Molecular orbital studies on nucleoside antibiotics. IV. conformation of 3'-deoxyadenosine (cordycepin) and 3'-amino-3'-deoxyadenosine

PCILO computations have been carried out on the conformation of 3'-deoxyadenosine (cordycepin) and 3'-amino-3'-deoxyadenosine. These nucleoside antibiotics results as a consequence of modification in the sugar part of adenosine. Both C(2')-endo and C(3')-endo sugar puckerings have been considered in the computations and the results obtained indicate that these nucleoside antibiotics have very similar conformational preferences as compared to those of the parent nucleoside adenosine. This similarity which is quite marked in aqueous solution has important biological significance.