Synthesis and fluorescence properties of six fluorescein-nitroxide radical hybrid-compounds
| Autor: | Tateaki Ogata, Susumu Endo, Tomohiro Ito, Masaki Yamaguchi, Yusuke Kurokawa, Shingo Sato, Akio Nagai |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
010405 organic chemistry
Hybrid compound 010402 general chemistry Ascorbic acid Photochemistry 01 natural sciences Fluorescence Nitroxide radical Atomic and Molecular Physics and Optics 0104 chemical sciences Analytical Chemistry chemistry.chemical_compound Fluorescence intensity chemistry Phenol Methanol Fluorescein Instrumentation Spectroscopy |
| Zdroj: | Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 169:66-71 |
| ISSN: | 1386-1425 |
| DOI: | 10.1016/j.saa.2016.06.021 |
| Popis: | Six fluorescein-nitroxide radical hybrid-compounds (2ab, 3ab, 4, and 5) were synthesized by the condensation of 5- or 6-carboxy-fluorescein and 4-amino-TEMPO (2ab), 5- or 6-aminofluorescein and 4-carboxy-TEMPO (3ab), and fluorescein and 4-carboxy-TEMPO (4), or by reaction of the 3-hydroxyl group of fluorescein with DPROXYL-3-ylmethyl methanesulfonate (5). Fluorescence intensities (around 520nm) after reduction of the radical increased to 1.43-, 1.38-, and 1.61-folds for 2a, 2b and 3b respectively; 3a alone exhibited a decrease in intensity on reduction. Since 4 was readily solvolyzed in PBS or even methanol to afford fluorescein and 4-carboxy-TEMPO, its fluorescence change could not be measured. Hybrid compound 5 containing an ether-linkage between the fluorescein phenol and 3-hydroxymethyl-DPROXYL hydroxyl centers, was stable and on reduction, showed a maximum increase (3.21-fold) in relative fluorescence intensity in PBS (pH5.0), despite its remarkably low absolute fluorescence intensity. |
| Databáze: | OpenAIRE |
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