PROTON MAGNETIC RESONANCE SPECTRA OF ADENINE 5'-NUCLEOTIDES . ASSIGNMENT OF H2' H3' AND H4' RESONANCE BANDS ANT THEIR STRUCTURAL IMPLICATIONS

Proton magnetic resonance spectra (100 MHz) of adenosine 5′-monophosphate (5′-AMP) and adenosine 5′-triphosphate (5′-ATP) in which all the nonexchanging proton peaks are separate have been obtained. The H2’, H3’, and H4’ bands were identified by comparison of the 5′-AMP spectrum with the spectra of 2′-AMP and 3′-AMP. The H2’ assignment was verified by a double resonance experiment. The chemical shifts of these three protons and the J1′-2’, 2′-3’, and J3′-4’ coupling constants in 5′-AMP and 5′-ATP have been calculated assuming no coupling between nonvicinal protons. Comparison of chemical shifts in various adenine nucleotides have furnished additional information concerning structure and stacking of 5′-AMP and 5′-ATP in D2O solution, particularly with regard to the torsion angle about the glycosidic bond and the rotational freedom of the phosphate group. © 1968, American Chemical Society. All rights reserved.