C-nucleoside analogues of furanfurin as ligands to A(1) adenosine receptors

Furanfurin (2-beta-D-ribofuranosylfuran-4-carboxamide) derivatives and anal ogues were synthesized and their affinity for adenosine receptors was deter mined. The agonistic behavior of furanfurin against A(1) receptors is prese rved only when the furan ring is substituted with isosteric pentatomic ring systems such as oxazole, thiazole or thiophene, and the carboxamide group is unsubstituted. Replacement of the hydrogen atoms of the carboxamide grou p with alkyl, cycloalkyl or arylalkyl groups generates compounds endowed wi th moderate antagonistic activity. (C) 2000 Elsevier Science Ltd. All right s reserved.