Detection and identification of 14C-labelled flavonol metabolites by high-performance liquid chromatography-radiocounting and tandem mass spectrometry.
One hour after the ingestion of feed containing [2-14C]quercetin-4'-O-beta-D-glucoside, an extract from the gastrointestinal tracts of three rats was purified by partitioning and solid-phase extraction techniques. The resultant ethyl acetate and aqueous fractions were then analysed by reversed-phase HPLC with on-line radioactivity detection and ion trap mass spectrometry capable of performing data dependent MS-MS analysis. The presence of the 14C-labelled metabolites was determined with the radioactivity monitor and the mass spectra produced were used to identify 16 of the 17 metabolites detected. These included methylation of the aglycone and the formation of mono and diglucuronides and sulfate conjugates. In the light of these findings, the use of mass spectrometry, operating in various modes, to identify flavonols and their metabolites in body tissues and fluids is discussed.
Mullen
William
W
Plant Products and Human Nutrition Group, Graham Kerr Building, Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
Hartley
Richard C
RC
Crozier
Alan
A
D000818:Animals; D002250:Carbon Radioisotopes; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D051381:Rats; D013056:Spectrophotometry, Ultraviolet
D002250:Carbon Radioisotopes