Visualization of the Molecular Properties Using Phenolphthalein Derivatives

在过去的两年中，我们研究了三种类型的客体特性的视觉识别，使用宿主化合物，酚酞和两种冠醚的杂化分子。(i)非保护二肽的序列选择性视觉识别；宿主分子在含有赖氨酸作为c -末端的特定氨基酸序列的二肽的存在下，具有形成鲜艳紫色的能力。这种显色方法可以扩展到特定序列n端寡肽的检测，如scylliorhiin I和APP_<770>(394-410)。（二）钠、钾离子变温可视化读出系统的构建；我们发现了第一个钠离子和钾离子表现相反行为的人工识别系统。因此，随着温度的降低，宿主与NaOH络合物在566 nm附近的吸光度增加。相比之下，随着温度的降低，宿主和KOR之间的显色性降低。这些现象是由宿主分子、有色复合体和无色复合体之间的平衡引起的。（iii） β-氨基醇的视觉对映体识别；我们开发了一种以酚酞为基础的苯基取代冠醚宿主。宿主分子具有通过肉眼可检测的颜色变化来区分β-氨基醇手性的能力。我们确实观察到这种宿主分子的显色强度，而(S)或(R)-客体在转化温度下被逆转。

During the past two years, we have investigated three types of visual recognition of guest properties using host compounds, hybrid molecules of phenolphthalein and two crownethers. (i)Sequence-Selective Visual Recognition of Nonprotected Dipeptides; A host molecule has an ability for developing brilliant purple color in the presence of dipeptides with a specific amino acid-sequence containing lysine as a C-terminal. This type of color development could be extended to the detection of oligopeptides of a specific sequence at the N-terminal such as scyliorhiin I and APP_<770>(394-410). (ii)Construction of a Variable Temperature Visual Read-Out System for Sodium and Potassium Ions; We have found the first artificial recognition system in which sodium and potassium ions show opposite behaviors. Thus, the absorbance at around 566 nm by the complex of host and NaOH increased as the temperature decreased. In contrast, color development between host and KOR decreased as the temperature decreased. These phenomena were caused by an equilibrium among the host molecule, a colored complex, and a colorless complex. (iii)Visual Enantiomeric Recognition of β-Amino Alcohols; we have developed a phenolphthalein based phenyl groups substituted crown ethers host. The host molecule has an ability to discriminate chirality of β-amino alcohols by naked-eye detectable color change. We really observed strength of color development of this host molecule and (S)-or (R)-guest was reversed at inversion temperature.