title: Synthesis, characterization, and application of substituted pyrazolopyrimidine nucleosides.
abstract: This unit describes, in detail, the preparation of 3-aminopropyl-substituted pyrazolo[3,4-d]pyrimidine analogs of the purines deoxyadenosine (dA) and deoxyguanosine (dG). Phosphoramidite reagents of these so-called aminopropyl-PPA and -PPG nucleosides (AP-PPA and AP-PPG, respectively) allow introduction of amino linkers into internal positions of synthetic DNA strands. Synthesis of suitably protected AP-PPA and AP-PPG phosphoramidites are described. The stepwise alkynylation, hydrogenation, selective protection, and phosphoramidite synthesis is similar for both the PPA and PPG analogs. To demonstrate the application of these reagents, a protocol is given in which a simple DNA strand is synthesized and conjugated to a lipophilic activated ester (dabcyl-SE) to form a stable amide linkage. Utility of this chemistry for preparing internally modified DNA conjugates is discussed.
authors.affiliation: Epoch Biosciences, Bothell, Washington.
authors.forename: Robert O
authors.initials: RO
authors.lastname: Dempcy
authors.affiliation: Epoch Biosciences, Bothell, Washington.
authors.forename: Mikhail A
authors.initials: MA
authors.lastname: Podyminogin
authors.affiliation: Epoch Biosciences, Bothell, Washington.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Reed
mesh_terms: D003432:Cross-Linking Reagents; D004247:DNA / Q000138:chemical synthesis; D003839:Deoxyadenosines; D003849:Deoxyguanosine / Q000031:analogs & derivatives; D009943:Organophosphorus Compounds; D011720:Pyrazoles / Q000138:chemical synthesis*; D011741:Pyrimidine Nucleosides / Q000138:chemical synthesis*
chemical_list: D003432:Cross-Linking Reagents; D003839:Deoxyadenosines; D009943:Organophosphorus Compounds; D011720:Pyrazoles; D011741:Pyrimidine Nucleosides; C434331:phosphoramidite; D004247:DNA; D003849:Deoxyguanosine