Theoretical Study on the Relative Energies of Anionic Pterin Tautomers

Abstract

Pterins exist as several tautomeric forms and behave as weak acids in aqueous solutions. Therefore, several acidbase equilibria may be present. For several pterin derivatives, the range of the experimental pKa lies in the range 6-8. The anionic form of the lactam structure is the only structure considered in the literature to represent the chemistry of pterins in alkaline solution. In the present study, density functional theory calculations were used to determine the relative energies of various anionic tautomers of pterin present in aqueous solution which may play a role in chemical and biological systems.

Keywords

• pterin
• tautomer
• energy