Identification and Synthesis Of 5′-Deoxyxanthosine, a Novel Nucleoside in Normal Human Urine1

Methods used in the identification and synthesis of 5′-deoxyxanthosine (5′-dX), a novel nucleoside found in normal human urine, are described. The urine sample was separated into nucleoside components by HPLC. Low and high resolution GC/MS techniques were then used to assign a tentative structure of the new nucleoside as 5′-dX. Finally, after biochemical synthesis, a comparison of the reference material with the urinary sample using mass spectrometry confirmed the structure as 5′-dX.