Use of a 13C atom to differentiate two 15N-labeled nucleosides

Article abstract of DOI:10.1021/jo971206u

We report the first examples of the specifically ¹⁵N and ¹³C multilabeled nucleosides: [1,NH₂-¹⁵N₂]- and [2-¹³C-1,NH₂-¹⁵N₂-]- guanosine; [1,7,NH₂-¹⁵N₃]- and [2-¹³C-1,7,NH₂-¹⁵N₃]-2'- deoxyguanosine. In each set, the [¹³C] atom functions as a 'tag' that allows the N1 and N2 ¹⁵N atoms of two ¹⁵N-labeled guanines to be unambiguously differentiated in RNA and DNA fragments. The syntheses employ high-yield reactions in which protecting groups are not required and use relatively low cost sources of isotopes: [¹⁵N]-ammonium chloride and [¹⁵N]- or [¹³C,¹⁵N]-potassium cyanide.