title: A fragmentation study of dihydroquercetin using triple quadrupole mass spectrometry and its application for identification of dihydroflavonols in Citrus juices.
abstract: A mass spectrometric method using electrospray ionization with triple quadrupole and quadrupole time-of-flight hybrid (Q-Tof) mass spectrometry has been applied to the structural characterization of dihydroflavonols. This family of compounds has been studied by liquid chromatography/tandem mass spectrometry (LC/MS/MS) for the first time in this work. A comprehensive study of the product ion MS spectra of the [M+H](+) ion of a commercially available standard has been performed. The most useful fragmentations in terms of structural identification are those that involve cleavage of the C-ring, resulting in diagnostic ions of dihydroflavonol family: (1,3)A(0) (+), (1,2)B(0) (+), (1,2)B(0) (+)-CO, (0,2)A(0) (+), (0,2)A(0) (+)-H(2)O, (0,2)A(0) (+)-CO, and (0,2)A(0) (+)-H(2)O-CO, that allow the characterization of the substituents in the A- and B-rings. In addition to those ions, other product ions due to losses of H(2)O and CO molecules from the Y(0) (+) ion were observed. Their fragmentation mechanisms and ion structures have been proposed. The established fragmentation patterns have been used to successfully identity three dihydroflavonols found in tangerine juices for the first time.
authors: Departamento de Química Analítica, Facultad de Ciencia y Tecnología, Universidad del País Vasco/Euskal Herriko Unibertsitatea, P.O. Box 644, 48080 Bilbao, Spain.
authors: Beatriz
authors: B
authors: Abad-García
authors: Sergio
authors: S
authors: Garmón-Lobato
authors: Luis A
authors: LA
authors: Berrueta
authors: Blanca
authors: B
authors: Gallo
authors: Francisca
authors: F
authors: Vicente
mesh_terms: D001628:Beverages / Q000032:analysis*; D002957:Citrus / Q000737:chemistry*; D044948:Flavonols / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods*; D011794:Quercetin / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: D044948:Flavonols; D011794:Quercetin; C003377:taxifolin