title: Synthesis and application of novel nucleoside phosphonates and phosphoramidites modified at the base moiety.
abstract: The H-phosphonates and phosphoramidites of 2'-deoxyisoguanosine, 2'-deoxyisoinosine, 5-aza-7-deaza-2'-deoxyguanosine, and N1-methyl-2'-deoxyformycin A were prepared. The diphenylcarbamoyl group was chosen for the 2-O-protection of 2'-deoxyisoinosine and 2'-deoxyisoguanosine, and dimethylaminoalkylidene groups were used to block the amino function of the various monomers. The synthesis of isoguanine oligonucleotides was found to be much more efficient using the 2-O-protected building blocks compared to those without oxygen protection. Oligodeoxynucleotides containing 2'-deoxyisoguanosine and 2'-deoxycytidine form parallel duplex structures. The self-complementary duplex containing 5-aza-7-deaza-2'-deoxyguanosine and 2'-deoxycytidine forms a stable duplex in acidic solution (pH = 5.0) while it is destabilized under neutral conditions.
authors.affiliation: Laboratorium für Organische und Bioorganische Chemie, Universität Osnabrück, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Seela
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
authors.forename: A
authors.initials: A
authors.lastname: Melenewski
authors.forename: H
authors.initials: H
authors.lastname: Rosemeyer
authors.forename: C
authors.initials: C
authors.lastname: Wei
mesh_terms: D000577:Amides; D001483:Base Sequence; D006860:Hydrogen Bonding; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009705:Nucleosides / Q000138:chemical synthesis* / Q000737:chemistry*; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis* / Q000737:chemistry; D016376:Oligonucleotides, Antisense / Q000138:chemical synthesis / Q000737:chemistry; D063065:Organophosphonates; D010756:Phosphoric Acids; D011687:Purines
chemical_list: D000577:Amides; D007202:Indicators and Reagents; D009705:Nucleosides; D009838:Oligodeoxyribonucleotides; D016376:Oligonucleotides, Antisense; D063065:Organophosphonates; D010756:Phosphoric Acids; D011687:Purines; C011067:phosphoramidic acid