title: A novel method using high-performance liquid chromatography with fluorescence detection for the determination of betaxanthins.
abstract: Betaxanthins are natural water-soluble yellow pigments present in plants of the order Caryophyllales. The native fluorescence of these compounds is extensively characterized in this work, with study of the fluorescent properties of 14 different betaxanthins. All the species showed a similar behavior, with excitation maxima between 463 and 475 nm and emission maxima between 506 and 515 nm. Thus, betaxanthins absorb light corresponding to the blue color and emit visible green light. Similarities in excitation and emission spectra point to the responsibility of betalamic acid in fluorescence. The influence of the amine moiety is discussed. For the first time fluorescent properties of betaxanthins are applied to the detection of these pigments after separation by high-performance liquid chromatography. Wavelengths used were 460 nm for excitation and 510 nm for emission, which were suitable for detecting the native fluorescence of all the pigments assayed. Calibration was performed in each case and it exhibited linearity within the range considered, at least 20 microM. The lowest detection limit was 100 nM, corresponding to betaxanthins derived from methionine sulfoxide and leucine. Fluorescence detection was applied to the quantification of betaxanthins present in Carpobrotus acinaciformis. The present work opens up new possibilities for the analysis of betaxanthins by improving existing protocols through fluorescence detection.
authors: Departamento de Bioquímica y Biología Molecular A, Unidad Docente de Biología, Facultad de Veterinaria, Universidad de Murcia, E-30100 Espinardo, Murcia, Spain.
authors: Fernando
authors: F
authors: Gandía-Herrero
authors: Francisco
authors: F
authors: García-Carmona
authors: Josefa
authors: J
authors: Escribano
mesh_terms: D050859:Betacyanins; D050858:Betalains; D029748:Caryophyllaceae / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007211:Indoles / Q000302:isolation & purification; D019684:Magnoliopsida / Q000737:chemistry; D010848:Picolinic Acids / Q000737:chemistry* / Q000302:isolation & purification*; D011725:Pyridines / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D050859:Betacyanins; D007211:Indoles; D010848:Picolinic Acids; D011725:Pyridines; C488995:betaxanthin; C000252:betalamic acid; D050858:Betalains; C020228:betanin