An ESI-MS and NMR study of the self-assembly of guanosine derivatives

The self-assembly of guanosine (G) derivatives in the presence of alkali-metal ions gives octameric or polymeric aggregates composed of stacked G quartets. This process is studied for some lipophilic G derivatives by means of ESI-MS. The ESI-MS results are discussed in the light of complementary information obtained from NMR and SANS (small-angle neutron scattering) studies. ESI-MS gives an excellent picture of the self-assembly process and gives new information on the effect of different cations and anions on the dimensions of the assembled species, information that could not have been obtained with SANS and NMR alone.