title: Synthesis and properties of umbelliferone-nitroxide radical hybrid compounds as fluorescence and spin-label probes.
abstract: Two hybrid compounds 6 and 7, linked via an ester-bond between the 7-hydroxyl residue of an umbelliferone 1 and a carboxylic acid residue of two nitroxide radicals 3 and 4, and one hybrid compound 8, linked via an ester-bond between a 3-carboxylic acid residue of umbelliferone 2 and a hydroxyl residue of nitroxide radical 5, were synthesized in good yields, and their fluorescence and ESR spectra before and after the addition of L-ascorbic acid sodium salt in PBS (pH 7.0) were measured. The ESR intensities of 6 and 7 were proportionally reduced after the addition of ascorbic acid sodium salt, and their fluorescence intensities were increased maximally by eight- and nine-fold, respectively. However, the fluorescence intensity of 8 was essentially unchanged.
authors.affiliation: Department of Chemistry and Chemical Engineering, Faculty of Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa-shi, Yamagata 992-8510, Japan. shingo-s@yz.yamagata-u.ac.jp
authors.forename: Shingo
authors.initials: S
authors.lastname: Sato
authors.forename: Minoru
authors.initials: M
authors.lastname: Suzuki
authors.forename: Tomoki
authors.initials: T
authors.lastname: Soma
authors.forename: Minoru
authors.initials: M
authors.lastname: Tsunoda
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D005453:Fluorescence; D005609:Free Radicals / Q000032:analysis / Q000138:chemical synthesis / Q000737:chemistry*; D015394:Molecular Structure; D009589:Nitrogen Oxides / Q000032:analysis* / Q000138:chemical synthesis* / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013113:Spin Labels / Q000138:chemical synthesis*; D014468:Umbelliferones / Q000737:chemistry*
chemical_list: D005609:Free Radicals; D009589:Nitrogen Oxides; D013113:Spin Labels; D014468:Umbelliferones; C039900:nitroxyl