FTIR Study on Nucleotide Analogues. 1. Spectral Characterization of Dinucleoside Methylphosphonates and Dinucleoside 5′- Methylenephosphonates in Solution and in Solid Phase

Abstract

Some conformational feature of dithymidine nucleotides containing natural 3′→5′ phosphodiester, methylphosphonate, or 5′–methylenephosphonate internucleotidic linkages were probed in solution and in solid phase using FTIR spectroscopy. A high similarity of the IR spectra in the region of 1800–1250 cm⁻¹ indicates that all the investigated compounds have similar glycosidic torsion angels and the preferred conformation of the deoxyribose rings. However, small but significant differences between the R_p and S_P diastereomers of methylphosphonate analogue 5 may suggest that the association or the hydration mode of these compounds may vary.