Pharmaceutical Research

, Volume 20, Issue 9, pp 1381–1388 | Cite as

Amino Acid Ester Prodrugs of Floxuridine: Synthesis and Effects of Structure, Stereochemistry, and Site of Esterification on the Rate of Hydrolysis

  • Balvinder S. Vig
  • Philip J. Lorenzi
  • Sachin Mittal
  • Christopher P. Landowski
  • Ho-Chul Shin
  • Henry I. Mosberg
  • John M. Hilfinger
  • Gordon L. Amidon


Purpose. To synthesize amino acid ester prodrugs of floxuridine (FUdR) and to investigate the effects of structure, stereochemistry, and site of esterification of promoiety on the rates of hydrolysis of these prodrugs in Caco-2 cell homogenates.

Methods. Amino acid ester prodrugs of FUdR were synthesized using established procedures. The kinetics of hydrolysis of prodrugs was evaluated in human adenocarcinoma cell line (Caco-2) homogenates and pH 7.4 phosphate buffer.

Results. 3′-Monoester, 5′-monoester, and 3′,5′-diester prodrugs of FUdR utilizing proline, L-valine, D-valine, L-phenylalanine, and D-phenylalanine as promoieties were synthesized and characterized. In Caco-2 cell homogenates, the L-amino acid ester prodrugs hydrolyzed 10 to 75 times faster than the corresponding D-amino acid ester prodrugs. Pro and Phe ester prodrugs hydrolyzed much faster (3- to 30-fold) than the corresponding Val ester prodrugs. Further, the 5′-monoester prodrugs hydrolyzed significantly faster (3-fold) than the 3′,5′-diester prodrugs.

Conclusions. Novel amino acid ester prodrugs of FUdR were successfully synthesized. The results presented here clearly demonstrate that the rate of FUdR prodrug activation in Caco-2 cell homogenates is affected by the structure, stereochemistry, and site of esterification of the promoiety. Finally, the 5′-Val and 5′-Phe monoesters exhibited desirable characteristics such as good solution stability and relatively fast enzymatic conversion rates.

floxuridine prodrug hydrolysis stability amino acid Caco-2 


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Copyright information

© Plenum Publishing Corporation 2003

Authors and Affiliations

  • Balvinder S. Vig
    • 1
  • Philip J. Lorenzi
    • 1
  • Sachin Mittal
    • 1
  • Christopher P. Landowski
    • 1
  • Ho-Chul Shin
    • 1
  • Henry I. Mosberg
    • 2
  • John M. Hilfinger
    • 3
  • Gordon L. Amidon
    • 1
  1. 1.Department of Pharmaceutical Sciences, College of PharmacyUniversity of MichiganAnn Arbor
  2. 2.Department of Medicinal Chemistry, College of PharmacyUniversity of MichiganAnn Arbor
  3. 3.TSRL Inc.Ann Arbor

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