Far UV synchrotron radiation circular dichroism of guanine nucleosides

Synchrotron radiation circular dichroism spectra of 2'-deoxyribonucleosides, as well as a few guanine nucleosides were recorded between 170-330 nm. The CD profile of each nucleoside is unique, and there is a general similarity in the SRCD patterns of deoxyribonucleosides and those recorded by a benchtop CD as previously reported. Furthermore, the locked nucleic acid derivative of guanine nucleoside (LNA-G) showed opposite CD profiles to the rest of the guanine nucleoside derivatives. The conformational parameters of the nucleosides were analyzed against the crystal structures available in the Cambridge Crystallographic Data Center. The pseudorotational phase angles of the guanine nucleoside derivatives in solution were also determined based on NMR coupling constants. Analyses showed no apparent correlation between pseudorotational phase angles and CD patterns.