title: First report of non-coloured flavonoids in Echium plantagineum bee pollen: differentiation of isomers by liquid chromatography/ion trap mass spectrometry.
abstract: Apicultural products have been widely used in diet complements as well as in phytotherapy. Bee pollen from Echium plantagineum was analysed by high-performance liquid chromatography/photodiode-array detection coupled to ion trap mass spectrometry (HPLC-PAD-MS(n)) with an electrospray ionisation interface. The structures have been determined by the study of the ion mass fragmentation, which characterises the interglycosidic linkage in glycosylated flavonoids and differentiates positional isomers. Twelve non-coloured flavonoids were characterised, being kaempferol-3-O-neohesperidoside the major compound, besides others in trace amounts. These include quercetin, kaempferol and isorhamnetin glycosides, with several of them being isomers. Acetylated derivatives are also described. This is the first time that non-coloured flavonoids are reported from this pollen, with MS fragmentation proving to be most useful in the elucidation of isomeric structures.
authors.affiliation: Research Group on Quality, Safety and Bioactivity of Plant Foods, Department of Food Science and Technology, CEBAS (CSIC), P.O. Box 164, 30100 Campus University Espinardo (Murcia), Spain. federico@cebas.csic.es
authors.forename: Federico
authors.initials: F
authors.lastname: Ferreres
authors.forename: David M
authors.initials: DM
authors.lastname: Pereira
authors.forename: Patrícia
authors.initials: P
authors.lastname: Valentão
authors.forename: Paula B
authors.initials: PB
authors.lastname: Andrade
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003116:Color; D036661:Echium / Q000737:chemistry* / Q000378:metabolism; D005419:Flavonoids / Q000737:chemistry* / Q000378:metabolism; D007536:Isomerism; D013058:Mass Spectrometry / Q000379:methods*; D011058:Pollen / Q000737:chemistry* / Q000378:metabolism
chemical_list: D005419:Flavonoids