title: Base-modified oligonucleotides with increased duplex stability: pyrazolo[3,4-d] pyrimidines replacing purines.
abstract: Oligonucleotides incorporating 8-aza-7-dazapurines (pyrazolo[3,4-d]pyrimidines) were synthesized. The corresponding nucleosides were prepared and were converted into phosphoramidites. The oligonucleotide duplex stability was studied and was compared to that of the parent compounds containing the canonical purine nucleosides. The presence of 7-halogeno or 7-alkynyl substituents increases the duplex stability significantly.
authors.affiliation: Laboratorium für Organishe und Bioorganische Chemie, Institut für Chemie, Unversität Osnabrück, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Seela
authors.forename: Yang
authors.initials: Y
authors.lastname: He
authors.forename: Junlin
authors.initials: J
authors.lastname: He
authors.forename: Georg
authors.initials: G
authors.lastname: Becher
authors.forename: Rita
authors.initials: R
authors.lastname: Kröschel
authors.forename: Matthias
authors.initials: M
authors.lastname: Zulauf
authors.forename: Peter
authors.initials: P
authors.lastname: Leonard
mesh_terms: D001483:Base Sequence; D002855:Chromatography, Thin Layer; D019906:Nuclear Magnetic Resonance, Biomolecular; D009841:Oligonucleotides / Q000737:chemistry*; D011687:Purines / Q000737:chemistry*; D011720:Pyrazoles / Q000737:chemistry*; D011743:Pyrimidines / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D009841:Oligonucleotides; D011687:Purines; D011720:Pyrazoles; D011743:Pyrimidines; C014175:pyrazolo(3,4-d)pyrimidine