3-Unsubstituted xanthine derivatives bearing a cyclopentyl or a phenyl residue in the 8- position were synthesized and developed as A2B adenosine receptor antagonists. Compounds bearing polar substituents were prepared to obtain water-soluble derivatives. 1- Alkyl-8-phenylxanthine derivatives were found to exhibit high affinity for A2B adenosine receptors (ARs). 1, 8-Disubstituted xanthine derivatives were equipotent to or more potent ...
