Determination of metabolites of phloretin in rats using UHPLC-LTQ-Orbitrap mass spectrometry

Abstract

Purpose: To study the metabolites of phloretin in vivo using ultra-high performance liquid chromatography linear ion trap-Orbitrap mass spectrometry (UHPLC-LTQ-Orbitrap). Methods: After administration of phloretin (50 mg/kg; oral route) to six rats, blood samples were taken from each animal. Each sample was then subjected to solid-phase extraction to prepare it for chromatographic/spectroscopic analysis. Finally, each sample was analyzed using UHPLC-LTQOrbitrap with a negative-mode electrospray ionization source. Results: Based on mass measurements, chromatographic retention times, and MS2 fragmentation ions, we detected and identified phloretin and 16 metabolites of the drug in vivo in rats. Metabolic reactions of phloretin included glucosylation and glucuronide conjugation, diglucuronide conjugation, glucosylation and sulfate conjugation, sulfate conjugation, glucuronide conjugation, and glucosylation and hydroxylation. Conclusion: The findings provide a better understanding of phloretin metabolism and metabolites, and new information about their effective forms, pharmacological actions, metabolic fate, and toxic actions in vivo.