title: Design, synthesis and evaluation of molecularly targeted hypoxia-activated prodrugs.
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.
authors.affiliation: Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, UK.|Department of Oncology, Cancer Research UK (CRUK)/Medical Research Council (MRC) Institute for Radiation Oncology, University of Oxford, Oxford, UK.
authors.forename: Liam J
authors.initials: LJ
authors.lastname: O'Connor
authors.affiliation: Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, UK.|Department of Oncology, Cancer Research UK (CRUK)/Medical Research Council (MRC) Institute for Radiation Oncology, University of Oxford, Oxford, UK.
authors.forename: Cindy
authors.initials: C
authors.lastname: Cazares-Körner
authors.affiliation: Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, UK.
authors.forename: Jaideep
authors.initials: J
authors.lastname: Saha
authors.affiliation: Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, UK.|Department of Oncology, Cancer Research UK (CRUK)/Medical Research Council (MRC) Institute for Radiation Oncology, University of Oxford, Oxford, UK.
authors.forename: Charles N G
authors.initials: CN
authors.lastname: Evans
authors.affiliation: Department of Oncology, Cancer Research UK (CRUK)/Medical Research Council (MRC) Institute for Radiation Oncology, University of Oxford, Oxford, UK.
authors.forename: Michael R L
authors.initials: MR
authors.lastname: Stratford
authors.affiliation: Department of Oncology, Cancer Research UK (CRUK)/Medical Research Council (MRC) Institute for Radiation Oncology, University of Oxford, Oxford, UK.
authors.forename: Ester M
authors.initials: EM
authors.lastname: Hammond
authors.affiliation: Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, UK.
authors.forename: Stuart J
authors.identifier: http://orcid.org/0000-0002-5148-117X
authors.initials: SJ
authors.lastname: Conway
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D045744:Cell Line, Tumor; D000071877:Checkpoint Kinase 1; D004791:Enzyme Inhibitors / Q000138:chemical synthesis* / Q000494:pharmacology; D006801:Humans; D000860:Hypoxia; D008795:Metronidazole / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000494:pharmacology; D011355:Prodrugs / Q000138:chemical synthesis* / Q000494:pharmacology; D011494:Protein Kinases / Q000378:metabolism*; D013678:Technology, Pharmaceutical / Q000379:methods
chemical_list: D000970:Antineoplastic Agents; D004791:Enzyme Inhibitors; D011355:Prodrugs; D008795:Metronidazole; D011494:Protein Kinases; C000605867:CHEK1 protein, human; D000071877:Checkpoint Kinase 1