title: Linear and proximal benzo-separated alkylated xanthines as adenosine-receptor antagonists.
abstract: The linear and proximal benzo-separated derivatives of 8-phenyltheophylline, 1,3-diethyl-8-phenylxanthine, 1,3-dipropylxanthine, 1,3-dibutylxanthine, 3-isobutyl-1-methylxanthine, theophylline, caffeine, and isocaffeine have been synthesized and evaluated for affinity at the A1 and A2 adenosine receptors. Although structure-activity relationships in the benzo-separated series differed from the relationships in the simple xanthines, the most potent of the benzo-separated xanthines were about equal in affinity to the most potent of the corresponding xanthines. On the basis of the present results and the diverse structures reported in the literature as non-xanthine adenosine antagonists, it appears that the primary requirement for adenosine-receptor affinity in nonnucleosides is a flat, neutral, fused-ring heterocycle and that once this requirement is met there are numerous potential binding modes.
authors: Department of Chemistry, University of South Florida, Tampa 33620-5250.
authors: S W
authors: SW
authors: Schneller
authors: A C
authors: AC
authors: Ibay
authors: W J
authors: WJ
authors: Christ
authors: R F
authors: RF
authors: Bruns
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D051381:Rats; D011983:Receptors, Purinergic / Q000187:drug effects* / Q000378:metabolism; D013329:Structure-Activity Relationship; D014970:Xanthines / Q000138:chemical synthesis* / Q000494:pharmacology
chemical_list: D007202:Indicators and Reagents; D011983:Receptors, Purinergic; D014970:Xanthines