title: 5'-Deoxy congeners of 9-(3-amido-3-deoxy-beta-D-xylofuranosyl)-N(6)-cyclopentyladenine: new adenosine A(1) receptor antagonists and inverse agonists.
abstract: The synthesis and structure-activity relationship of N(6)-cyclopentyl-3'-substituted-xylofuranosyladenosine analogues with respect to various adenosine receptors were explored in order to identify selective and potent antagonists and inverse agonists for the adenosine A(1) receptor. In particular, the effects of removal of the 5'-OH group and introduction of selected substituents at the 3'-NH(2) position of 9-(3-amino-3-deoxy-beta-D-xylofuranosyl)-N(6)-cyclopentyladenine were probed. A solid phase-assisted synthetic approach was used to optimize the 3'-amide functionality. In view of the general concern of the presence of a 5'-OH moiety with regard to cellular toxicity, the present study describes 5'-deoxy compounds with reasonable affinity for the human adenosine A(1) receptor. Interestingly, this study shows that optimization of the 3'-"up" amide substituent can substantially compensate for the drop in affinity for the adenosine A(1) receptor, which is generally observed upon removal of the 5'-OH group. The fact that for several 3'-amido-substituted (5'-deoxy)-N(6)-cyclopentyladenosine derivatives, guanosine 5'-triphosphate-induced shifts in K(i) values were significantly lower than 1 implies that these analogues behave as inverse agonists. This is further supported by their 1,3-dipropyl-8-cyclopentylxanthine-like capacity to increase forskolin-induced adenosine cyclic 3',5'-phosphate production.
authors.affiliation: Laboratory for Medicinal Chemistry (FFW), Ghent University, Harelbekestraat 72, 9000 Gent, Belgium. serge.vancalenbergh@rug.ac.be
authors.forename: Serge
authors.initials: S
authors.lastname: Van Calenbergh
authors.forename: Andreas
authors.initials: A
authors.lastname: Link
authors.forename: Shelly
authors.initials: S
authors.lastname: Fujikawa
authors.forename: Rianne A F
authors.initials: RA
authors.lastname: de Ligt
authors.forename: Veerle
authors.initials: V
authors.lastname: Vanheusden
authors.forename: Abolfasl
authors.initials: A
authors.lastname: Golisade
authors.forename: Norbert M
authors.initials: NM
authors.lastname: Blaton
authors.forename: Jef
authors.initials: J
authors.lastname: Rozenski
authors.forename: Adriaan P
authors.initials: AP
authors.lastname: IJzerman
authors.forename: Piet
authors.initials: P
authors.lastname: Herdewijn
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D016466:CHO Cells; D006224:Cricetinae; D018360:Crystallography, X-Ray; D000242:Cyclic AMP / Q000096:biosynthesis; D003839:Deoxyadenosines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D008958:Models, Molecular; D058906:Purinergic P1 Receptor Agonists; D058915:Purinergic P1 Receptor Antagonists; D011869:Radioligand Assay; D051381:Rats; D018047:Receptors, Purinergic P1 / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D003839:Deoxyadenosines; D058906:Purinergic P1 Receptor Agonists; D058915:Purinergic P1 Receptor Antagonists; D018047:Receptors, Purinergic P1; D000242:Cyclic AMP