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性质的视觉识别使用主体化合物，混合分子的酚酞和两个冠醚。（i）未保护的二肽的序列选择性视觉识别;宿主分子在具有含有赖氨酸作为C末端的特定氨基酸序列的二肽存在下具有显现亮紫色的能力。这种显色方法可推广到N端特定序列的寡肽如Scyliorhiin I和APP_<770>（394-410）的检测。（ii）钠、钾离子变温视觉读出系统的构建我们发现了第一个钠、钾离子表现出相反行为的人工识别系统。因此，主体和NaOH的复合物在566 nm附近的吸光度随着温度降低而增加。相反，随着温度的降低，宿主与KOR之间的显色性降低。这些现象是由主体分子、有色络合物和无色络合物之间的平衡引起的。（iii）β-氨基醇的视觉对映体识别我们开发了一种基于酚酞的苯基取代冠醚主体。主体分子具有通过肉眼可检测的颜色变化来区分β-氨基醇的手性的能力。我们确实观察到这种主体分子和（S）-或（R）-客体的显色强度在反转温度下反转。

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.