Development and bioorthogonal activation of palladium-labile prodrugs of gemcitabine

J Med Chem. 2014 Jun 26;57(12):5395-404. doi: 10.1021/jm500531z. Epub 2014 Jun 12.

Abstract

Bioorthogonal chemistry has become one of the main driving forces in current chemical biology, inspiring the search for novel biocompatible chemospecific reactions for the past decade. Alongside the well-established labeling strategies that originated the bioorthogonal paradigm, we have recently proposed the use of heterogeneous palladium chemistry and bioorthogonal Pd(0)-labile prodrugs to develop spatially targeted therapies. Herein, we report the generation of biologically inert precursors of cytotoxic gemcitabine by introducing Pd(0)-cleavable groups in positions that are mechanistically relevant for gemcitabine's pharmacological activity. Cell viability studies in pancreatic cancer cells showed that carbamate functionalization of the 4-amino group of gemcitabine significantly reduced (>23-fold) the prodrugs' cytotoxicity. The N-propargyloxycarbonyl (N-Poc) promoiety displayed the highest sensitivity to heterogeneous palladium catalysis under biocompatible conditions, with a reaction half-life of less than 6 h. Zebrafish studies with allyl, propargyl, and benzyl carbamate-protected rhodamines confirmed N-Poc as the most suitable masking group for implementing in vivo bioorthogonal organometallic chemistry.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antimetabolites, Antineoplastic / chemistry*
  • Antimetabolites, Antineoplastic / metabolism
  • Antimetabolites, Antineoplastic / pharmacology
  • Carbamates / chemistry
  • Carbamates / metabolism
  • Carbamates / pharmacology
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • DNA Damage
  • Deoxycytidine / analogs & derivatives*
  • Deoxycytidine / chemistry
  • Deoxycytidine / pharmacology
  • Drug Carriers
  • Drug Screening Assays, Antitumor
  • Embryo, Nonmammalian / metabolism
  • Gemcitabine
  • Humans
  • Nanoparticles
  • Palladium / chemistry*
  • Polystyrenes
  • Prodrugs / chemistry*
  • Prodrugs / metabolism
  • Prodrugs / pharmacology
  • Rhodamines / chemistry
  • Rhodamines / metabolism
  • Rhodamines / pharmacology
  • Structure-Activity Relationship
  • Zebrafish

Substances

  • Antimetabolites, Antineoplastic
  • Carbamates
  • Drug Carriers
  • Polystyrenes
  • Prodrugs
  • Rhodamines
  • Deoxycytidine
  • Palladium
  • Gemcitabine