title: Synthesis and biological investigations of 5-substituted pyrimidine nucleosides coupled to a dihydropyridine/pyridinium salt redox chemical delivery system.
abstract: The syntheses, antiviral activities, and partition coefficients (P) of 3'-O-(1-methyl-1,4-dihydropyridyl-3-carbonyl)-coupled nucleosides are described. These novel compounds were designed in an effort to enhance the lipophilicity, and thereby the delivery to the CNS, without compromising the anti-HSV-1 activity of the parental nucleosides. We have previously reported the synthesis of 3'-O-(1-methyl-1,4-dihydropyridyl-3- carbonyl) analogs of 5-iodo-(5), 5-vinyl-(6), and (E)-5-(2-iodovinyl)-2'-deoxyuridines (7). We now report the synthesis of 5-iodo-3'-O-(1-methyl-1,4-dihydropyridyl-3- carbonyl)-5'-O-acetyl-2'-deoxyuridine (15) and 3'-O-(1-methyl-1,4-dihydropyridyl-3-carbonyl)-2'-deoxyuridine (17). Quarternization of the 3'-O-(3-pyridylcarbonyl) compounds (10,12) using iodomethane afforded the corresponding 1-methyl pyridinium salts (13,14) which were reduced with sodium dithionite to yield the corresponding 3'-O-1-methyl-1,4-dihydropyridyl-3-carbonyl compounds (15,16). The deprotection of 3'-O-(1-methyl-1,4-dihydropyridyl- 3-carbonyl)-5'-O-t-butyldimethylsilyl-2'-deoxyuridine (16) with Bu4N+F- afforded 3'-O-(1-methyl-1,4-dihydropyridyl-3-carbonyl)-2'-deoxyuridine (17). Compounds 5-7 and 15 were evaluated for their antiviral activity in vitro against HSV-1, HSV-2, HCMV, and VZV, and were found to retain anti-HSV-1, HSV-2 and VZV activity as compared to their parental nucleosides (1-3). In addition, the cellular toxicity of 3'-O-(1-methyl-1,4-dihydropyridyl-3-carbonyl)-coupled compounds (5-7 and 15) was found to be lower than the parent nucleosides. The lipophilicity of compounds (5-7,15,17) are enhanced substantially, compared to the parent nucleosides, as indicated by an increase in corresponding P values (1-octanol-water) upon replacement of the C-3' hydroxyl by 1-methyl-1,4-dihydropyridyl-3-carbonyl moiety.
authors.affiliation: Department of Medical Microbiology and Immunology, Faculty of Medicine, University of Alberta, Edmonton T6G 2H7, AB, Canada. rakesh.kumar@ualberta.ca
authors.forename: R
authors.initials: R
authors.lastname: Kumar
authors.forename: L
authors.initials: L
authors.lastname: Wang
authors.forename: L I
authors.initials: LI
authors.lastname: Wiebe
authors.forename: E E
authors.initials: EE
authors.lastname: Knaus
mesh_terms: D000998:Antiviral Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D003587:Cytomegalovirus / Q000187:drug effects; D014645:Herpesvirus 3, Human / Q000187:drug effects; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D011355:Prodrugs / Q000138:chemical synthesis / Q000494:pharmacology; D011741:Pyrimidine Nucleosides / Q000138:chemical synthesis / Q000494:pharmacology*; D018139:Simplexvirus / Q000187:drug effects; D013329:Structure-Activity Relationship
chemical_list: D000998:Antiviral Agents; D011355:Prodrugs; D011741:Pyrimidine Nucleosides