3'-AMIDATED 3'-DEOXYXYLOFURANOSE ANALOGS OF N-6-CYCLOPENTYLADENOSINES- A NEW CLASS OF NONXANTHINE ANTAGONISTS AT THE ADENOSINE A(1) RECEPTOR

Full adenosine A(1) receptor agonists like CPA and other N-6-substitut ed adenosine analogs have previously been shown to become partial agon ists upon deletion of the 3'-hydroxyl moiety. The present study furthe r explored the C-3' site for modification. The modest affinity at A(1) and A(2a) receptors found in the 3'-amido-3'-deoxyxylofuranosyladenin e series prompted us to synthesize the corresponding N-6-cyclopentyl d erivatives, which proved to exhibit potent antagonistic behaviour at t he A(1) receptors. This represents a new perspective in the purinergic field.