By the use of 31P NMR spectroscopy and other experimental techniques, supported by quantum-chemical calculations, we were able to show that reaction on model systems between dicyclopalladated azobenzenes and triphenylphosphine lead to the thermodynamically favorable bridged complexes. It was demonstrated for the first time that very complex molecular dynamics involving a series of structural transformations is feasible also in the solid state.
COBISS.SI-ID: 4800794
G-rich oligonucleotides with cytosine residues in their primary sequences can form G-quadruplexes where G-quartets are flanked by GC Watson-Crick base pairs. Solution state nuclear magnetic resonance was used in order to study the folding of the d(G3CT4G3C) oligonucleotide into a G-quadruplex upon addition of 15NH4+ ions. A single ammonium ion binding site was identified between adjacent G-quartets, although three sites were expected. A relatively fast movement of ammonium ions with the rate constants of 21 s-1 was detected from the inner binding site to bulk ssolution. The remaining two potential cation binding sites between G-quartets and GC base pairs are occupied by water molecules. This is the first observation of long-lived water molecules within a G-quadruplex structure.
COBISS.SI-ID: 4651802
Regioisomers of novel N-methoxymethylated (MOM) pyrimidines were assessed with the use of 1H, 13C and 19F NMR spectroscopy. This model study of nucleoside mimetic compounds included determination of pyrimidines' conformational properties. Furthermore, fluorinated N,N-1,3-diMOM pyrimidine emerged as a model compound for development of tracer molecules for non-invasive imaging of gene expression using positron emission tomography (PET).
COBISS.SI-ID: 4698906