Ab initio vibrational calculations on ara-T molecule: application to analysis of IR and Raman spectra.
The FTIR and FT-Raman spectra are reported for the arabinonucleoside ara-T (1-beta-D-arabinofuranosylthymine), which shows antiviral activity. The accurate knowledge of the vibrational modes is a prerequisite for the elucidation of drug-nucleotide and drug-enzyme interactions. The FTIR and FT-Raman spectra of ara-T were recorded from 4000 to 30 cm(-1). A tetradeuterated derivative (deuteration at N3, and hydroxyl groups O'2, O'3, and O'5) was synthesized and the observed isotopic shifts in its spectra were used for the vibrational analysis of ara-T. The theoretical frequencies and the potential energy distribution (PED) of the vibrational modes of ara-T were calculated using the ab initio Hartree-Fock/3-21G method. An assignment of the vibrational spectra of ara-T is proposed considering the scaled PED and the observed band shifts under deuteration. The scaled ab initio frequencies were in reasonable agreement with the experimental data.
Hernández
B
B
Departamento de Ciencias y Técnicas Fisicoquímicas, Universidad Nacional de Educación a Distancia (UNED), Senda del Rey s/n, E-28040 Madrid, Spain.
Navarro
R
R
Vergoten
G
G
Hernanz
A
A
D000998:Antiviral Agents / Q000737:chemistry; D001087:Arabinonucleosides / Q000737:chemistry*; D008958:Models, Molecular; D013055:Spectrophotometry, Infrared; D013059:Spectrum Analysis, Raman; D013936:Thymidine / Q000031:analogs & derivatives* / Q000737:chemistry*
D000998:Antiviral Agents; D001087:Arabinonucleosides; C010032:thymine arabinoside; D013936:Thymidine