Specific interactions of deprotonated carboxylic group with uracil and thymine provoke diketo-->keto-enol tautomeric transition in bases.
The 1H NMR and MNDO/H calculation data combined indicate the uracil and thymine tautomeric transitions from the ground diketo tautomeric state to the high-energy keto-enol one stimulated by specific interaction with carboxylate ion in anhydrous DMSO, which is blocked by base methylation at the 1 or 3 positions.
Samijlenko
S P
SP
Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv.
Kondratyuk
I V
IV
Potyahaylo
A L
AL
Stepanyugin
A V
AV
Hovorun
D M
DM
D002264:Carboxylic Acids / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013816:Thermodynamics; D013941:Thymine / Q000737:chemistry*; D014498:Uracil / Q000737:chemistry*
D002264:Carboxylic Acids; D014498:Uracil; D013941:Thymine