CONFORMATIONAL STUDIES ON ANTI-AIDS DRUGS

Nucleosides which lack 2- and 3'-hydroxyl groups have been shown to be active against human immunodeficiency virus (HIV) and some of these a nti-AIDS agents are: 2'-3'-dideoxyadenosine (ddA), 2'-3'-dideoxyinosin e (ddI), 2'-3'-dideoxycytidine (ddC), 2'-3'-dideoxythymidine (ddT) and 2'-3'-dideoxyguanosine (ddG). Quantum mechanical PCILO investigations have been carried out on two of these molecules, namely, ddA and ddI having both C2-endo and C3'-endo sugar puckers as well as on their res pective parent nucleosides. The results indicate a remarkable similari ty in the conformational profiles of these anti-AIDS agents and the pa rent nucleosides. The biological significance of this result has been analysed in the light of our results on the conformation of azidothymi dine (AZT) which is the most potent anti-AIDS drug.