Nebularine (purine riboside) lacks exocyclic functional groups and offers an altered hydrogen bonding scheme while retaining base stacking ability.⁽¹⁾ It can be viewed as an adenosine analogue with the hydrogen bond donor deleted. Sequential replacement of conserved adenosine residues in hammerhead ribozymes by nebularine residues^1c,d suggested the presence of interstrand non-Watson-Crick hydrogen bonding.^1c Depending on the position of the nebularine residue, cleavage rates were either unchanged or diminished.^1c,d Incorporation of nebularine into a GNRA tetraloop has also been useful for studying this type of RNA structural feature.^1e Nebularine has been installed into RNA using two different phosphoramidites, one with 2'-O-THP protection^1a and one with 2'-O-TBDMS protection.^1b-e We offer the latter, Nebularine-CE Phosphoramidite (BA0265) as well as the 2-deoxy version (BA0016).

Ref:

1. (a) SantaLucia, J., Jr.; Kierzek, R.; Turner, D. H. J. Am. Chem. Soc. 1991, 113, 4313-4322. (b) Slim, G.; Pritchard, C.; Biala, E.; Asseline, U.; Gait, M. J. Nucleic Acids Symp. Ser. 1991, 24, 55-58. (c) Slim, G.; Gait, M. J. Biochem. Biophys. Res. Commun. 1991, 183, 605-609. (d) Fu, D.-J.; Rajur, S.; McLaughlin, L. W. Biochemistry 1993, 32, 10629-10673. (e) Wörner, K.; Strube, T.; Engels, J. W. Helv. Chim. Acta 1999, 82, 2094-2104.