Oligodeoxynucleotides containing phosphoramidate internucleotide links 3'-OP(O)NH-5' have been prepared using standard solid phase phosphoramidite techniques. For the incorporation of the phosphoramidate linkages we have used monomer as well as dimer building blocks. With the monomer 3'-phosphoramidite building blocks, which are derived from 5'-amino-2',5'-dideoxynucleosides, it is possible to incorporate phosphoramidate links into specific positions within an oligodeoxynucleotide. Furthermore the synthesis of several dinucleoside phosphate derivatives which are linked by phosphoramidate bonds are described. The internucleotide phosphoramidate linkage was performed using the Staudinger reaction followed by a Michaelis-Arbuzov type transformation. After 3'-phosphitylation these dinucleosides are compatible with the current phosphoramidite methodology of oligodeoxynucleotide synthesis.
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http://dx.doi.org/10.1093/nar/17.15.5973 | DOI Listing |
Int J Mol Sci
December 2024
Department of Physics, Novosibirsk State University, 2 Pirogov Str., Novosibirsk 630090, Russia.
Nowadays, nucleic acid derivatives capable of modulating gene expression at the RNA level have gained widespread recognition as promising therapeutic agents. A suitable degree of biological stability of oligonucleotide therapeutics is required for in vivo application; this can be most expeditiously achieved by the chemical modification of the internucleotidic phosphate group, which may also affect their cellular uptake, tissue distribution and pharmacokinetics. Our group has previously developed a strategy for the chemical modification of the phosphate group via the Staudinger reaction on a solid phase of the intermediate dinucleoside phosphite triester and a range of, preferably, electron deficient organic azides such as sulfonyl azides during automated solid-phase DNA synthesis according to the conventional β-cyanoethyl phosphoramidite scheme.
View Article and Find Full Text PDFInt J Mol Sci
January 2024
Institute of Chemical Biology and Fundamental Medicine, SB RAS, 8 Lavrentiev Avenue, 630090 Novosibirsk, Russia.
Detection of the Kirsten rat sarcoma gene () mutational status is an important factor for the treatment of various malignancies. The most common -activating mutations are caused by single-nucleotide mutations, which are usually determined by using PCR, using allele-specific DNA primers. Oligonucleotide primers with uncharged or partially charged internucleotide phosphate modification have proved their ability to increase the sensitivity and specificity of various single nucleotide mutation detection.
View Article and Find Full Text PDFACS Omega
January 2023
Institute of Chemical Biology and Fundamental Medicine, SB of RAS, pr. Lavrent'eva 8, 630090 Novosibirsk, Russia.
In this work, we present new oligonucleotide derivatives containing inter-nucleotide -benzimidazole, -benzoxazole, -benzothiazole, and 1,3-dimethyl--benzimidazole (benzoazoles) phosphoramide groups. These modifications were introduced via the Staudinger reaction with appropriate azides during standard automated solid-phase oligonucleotide synthesis. The principal structural difference between the new azido modifiers and those already known is that they are bulk heterocyclic structures, similar to purine nucleoside bases.
View Article and Find Full Text PDFNucleic Acid Ther
October 2022
Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., Carlsbad, California, USA.
Antisense oligonucleotides (ASOs) that mediate RNA target degradation by RNase H1 are used as drugs to treat various diseases. Previously we found that introduction of a single 2'--methyl (2'-OMe) modification in position 2 of the central deoxynucleotide region of a gapmer phosphorothioate (PS) ASO, in which several residues at the termini are 2'-methoxyethyl, 2' constrained ethyl, or locked nucleic acid, dramatically reduced cytotoxicity with only modest effects on potency. More recently, we demonstrated that replacement of the PS linkage at position 2 or 3 in the gap with a mesyl-phosphoramidate (MsPA) linkage also significantly reduced toxicity without meaningful loss of potency and increased the elimination half-life of the ASOs.
View Article and Find Full Text PDFNucleic Acid Ther
June 2021
Department of Paediatrics and Anatomy and Genetics, University of Oxford, Oxford, United Kingdom.
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