Interactions of cytidine with N~2-functionalized guanosines and cytidine-cytidine exchange involving a GC pair - NMR and fluorescence spectroscopic study

摘要

Two N~2-functionalized guanosines by diphenylaminobiphenyl and di(2-pyridyl)aminobiphenyl have been found to act as the effective probes for G-C interactions in organic media. Because of the highly emissive nature of the N~2-functionalized guanosines in the visible region, the GC base pair formation event accompanied by distinct fluorescence quenching can be readily monitored by fluorescence spectroscopy. NMR and fluorescence results confirm that the N~2-arylguanosines form H-bonded pairs with cytidine, selectively. An unusual exchange pathway between non-bound cytidine and bound cytidine, in the GC pair, has been identified and extensively studied by NMR methods.