Design, synthesis and evaluation of molecularly targeted hypoxia-activated prodrugs

Nat Protoc. 2016 Apr;11(4):781-94. doi: 10.1038/nprot.2016.034. Epub 2016 Mar 24.

Abstract

Regions of insufficient oxygen supply-hypoxia-occur in diverse contexts across biology in both healthy and diseased organisms. The difference in the chemical environment between a hypoxic biological system and one with normal oxygen levels provides an opportunity for targeting compound delivery to hypoxic regions by using bioreductive prodrugs. Here we detail a protocol for the efficient synthesis of (1-methyl-2-nitro-1H-imidazol-5-yl)methanol, which is a key intermediate that can be converted into a range of 1-methyl-2-nitro-1H-imidazole-based precursors of bioreductive prodrugs. We outline methods for attaching the bioreductive group to a range of functionalities, and we discuss the strategy for positioning of the group on the biologically active parent compound. We have used two parent checkpoint kinase 1 (Chk1) inhibitors to exemplify the protocol. The PROCEDURE also describes a suite of reduction assays, of increasing biological relevance, to validate the bioreductive prodrug. These assays are applied to an exemplar compound, CH-01, which is a bioreductive Chk1 inhibitor. This protocol has broad applications to the development of hypoxia-targeted compounds.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / chemical synthesis*
  • Antineoplastic Agents / pharmacology
  • Cell Line, Tumor
  • Checkpoint Kinase 1
  • Enzyme Inhibitors / chemical synthesis*
  • Enzyme Inhibitors / pharmacology
  • Humans
  • Hypoxia*
  • Metronidazole / analogs & derivatives*
  • Metronidazole / chemical synthesis
  • Metronidazole / pharmacology
  • Prodrugs / chemical synthesis*
  • Prodrugs / pharmacology
  • Protein Kinases / metabolism*
  • Technology, Pharmaceutical / methods

Substances

  • Antineoplastic Agents
  • Enzyme Inhibitors
  • Prodrugs
  • Metronidazole
  • Protein Kinases
  • CHEK1 protein, human
  • Checkpoint Kinase 1