations and fluorescence measurements were performed to estimate the molecular interaction between PGDs and 5-Fu in a buffer. Results of the NMR titrations revealed that PGD of generation 3 (PGD-G3) encapsulated 5-Fu in the buffer, whereas PGD-G2 and G1 partially incorporated 5-Fu molecule into the space. Fluorescent spectra of 5-Fu in the presence of PGD-G3 indicated that the diketo (lactam) form of 5-Fu changed to the enol-keto (lactim) form of 5-Fu, suggesting attraction of the imine proton of 5-Fu by ether oxygen of PGD-G3. Therefore, the encapsulation state of 5-Fu in PGDs at molecular level was modulated by the well-defined branched structure depending on the generation of PGDs.
聚甘油树枝状聚合物（PGDs）具有明确的结构，仅由甘油单元组成，被用作模型抗癌药物 5-氟尿嘧啶（5-Fu）的宿主分子进行了研究。（19）F 和（1）H-NMR 滴定和荧光测量用于估计缓冲液中 PGDs 与 5-Fu 之间的分子相互作用。NMR 滴定结果表明，第 3 代（PGD-G3）聚甘油树枝状聚合物在缓冲液中包裹 5-Fu，而第 2 代和第 1 代 PGDs 部分将 5-Fu 分子纳入空间。存在 PGD-G3 时 5-Fu 的荧光光谱表明，5-Fu 的二酮（内酰胺）形式转变为 5-Fu 的烯醇-酮（内酰胺）形式，表明 5-Fu 的亚胺质子被 PGD-G3 的醚氧吸引。因此，5-Fu 在 PGDs 中的包封状态在分子水平上取决于 PGDs 的支化结构，通过调节 PGDs 的代来进行调节。
