Studies on DNA intercalators using modified cyclodextrins

环糊精（CDs）是由至少六个葡萄糖醛酸单位组成的环状低聚糖。CD作为宿主分子被广泛研究用于分子识别和各种化合物的包封，特别是药物和药物递送系统，因为CD具有疏水腔，CD可以结合各种客体分子。为了开发对生物分子具有特异性和/或选择性亲和的改性CDs的分子识别，以及对DNA嵌入和药物递送系统的兴趣，合成了四种蒽基（烷基胺）β-CDs。通过核磁共振光谱和圆二色光谱的测量，观察了它们在客体诱导下的构象变化。通过核磁共振光谱、紫外光谱和荧光光谱的测量，观察了它们与DNA的结合能力。这种修饰的β-CDs本身不与DNA结合，但在与客体分子形成复合物后，这种复合物显示出与DNA结合的能力。它展示了一种化学开关DNA结合系统的新原理。

Cyclodextrins (CDs) are cyclic oligosaccharides consisting of at least six glucopyranose units. CDs have been extensively studied as host molecules for molecular recognition and encapsulations of various compounds, especially drugs and drug delivery systems, because CD has a hydrophobic cavity in which CD can bind various guest molecules. For development of molecular recognition using modified CDs with specific and/or selective affinities for biomolecules and also for the interest of DNA intercalation and drug delivery systems, four kinds of anthryl (alkylamino)-β-CDs were synthesized. Guest-induced conformational changes of them were observed by measurements of ^1H-NMR spectra and circular dichroism spectra. Their abilities of binding to DNA were also observed by measurements of ^1H-NMR spectra, UV spectra and fluorescence spectra. Such modified β-CDs themselves do not bind to DNA, but, after making a complex with a guest molecule, such complexes show abilities of binding to DNA.It shows a new principle of an chemically switched DNA binding system.