An isodesmic comparison of the C1 modified reduced pteridine ring as a folic acid model

Tetrahydrofolate or pteroyl glutamate (H4PteGlu) functions as a single carbon (C1) carrier and a cofactor for intracellular reactions. The reduced pteridine ring of H4PteGlu was used as a model for the six C1 substituted forms and the unsubstituted form of H4PteGlu. An isodesmic reaction was performed using ab initio molecular orbital calculations at the Restricted Hartree–Fock 3-21G level of theory. The isodesmic reaction allows for further characterization of the relationships between the C1 units beyond the biochemical and provides the foundation for further analysis