A series of isonucleotide incorporated antisense oligodeoxynucleotides have been synthesized, in which isonucleotide was introduced at different positions of the sequences. The results showed that though the incorporated isonucleotides at different position of the sequence interfered in the binding ability in different extent, B-form duplexes were maintained and the binding abilities of the 3′-end modified duplexes were better than the corresponding mismatched duplexes. The DNA/RNA hybrid formed by modified oligodeoxynucleotide and its target RNA could activate the activity of RNase H. The 3′-end modified antisense oligodeoxynucelotides showed the inhibition on S glycoprotein expression of SARS-CoV at the mRNA levels in insect Sf9 cells. In this presentation, a novel class of amino-isonucleoside was synthesized and incorporated into different positions in the sense or antisense strand of siRNA duplexes. The 3′ and 5′ sense strand aminonucleoside modified siRNAs (ssISO-siRNA1 and ssISO-siRNA2) showed the similar duplex thermal and serum stability as natural one and the luciferase activities showed that such modified siRNA is compatible with the intracellular siRNA machinery. Copyright Taylor & Francis Group, LLC.
Zhang, Li He,Yang, Zhen Jun,Zhang, Liang Ren
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p. 326 - 334
(2009/05/07)
One-step synthesis of novel tricyclic isomeric azidonucleosides
Several tricyclic azido-isonucleosides were formed in high yields by the treatment of pyrimidine isonucleosides with triphenylphosphine, tetrabromomethane, and sodium azide. The regioselective ring opening of these tricyclic azido-isonucleosides was also