Sugar-thioacetamide backbone in oligodeoxyribonucleosides for specific recognition of nucleic acids

Triazole-linked analogues of DNA and RNA ((TL)DNA and (TL)RNA): synthesis and functions

Click chemistry has provided us with access to DNA and RNA analogues with non-natural triazole internucleoside linkages. The bond periodicity of the oligonucleotides was designed to enforce duplex formation with natural congeners, and the non-cleavable linkages protect the oligomers against nuclease digestion. This account reviews the progress of the triazole-linked analogues over the past five years. Reinforced by their synthetic robustness, these analogues may find various utilities as tools for exploratory research.

Design and synthesis of dephosphono DNA analogues containing 1,2,3-triazole linker and their UV-melting studies with DNA/RNA

This article describes the synthesis of 3'/5' linked 1,2,3-triazolyl dithymidine derivatives, their incorporation into oligonucleotides, and evaluation of their thermal stabilities toward complementary DNA/RNA.

Synthesis of ether-linked oligoribo- and xylonucleosides from 3,5'-ether-linked pseudosaccharides

First examples of di- and trinucleosides with ribose and xylose stereochemistry having internucleoside ether linkage were synthesized from 3,5'-ether-linked pseudosaccharides. The synthetic protocol involved removal of 1,2-isopropylidene protecting groups from the pseudosaccharides followed by acetylation and a subsequent Vorbruggen transglycosylation with uracil and N-benzoylaminopurine. The synthetic strategy is potentially important for the development of RNA analogues with internucleoside ether linkage.

A versatile method for the preparation of conjugates of peptides with DNA/PNA/analog by employing chemo-selective click reaction in water

The specific 1,3 dipolar Hüisgen cycloaddition reaction known as 'click-reaction' between azide and alkyne groups is employed for the synthesis of peptide-oligonucleotide conjugates. The peptide nucleic acids (PNA)/DNA and peptides may be appended either by azide or alkyne groups. The cycloaddition reaction between the azide and alkyne appended substrates allows the synthesis of the desired conjugates in high purity and yields irrespective of the sequence and functional groups on either of the two substrates. The versatile approach could also be employed to generate the conjugates of peptides with thioacetamido nucleic acid (TANA) analog. The click reaction is catalyzed by Cu (I) in either water or in organic medium. In water, approximately 3-fold excess of the peptide-alkyne/azide drives the reaction to completion in 2 h with no side products.

N-Methyl substituted 2',4'- BNANC: a highly nuclease-resistant nucleic acid analogue with high-affinity RNA selective hybridization

Oligonucleotides modified with a novel BNA analogue, 2', 4'-BNA(NC)[N-Me], were synthesized, and in comparison to 2',4'-BNA (LNA), have similarly high RNA affinity, better RNA selectivity and much higher resistance to nuclease degradation, suggesting that the novel BNA analogue may be particularly useful for antisense approaches.

Synthesis and RNA binding selectivity of oligonucleotides modified with five-atom thioacetamido nucleic acid backbone structures

Convenient chemical synthesis and incorporation of dithymidine and thymidine-cytidine dimer blocks connected with a five-atom amide linker N3'-CO-CH2-S-CH2 into oligonucleotides (ONs) are reported. The UV-Tm experiments for binding affinities of these mixed backbone ONs with complementary DNA and RNA sequences revealed important results such as significantly higher RNA-binding selectivity as compared with complementary DNA. NMR studies of the dimer blocks suggested a marginal increase in the N-type sugar conformations over that of the native DNA.