Identification of polyphenols and their metabolites in human urine after cranberry-syrup consumption

As the beneficial effects of American cranberry (Vaccinium macrocarpon) can be partly attributed to its phenolic composition, the evaluation of the physiological behaviour of this fraction is crucial. A rapid and sensitive method by ultra-performance liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS) has been used to identify phenolic metabolites in human urine after a single dose of cranberry syrup. Prior to the analysis, metabolites were extracted using an optimised solid-phase extraction procedure. All possible metabolites were investigated based on retention time, accurate mass data and isotope and fragmentation patterns. Free coumaroyl hexose (isomer 1 and 2), dihydroxybenzoic acid, caffeoyl glucose, dihydroferulic acid 4-O-β-d-glucuronide, methoxyquercetin 3-O-galactoside, scopoletin, myricetin and quercetin, together with other 23 phase-I and phase-II metabolites, including various isomers, could be tentatively identified in the urine. Afterwards, the metabolites were simultaneously screened in the urine of different subjects at 0, 2, 4, and 6 h after the ingestion of cranberry syrup by Target AnalysisTM software.