Molecular orbital studies on nucleoside antibiotics, VII. Conformation of 2′-amino- 2′-deoxyguanosine

Abstract

Conformational properties of the nucleoside antibiotic 2′-amino-2′-deoxyguanosine have been investigated by the PCILO method along with those of its parent nucleoside, guanosine. This antibiotic, formed by replacement of the 2′-hydroxyl group by an amino group in guanosine, shows anti-tumor activity and also inhibits RNA and protein syntheses. Both C(2′)-endo and C(3′)-endo sugar conformations have been considered in the computations. The results indicate striking similarity between the conformations of the antibiotic and the parent nucleoside, particularly in simulated aqueous environment. The biological implication of this result in terms of the antibiotic activity is discussed.