Abstract

Traditionally, isotope-labelled DNA and RNA have been fundamental to nucleicacid structural studies by NMR. Four-stranded nucleic acid architectures studiesincreasingly benefit from a plethora of nucleotide conjugates for resonance assignments,the identification of hydrogen bond alignments, and improving the population of preferredspecies within equilibria. In this paper, we review their use for these purposes. Mostimportantly we identify reasons for the failure of some modifications to result inquadruplex formation.