Nucleoside conformations. XVII. A PMR study of 2'-anhydronucleosides and comparison with X-ray data.
A series of 2'-cyclo-nucleosides (2,2'-O-anhydro-uridine, -N(3)-uridine and cytidine and 8,2'-S-anhydro-guanosine) have been studied by PMR in DMSO and D(2)O. As expected these compounds are quite rigid, but their solution conformation is considerably different from that observed in single crystal x-ray studies. While the pyrimidine cyclonucleosides in the crystal form show a C(4')-endo conformation (pseudorotational phase angle P=212 degrees to 233 degrees ), their solution conformation is C(1')-exo (P=130 degrees to 138 degrees ) and the cyclothioguanosine shows a closely similar one (P=112 degrees ). Exocyclic rotamer distribution is different in the various compounds.
Guschlbauer
W
W
Son
T D
TD
Blandin
M
M
Catlin
J C
JC
D018360:Crystallography, X-Ray; D009682:Magnetic Resonance Spectroscopy; D009690:Nucleic Acid Conformation; D009705:Nucleosides / Q000737:chemistry*; D009712:Nucleotides, Cyclic / Q000737:chemistry; D013816:Thermodynamics
D009705:Nucleosides; D009712:Nucleotides, Cyclic