†Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
‡Laboratory for Integrated Biodevice Unit, Quantitative Biology Center, RIKEN, Chuo-ku, Kobe, Hyogo 650-0047, Japan.
Anal Chem. 2015;87(10):5068-73. doi: 10.1021/acs.analchem.5b00998. Epub 2015 May 6.
An effective separation and detection procedure for sugars by capillary electrophoresis (CE) using a complexation between quinolineboronic acid (QBA) and multiple hydroxyl structure of sugar alcohol is reported. We investigated the variation of fluorescence spectra of a variety of QBAs with sorbitol at a wide range of pH conditions and then found that 5-isoQBA strongly enhanced the fluorescence intensity by the complexation at basic pH conditions. The other sugar alcohols having multiple hydroxyls also revealed the enhancement of the fluorescence intensity with 5-isoQBA, whereas the alternation of the intensity was not found in the sugars such as glucose. After optimization of the 5-isoQBA concentration and pH of the buffered solution in CE analysis, 6 sugar alcohols were successfully separated in the order based on the formation constants with 5-isoQBA, which were calculated from the variation of the fluorescence intensity with each sugar alcohol and 5-isoQBA. Furthermore, the limits of detection for sorbitol and xylitol by the CE method were estimated at 15 and 27 μM, respectively.
本文报道了一种利用喹啉硼酸（QBA）与糖醇的多个羟基结构之间的络合作用，通过毛细管电泳（CE）有效分离和检测糖的方法。我们研究了多种 QBA 与山梨糖醇在宽 pH 条件下荧光光谱的变化，然后发现 5-异喹啉硼酸在碱性 pH 条件下通过络合强烈增强了荧光强度。其他具有多个羟基的糖醇也显示出与 5-异喹啉硼酸的荧光强度增强，而在葡萄糖等糖中则没有发现强度的变化。在 CE 分析中优化了 5-异喹啉硼酸浓度和缓冲溶液的 pH 值后，根据与 5-异喹啉硼酸形成常数的变化，成功地按与 5-异喹啉硼酸形成常数的顺序分离了 6 种糖醇，这些常数是根据每种糖醇和 5-异喹啉硼酸的荧光强度变化计算得出的。此外，通过 CE 法测定山梨糖醇和木糖醇的检出限分别为 15 和 27 μM。
