Abstract
The IR spectra of crystalline cytidine (Cyd), ethenocytidine (epsilon Cyd), and their hydrochlorides (Cyd-Hcl and epsilon CyD-HCl) have been analyzed to determine the spectroscopic manifestations of the structural differences that were previously established for these nucleosides from X-ray studies. O,N-Deuteration of the samples turned out to be a successful approach to obtaining interpretable spectra. The analysis was carried out in three frequency ranges: (i) The 2600-1900 cm-1 range originating from the vO-D and VN-D vibrations. All intermolecular hydrogen bonds could be recognized here. The positions of the individual vO-D (vN-D) bands were correlated with the geometrical delta HB parameters presenting the strengths of hydrogen bonds in which these groups act as donors (ii) The 1750-1500 cm-1 region originating from the stretching vibrations of double bonds. All absorption bands in this region were interpreted in terms of electronic structures of the base fragments. (iii) The region of the C-H stretching vibrations of the base fragments (3200-3000 cm-1) and sugar moieties (3000-2800 cm-1). The Csp2-H vibrations also reflect the electronic structures of the base fragments, whereas the vCsp-H frequencies seem to be sensitive to etheno-bridging and to the presence of an intramolecular C6-H...05' hydrogen bond.
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- Barrio J. R., Sattsangi P. D., Gruber B. A., Dammann L. G., Leonard N. J. Species responsible for the fluorescence of 3,N4-ethenocytidine. J Am Chem Soc. 1976 Nov 10;98(23):7408–7414. doi: 10.1021/ja00439a049. [DOI] [PubMed] [Google Scholar]
- Jaskólski M., Krzyzosiak W., Sierzputowska-Gracz H., Wiewiórowski M. Comparative structural analysis of cytidine, ethenocytidine, and their protonated salts. I. Crystal and molecular structure of ethenocytidine. Nucleic Acids Res. 1981 Oct 24;9(20):5423–5442. doi: 10.1093/nar/9.20.5423. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shapiro R., Klein R. S. Reactions of cytosine derivatives with acidic buffer solutions. II. Studies on transamination, deamination, and deuterium exchange. Biochemistry. 1967 Nov;6(11):3576–3582. doi: 10.1021/bi00863a032. [DOI] [PubMed] [Google Scholar]
- TSUBOI M., KYOGOKU Y., SHIMANOUCHI T. Infrared absorption spectra of protonated and deprotonated nucleosides. Biochim Biophys Acta. 1962 Jan 22;55:1–12. doi: 10.1016/0006-3002(62)90925-3. [DOI] [PubMed] [Google Scholar]