Conformational Studies of Novel Antiretroviral Analogs of Zidovudine.

BAUMGARTNER, M.T.; MOTURA, M.I.; CONTRERAS, R.H.; PIERINI, A.B.; BRIÑON,M.C.

Marcel Dekker

Lugar: N.Y.; Año: 2003 vol. 22 p. 45 - 45

onformational properties of three novel zidovudine analogs, namely 30-azido-30- deoxy-50-O-isonicotinoylthymidine (AZT-Iso, 2), ()-trans-(5S,6S)-5-bromo-6, 50-epoxy-5,6-dihydro-30-azido-30-deoxythymidine (3) and (þ)-trans-(5R,6R)-5- bromo-6,50-epoxy-5,6-dihydro-30-azido-30-deoxythymidine (4), have been investigated by AM1 calculations and NMR studies, and compared with those of the parent nucleoside (AZT, 1). Based on the results obtained the following correlation may be established, a) AZT and AZT-Iso exhibit a conformational behavior analog to other pyrimidinic nucleosides, displaying a dynamic equilibrium in solution where the two conformers (North and South) undergo a constant transformation. b) Compounds 3 and 4 show a different conformational profile. The estimate of the pseudorotation phase angle reveals the rigid structures of the latter compounds, which do not evidence conformational equilibrium in solution;the azide group being the only group free to rotate. c) Di