NMR characterization of some modified nucleoside bases related to 8-nitroguanine

Abstract

It is proposed the determination of enantiomeric excess and absolute configuration of a series of enantiomeric mixtures using chiral lanthanide shift reagents. Enantiomerically pure compounds, either commercial or obtained by enantioselective synthesis will be analyzed by nuclear magnetic resonance (NMR) in the presence and absence of chiral lanthanide shift agents. Knowing the behavior of each individual enantiomers, they can be mixed, thus, it’ll be possible to verify the effect of a variety of chiral lanthanide shift in a range of enantiomeric mixtures. Most of the compounds under study have been previously analyzed by GC/HPLC, and their retention times are already known. In this case, it is possible to quantify the enantiomeric excess by GC or HPLC and use these data for further analysis by NMR using the chiral shift reagents. So, through this study it will be possible to develop a new methodology to analyze such systems by NMR, as well as, build up a library of spectra and analysis conditions for each pair of enantiomers. In summary, in the future the scientific community can use NMR in addition to the HPLC technique or even replace it. (AU)