Tautomeris m of ۶-azauracil in the gas phase and i n methano l and water clusters: A theoretical study

The s ynthesis and reactions of uracil and ۶-azauracil derivatives has been the subject of great intere st stemming mainly from their biological impo rtance and the biological activity o f aza analog ues of uracil has been intensively investigated. [۱]. Understanding the tautomeric equili brium of nucleic acid bases is fund amental as the hydroge n bond interactions of DNA and se veral modeles of mutation of DN A are based on them. ۶-Azauracil w as formerly used as an antitumour drug. For this reason a number of biochemical works have been devoted to this co mpound [۲] . In most of studies part icular emphasis was laid on the hyd ration of is olated nucleic acid bases because it was proven that explicit water molecules in their first solv ation shell have a clear influence in the electronic structur e of the solute and in the tautomeri zation proces ses. For this reason we carried out a theoretica l analysis i n which the final goal w as to establish the role of water and methanol molecules coordinated to the most suitable sites on four ۶-azauracil t automers in the lowering of the bar riers for all the possible interconv ersion proces ses between them.

کلیدواژه ها:

Tautomerization ، ۶-azauracil ، Theoretical study