title: Determination of interglycosidic linkages in O-glycosyl flavones by high-performance liquid chromatography/photodiode-array detection coupled to electrospray ionization ion trap mass spectrometry. Its application to Tetragonula carbonaria honey from Australia.
abstract: BACKGROUND
  Tetragonula carbonaria pot-honeys are highly valued as a food source and for their biological activities in Australia, and there is a growing interest to know its composition. Phenolic metabolites, which could be related to their beneficial properties, have not been studied in depth yet.
  
  
  METHODS
  Mass spectrometry (MS) coupled to liquid chromatography (LC) is an advanced technique for the study of complex flavonoids present in difficult food matrices that hampers their isolation and purification. This allows the tentative characterization of diglycosides/triglycosides establishing the position of the O-glycosylation on the sugar moiety by the study of the MS data in T. carbonaria pot-honeys from Australia.
  
  
  RESULTS
  Their spectra obtained by high-performance liquid chromatography/photodiode-array detection/electrospray ionization ion trap mass spectrometry (HPLC/DAD/ESI-MS(n) ) revealed for the first time 19 quercetin, kaempferol and isorhamnetin O-glycosides. These compounds were clustered in flavonoid triglycosides, diglycosides and monoglycosides. The first cluster contained one flavonoid trihexoside, two -3-O-(2-hexosyl, 6-rhamnosyl)hexosides and their isomers and two -3-O-(2,6-di-rhamnosyl)hexosides. In the second cluster, eleven flavonoid diglycosides such as three -3-O-(2-hexosyl)hexosides, four -3-O-(2-rhamnosyl)hexosides and one -3-O-(6-rhamnosyl)hexoside as well as two -3-O-(2-pentosyl)hexosides and one tentative -3-O-(3-pentosyl)hexoside were detected. In the monoglycoside group, only one flavonoid -3-O-hexoside was identified.
  
  
  CONCLUSIONS
  The occurrence of this large number of flavonoid glycosides could be due to the low glucosidase activity previously reported in stingless bee honey.
authors.affiliation: Research Group on Quality, Safety and Bioactivity of Plant Foods, CEBAS-CSIC, P.O. Box 164, Espinardo, 30100, Murcia, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Truchado
authors.affiliation: Universidad Técnica de Machala, Provincia El Oro, Ecuador.|Faculty of Pharmacy, Universidad de Los Andes, Mérida, Venezuela.|University of Sydney, Lidcombe, NSW, Australia.
authors.forename: Patricia
authors.initials: P
authors.lastname: Vit
authors.affiliation: CSIRO Entomology, Long Pocket Lab, Indooroopilly, Queensland, Australia.
authors.forename: Tim A
authors.initials: TA
authors.lastname: Heard
authors.affiliation: Research Group on Quality, Safety and Bioactivity of Plant Foods, CEBAS-CSIC, P.O. Box 164, Espinardo, 30100, Murcia, Spain.
authors.forename: Francisco A
authors.initials: FA
authors.lastname: Tomás-Barberán
authors.affiliation: Research Group on Quality, Safety and Bioactivity of Plant Foods, CEBAS-CSIC, P.O. Box 164, Espinardo, 30100, Murcia, Spain.
authors.forename: Federico
authors.initials: F
authors.lastname: Ferreres
mesh_terms: D000818:Animals; D001516:Bees / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D047309:Flavones / Q000032:analysis*; D006027:Glycosides / Q000032:analysis*; D006722:Honey / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods
chemical_list: D047309:Flavones; D006027:Glycosides