Isolation and Characterization of an Unusual Nucleoside, 1-α-D-Ribofuranosyl-4-pyridone-3-carboxamide, from the Urines of Normal Human Individuals and Leukemic Patients

A novel modified nucleoside, 1-α-D-Ribofuranosyl-4-pyridone-3-carboxamide, has been isolated from the urines of one normal human individual and two CML patients. The structure was assigned on the basis of UV, NMR and mass spectral data and confirmed by comparison with an authentic sample synthesized in our laboratory. This constitutes the first example of the occurrence of a nucleoside with an α-riboside linkage in human urine.