title: The achievement of mass balance by simultaneous quantification of floxuridine prodrug, floxuridine, 5-fluorouracil, 5-dihydrouracil, α-fluoro-β-ureidopropionate, α-fluoro-β-alanine using LC-MS.
abstract: 5-Fluoro-2'-deoxyuridine (floxuridine, 5-FdUrd) and 5-fluorouracil (5-FU) are widely used for the treatment of colorectal cancers. The mechanisms of action of 5-FdUrd and 5-FU, as well as the biochemical pathway responsible for their metabolism, are well understood. Identification of every metabolite and achieving mass balance by conventional UV absorption-based HPLC analysis are not feasible because the metabolites beyond 5-FU in the 5-FdUrd metabolic pathway are undetectable by UV light. We therefore established a mass spectrometry method, designed for fast and convenient analysis, for simultaneously measuring 5-FdUrd, 5-FU, and their metabolites. Linearity, precision and accuracy were validated in the concentration ranges studied for each compound. Hydrolysis studies of 5-FdUrd and amino acid mono ester prodrugs of 5-FdUrd in Capan-2 cell homogenates were carried out and the achievement of mass balance was established with this method (recovery of 5'-O-l-leucyl-FdUrd was 96.6-108.2% and that of 5-FdUrd was 79.4-117.4%). This simple LC-MS method achieves reliable quantitation and mass balance of 5-FdUrd, 5-FU, and their metabolites and can be effectively utilized for further kinetic studies.
authors: Department of Pharmaceutical Science, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109-1065, USA.
authors: Yasuhiro
authors: Y
authors: Tsume
authors: Chester J
authors: CJ
authors: Provoda
authors: Gordon L
authors: GL
authors: Amidon
mesh_terms: D000704:Analysis of Variance; D000964:Antimetabolites, Antineoplastic / Q000032:analysis / Q000378:metabolism; D002457:Cell Extracts / Q000737:chemistry; D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005467:Floxuridine / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism; D005472:Fluorouracil / Q000032:analysis* / Q000378:metabolism; D006801:Humans; D016014:Linear Models; D013058:Mass Spectrometry / Q000379:methods*; D015203:Reproducibility of Results; D014498:Uracil / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism; D014508:Urea / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism; D015091:beta-Alanine / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism
chemical_list: D000964:Antimetabolites, Antineoplastic; D002457:Cell Extracts; C007419:dihydrouracil; D005467:Floxuridine; D015091:beta-Alanine; C032348:alpha-fluoro-beta-alanine; C045635:alpha-fluoro-beta-ureidopropionic acid; D014498:Uracil; D014508:Urea; D005472:Fluorouracil