title: Isolation of an unknown metabolite of capecitabine, an oral 5-fluorouracil prodrug, and its identification by nuclear magnetic resonance and liquid chromatography-tandem mass spectrometry as a glucuroconjugate of 5'-deoxy-5-fluorocytidine, namely 2'-(beta-D-glucuronic acid)-5'-deoxy-5-fluorocytidine.
abstract: A new metabolite of capecitabine, a prodrug of 5-fluorouracil, was detected by (19)F NMR in bile and liver of rats treated with this anticancer drug. Crude bile and perchloric acid extract of liver was subjected to liquid-liquid separation followed by a pre-purification step on a preparative octadecyl silane column (C(18)). The compound was purified by HPLC optimised to allow the detection of the unknown metabolite and its assumed precursor 5'-deoxy-5-fluorocytidine (5'-DFCR). Treatment with beta-glucuronidase from three sources showed that it was a glucuroconjugate of 5'-DFCR. HPLC-TIS-MS-MS and (1)H NMR allowed identification of the unknown metabolite as 2'-(beta-D-glucuronic acid)-5'-deoxy-5-fluorocytidine.
authors.affiliation: Biomedical NMR Group, IMRCP Laboratory, Université Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse, France. desmouli@chimie.ups-tlse.fr
authors.forename: Franck
authors.initials: F
authors.lastname: Desmoulin
authors.forename: Véronique
authors.initials: V
authors.lastname: Gilard
authors.forename: Robert
authors.initials: R
authors.lastname: Martino
authors.forename: Myriam
authors.initials: M
authors.lastname: Malet-Martino
mesh_terms: D000818:Animals; D001646:Bile / Q000378:metabolism; D000069287:Capecitabine; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D005472:Fluorouracil / Q000378:metabolism*; D006001:Glycoconjugates / Q000032:analysis* / Q000737:chemistry; D008099:Liver / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D011355:Prodrugs / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D006001:Glycoconjugates; D011355:Prodrugs; D003841:Deoxycytidine; D000069287:Capecitabine; C418208:5'-deoxy-5-fluorocytidine; D005472:Fluorouracil