606972-27-4Relevant academic research and scientific papers
2′-: O -Methyl- and 2′- O -propargyl-5-methylisocytidine: Synthesis, properties and impact on the isoCd-dG and the isoCd-isoGd base pairing in nucleic acids with parallel and antiparallel strand orientation
Jana, Sunit K.,Leonard, Peter,Ingale, Sachin A.,Seela, Frank
, p. 4927 - 4942 (2016)
Oligonucleotides containing 2′-O-methylated 5-methylisocytidine (3) and 2′-O-propargyl-5-methylisocytidine (4) as well as the non-functionalized 5-methyl-2′-deoxyisocytidine (1b) were synthesized. MALDI-TOF mass spectra of oligonucleotides containing 1b are susceptible to a stepwise depyrimidination. In contrast, oligonucleotides incorporating 2′-O-alkylated nucleosides 3 and 4 are stable. This is supported by acid catalyzed hydrolysis experiments performed on nucleosides in solution. 2′-O-Alkylated nucleoside 3 was synthesized from 2′-O-5-dimethyluridine via tosylation, anhydro nucleoside formation and ring opening. The corresponding 4 was obtained by direct regioselective alkylation of 5-methylisocytidine (1d) with propargyl bromide under phase-transfer conditions. Both compounds were converted to phosphoramidites and employed in solid-phase oligonucleotide synthesis. Hybridization experiments resulted in duplexes with antiparallel or parallel chains. In parallel duplexes, methylation or propargylation of the 2′-hydroxyl group of isocytidine leads to destabilization while in antiparallel DNA this effect is less pronounced. 2′-O-Propargylated 4 was used to cross-link nucleosides and oligonucleotides to homodimers by a stepwise click ligation with a bifunctional azide.
Sugar conformational effects on the photochemistry of thymidylyl(3′-5′)thymidine
Ostrowski, Tomasz,Maurizot, Jean-Claude,Adeline, Marie-Therese,Fourrey, Jean-Louis,Clivio, Pascale
, p. 6502 - 6510 (2007/10/03)
The synthesis and conformational analysis of 2′-O,5-dimethyluridylyl(3′-5′)-2′-O,5-dimethyluridine (1a), the analogue of thymidylyl(3′-5′)thymidine (TpT; 1b) in which a methoxy group replaces each 2′-α-hydrogen atom, are described. In comparison with TpT, such modification increases the population of the C3′-endo conformer of the sugar ring puckering at the 5′- and 3′-ends from 30 to 75% and from 37 to 66%, respectively. Photolyses of 1a and TpT at 254 nm are qualitatively comparable (the cis-syn cyclobutane pyrimidine dimer and the (6-4) photoproduct are formed), although it is significantly faster in the case of 1a. These results are explained by the increased propensity of the modified dinucleotide to adopt a base-stacked conformation geometry reminiscent of that for TpT.
