Studies on structure of kinetin riboside and its analogues by variable-temperature NMR

Abstract Kinetin riboside and its four base-modified analogues were synthesized and their structures in solution were examined by multinuclear 1D and 2D variable-temperature NMR techniques. At lowered temperature kinetin riboside was found to exist as a mixture of two distinct conformers resulting from the restricted rotation around the C6-N 6 bond. For 8-azakinetin riboside and 2-fluorokinetin riboside the presence of two rotamers was observed at room temperature.