Low-frequency vibrational spectra of crystalline uracil, thymine and their 1-methyl-derivatives

Elucidating collision induced dissociation products and reaction mechanisms of protonated uracil by coupling chemical dynamics simulations with tandem mass spectrometry experiments

“…The diketo form of uracil is reported to be the predominant isomer in condensed phase . In the gas phase, O7 and O8 proton affinities become close in energy, and so we find that tautomerization and PT are more plausible .…”

“…The diketo form of uracil is reported to be the predominant isomer in condensed phase. [46][47][48][49][50] In the gas phase, O7 and O8 proton affinities become close in energy, [51][52][53][54] and so we find that tautomerization and PT are more plausible. [15] The relative energies of the different tautomers studied in the present work are summarized in Table 1, where we also report the corresponding Boltzmann population at 300 K. It is worth noting that the global minimum, isomer 1, cannot be generated directly from protonation of the diketo form of uracil.…”

Comparison of the Hydrogen Bond Interaction Dynamics in the Guanine and Cytosine Crystals: Ab Initio Molecular Dynamics and Spectroscopic Study

“…DNA can undergo structural changes, sometimes leading to mutations, because of a variety of environmental factors which can either be chemical or physical in nature. − It should be stressed that some chemical factors include interaction with small molecules or enzymes leading to uncoiling of DNA or breaking of hydrogen bonds (HBs). , From this point of view, the HBs are the most important interactions in nature. The HBs build the structure of DNA by means of a lock and key mechanism. − Only complementary nucleobases may build up the DNA structure.…”

FTIR and FT-Raman spectra of 5-methyluracil (thymine)

“…Uracil and its derivatives, constituents of the genetic material, play a fundamental role in basic biological processes. 12,13 The assignments of the bands observed in the spectra have been mainly based on a normal coordinate analysis of the ab initio values at the HF/6-31G Ł or 6-31G ŁŁ levels, together with a comparison with the assigned spectrum of uracil. 1 -8 The monomer spectra are complicated by several phenomena; coupling between the C2 O, C4 O and C C stretching modes; Fermi resonance; coupling between ring stretching, N-H and C-H deformation modes; imperfect isolation; and interaction with H 2 O or N 2 impurities in the matrix.…”