title: Rigid 2',4'-difluororibonucleosides: synthesis, conformational analysis, and incorporation into nascent RNA by HCV polymerase.
abstract: We report on the synthesis and conformational properties of 2'-deoxy-2',4'-difluorouridine (2',4'-diF-rU) and cytidine (2',4'-diF-rC) nucleosides. NMR analysis and quantum mechanical calculations show that the strong stereoelectronic effects induced by the two fluorines essentially "lock" the conformation of the sugar in the North region of the pseudorotational cycle. Our studies also demonstrate that NS5B HCV RNA polymerase was able to accommodate 2',4'-diF-rU 5'-triphosphate (2',4'-diF-rUTP) and to link the monophosphate to the RNA primer strand. 2',4'-diF-rUTP inhibited RNA synthesis in dinucleotide-primed reactions, although with relatively high half-maximal inhibitory concentrations (IC50 > 50 μM). 2',4'-diF-rU/C represents rare examples of "locked" ribonucleoside mimics that lack a bicyclic ring structure.
authors.affiliation: Department of Chemistry, McGill University , 801 Sherbrooke Street West, Montreal, QC Canada H3A 0B8.
authors.forename: Saúl
authors.initials: S
authors.lastname: Martínez-Montero
authors.forename: Glen F
authors.initials: GF
authors.lastname: Deleavey
authors.forename: Anupriya
authors.initials: A
authors.lastname: Kulkarni
authors.forename: Nerea
authors.initials: N
authors.lastname: Martín-Pintado
authors.forename: Petra
authors.initials: P
authors.lastname: Lindovska
authors.forename: Michael
authors.initials: M
authors.lastname: Thomson
authors.forename: Carlos
authors.initials: C
authors.lastname: González
authors.forename: Matthias
authors.initials: M
authors.lastname: Götte
authors.forename: Masad J
authors.initials: MJ
authors.lastname: Damha
mesh_terms: D000998:Antiviral Agents / Q000138:chemical synthesis* / Q000737:chemistry; D003562:Cytidine / Q000737:chemistry*; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry* / Q000378:metabolism; D005467:Floxuridine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D020128:Inhibitory Concentration 50; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D012313:RNA / Q000737:chemistry*; D012263:Ribonucleosides / Q000138:chemical synthesis* / Q000737:chemistry; D017361:Viral Nonstructural Proteins / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology
chemical_list: C000593434:2'-deoxy-2',4'-difluorouridine; D000998:Antiviral Agents; D012263:Ribonucleosides; D017361:Viral Nonstructural Proteins; D005467:Floxuridine; D003562:Cytidine; D012313:RNA; D012321:DNA-Directed RNA Polymerases