Simplified and Cost Effective Syntheses of Fully Protected Phosphoramidite Monomers Suitable for the Assembly of Oligo(2′-O-allylribonucleotides)
摘要:
Simplified, high yielding syntheses of suitably protected 2'-O-allylribonucleoside-3'-O-phosphoramidites starting from standard ribonucleosides have been elucidated. Specific 2'-O-allylation is readily achieved using amidine protection of the exocyclic amino groups of adenosine and cytidine and in the case of guanosine the allylation is carried out on an easily prepared intermediate bearing transient protection of the lactam function.
2-Aza-2'-deoxyadenosine (2, z2Ad) is synthesized via its 1,N6-etheno derivative 7 and enzymatically deaminated to 2-aza-2'-deoxyinosine (3). Compound 2 is converted into the phosphoramidite buildingblock 10b. This is employed in solid-phase oligonucleotide synthesis. The 2-azapurine base forms a strong base pair with guanine, but a much weaker one with adenine, thymine, and cytosine. Oligonucleotide
[EN] MODIFIED CYTOSINE POLYNUCLEOTIDE OLIGOMERS AND METHODS<br/>[FR] OLIGOMÈRES POLYNUCLÉOTIDIQUES DE CYTOSINE MODIFIÉE ET PROCÉDÉS CORRESPONDANTS
申请人:CEPHEID
公开号:WO2015153510A1
公开(公告)日:2015-10-08
Disclosed are modified cytosine bases that provide enhanced base-pairing affinity for guanine bases in polynucleotide hybridization complexes. Also disclosed are polynucleotide oligomers, polynucleotide hybridization complexes that comprise such modified cytosine bases. Also disclosed are various methods of use. For example, in some embodiments, modified polynucleotide oligomers disclosed herein can be used as primers and probes for nucleic acid amplification and/or detection.
Non-standard nucleobases implementing the isocytidine and isoguanosine hydrogen bonding patterns
申请人:——
公开号:US07741294B1
公开(公告)日:2010-06-22
This invention provides compositions of matter that, when incorporated into an oligonucleotide, present to a complementary strand in a Watson-Crick pairing geometry a pattern of hydrogen bonds that is different from the pattern presented by adenine, guanine, cytosine, and thymine. Most specifically, this invention discloses and claims compositions of matter that present the same hydrogen bonding patterns as the isocytidine and isoguanosine nucleobases, but do not have unfavorable tautomeric forms, do not become disassociated from their sugar, and do not make major groove interactions, as much, as easily, or as strongly as isocytidine and isoguanosine.
same oligonucleotide chain. Parallel (ps) oligonucleotide duplexes are observed, when the β-D anomer 1 alternates with 2. A renewed reversal of the chain orientation (psaps) occurs when compound 1pairs with 2′-deoxyisoguanosine (6). In all cases, it is unnecessary to change the orientation within a single strand when α-D units alternate with their β-D counterparts. Heterochiral basepairs of 5 (α-D)
Cellular activity of siRNA oligonucleotides containing synthetic isomorphic nucleoside surrogates
作者:Dongwon Shin、Peter Lönn、Steven F. Dowdy、Yitzhak Tor
DOI:10.1039/c4cc08809c
日期:——
Singly and multiply modified synthetic siRNA oligonucleotides, containing highly isomorphic surrogate nucleobases, show high interference activity in cell culture.