title: Base-modified oligodeoxyribonucleotides: using pyrrolo[2,3-d]pyrimidines to replace purines.
abstract: Phosphoramidites are first synthesized from suitably protected 7-deazapurine 2'-deoxyribonuclosides that have halogen or alkynyl subsituents at the 7 position. Oligonucleotides containing 7-deazapurines (pyrrolo[2,3-d]pyrimidines) in place of the canonical nucleobases are then prepared by solid-phase synthesis. These oligonucleotides are subsequently allowed to hybridize, and the stabilities of the resulting duplexes are determined. Comparison of T(m) values indicates that the presence of 7-halo or 7-alkynyl substituents increases duplex stability relative to duplexes involving oligonucleotides that contain the corresponding parent purines.
authors.affiliation: Universität Osnabrück Osnabrück, Germany, Osnabrück, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Seela
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Peng
mesh_terms: D009838:Oligodeoxyribonucleotides / Q000737:chemistry*; D009841:Oligonucleotides / Q000737:chemistry* / Q000302:isolation & purification; D009943:Organophosphorus Compounds / Q000737:chemistry; D011687:Purines / Q000737:chemistry*; D011720:Pyrazoles / Q000737:chemistry*; D011743:Pyrimidines / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D009838:Oligodeoxyribonucleotides; D009841:Oligonucleotides; D009943:Organophosphorus Compounds; D011687:Purines; D011720:Pyrazoles; D011743:Pyrimidines; C434331:phosphoramidite; C014175:pyrazolo(3,4-d)pyrimidine