Comparison of theoretical and experimental approaches to determination of conformation of nucleosides about the glycosidic bond

摘要: Abstract A study has been made by means of 1H-NMR spectroscopy the syn anti dynamic equilibrium about glycosidic bond for 5′-deoxyadenosine and some 8-substituted analogues, in different solvents. The results are compared with those previously obtained parent adenosine its analogues. Quantum chemical calculations, aid Classical Potential PCILO procedures, were applied to obtain energies conformations base 5′-deoxyadenosine, their 8-methyl 8-halogeno derivatives. Good agreement was found between experimentally determined solution corresponding theoretically energy minima, particularly calculated method. Comparison quantitative experimental data theoretical used evaluate validity latter applicability studies nucleoside conformation. findings pointed existence a marked flexibility nucleosides when 8-substituents not too bulky, such as methyl or bromine. Considerations is given possible correlations conformational parameters 5′-deoxy It shown that proposed stabilization conformation intramolecular hydrogen bonding, 5′-OH…N(3), accord present study.