Synthesis AND Adenosine Receptor Affinity of 7-β-D-Ribofuranosylxanthine

Abstract

7-β-D-Ribofuranosylxanthine, a previously unreported isomer of xanthosine, was prepared in four steps from 7-benzylxanthine. The procedure, which involves the use of pivaloyloxymethyl groups to protect the xanthine ring, was also applied to preparation of some 1-N-alkyl derivatives of 7-ribosylxanthine. Adenosine receptor affinity for these compounds was determined. 7-β-D-Ribofuranosylxanthine was found to have higher affinity and greater selectivity for the A₁ receptor than previously reported xanthine nucleosides, and to be a partial agonist.