On the influence of conformational locking of sugar moieties on the absorption and circular dichroism of nucleosides from synchrotron radiation experiments

Absorption and synchrotron radiation circular dichroism (SRCD) spectra of nucleosides and locked nucleosides containing either the adenine and thymine nucleobase were measured in the ultraviolet and vacuum ultraviolet (down to 176 nm) regions. The CD spectra strongly depend on the chemical structure of the sugar and the introduction of a methylene bridge that locks it into a specific conformation. Spectra of compounds with different configurations at the sugar atoms shed light on what determines the sign and intensity of the CD bands.