Synthesis of 1-Deazaadenosine Analogues of (2′→5′) ApApA

TheHigh-Anti Conformation of 7-Halogenated 8-Aza-7-deaza-2′-deoxy-guanosines: A Study of the Influence of Modified Bases on the Sugar Structure of Nucleosides

“…Unusually high or low c values which deviate strongly from the graph are the result of intramolecular H-bonds or steric interactions (repulsion or attraction). Examples are guanosine, 2'-deoxyguanosine, or 1-deazaguanosine [34] [35]. Here, a H-bond between the 5'-OH group in the sc (g ) conformation and either N(3) (1-deazapurines) or the 2-NH 2 group of guanine causes the relatively unusual syn conformation of the base ( Figs.…”

Synthesis and Adenosine Deaminase Inhibitory Activity of 3′-Deoxy-1-deazaadenosines

“…However, since no NOE was observed on the 7-NH 2 group in compounds 6 and 9, the presence of N(1)-regioisomers can be excluded [19] [20]. This assignment was also unequivocal for the chloro compounds 5 and 8, as the amino compounds were obtained from the chloro derivatives.…”

Modified (2′,5′)Oligonucleotides: The Influence of Structural and Steriochemical Factors on Biological and Immunotropic Activity

“…Substitution of the adenosine moiety with 1-deazaadenosine (c 1 A) or 3-deazaadenosine (c 3 A) at different positions of the 2-5A chain first allowed to establish the role played by each of the adenine heterocycle nitrogen atoms in RNase L binding and activation [20][21][22].…”

“…Thus, previous data did not allow us to draw a definite conclusion as to what caused the loss of binding and/or activating ability of the above analogs substituted for inosine-the loss of exocyclic adenosine NH 2 -C6 group or transition of the tertiary adenine N1 nitrogen atom to the secondary atom in hypoxanthine? The use of 2-5A 1-deazaadenosine analogs resolved the above ambiguity since the substitution of adenosine by 1-deazaadenosine removes solely the adenine N1 nitrogen atom turning it into a CH moiety yet leaving the exocyclic primary amino function unchanged (Figure 2) [20,21].…”