399043-56-2Relevant academic research and scientific papers
2-Amino-3-aroyl-4,5-alkylthiophenes: Agonist allosteric enhancers at human a1 adenosine receptors
Tranberg, C. Elisabet,Zickgraf, Andrea,Giunta, Brian N.,Luetjens, Henning,Figler, Heidi,Murphree, Lauren J.,Falke, Ruediger,Fleischer, Holger,Linden, Joel,Scammells, Peter J.,Olsson, Ray A.
, p. 382 - 389 (2007/10/03)
2-Amino-3-benzoylthiophenes are allosteric enhancers (AE) of agonist activity at the A1 adenosine receptor. The present report describes syntheses and assays of the AE activity at the human A1AR (hA1AR) of a panel of compounds consisting of nine 2-amino-3-aroylthiophenes (3a-i), eight 2-amino-3-benzoyl-4,5-dimethylthiophenes (12a-h), three 3-aroyl-2-carboxy-4,5-dimethylthiophenes (15a-c), 10 2-amino-3-benzoyl-5,6-dihydro-4H-cyclopenta[b]thiophenes (17a-j), 14 2-amino-3-benzoyl-4,5,6,7-tetrahydrobenzo[b]thiophenes (18a-n), and 15 2-amino-3-benzoyl-5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophenes (19a-o). An in vitro assay employing the A1AR agonist [125I]ABA and membranes from CHO-K1 cells stably expressing the hA1AR measured, as an index of AE activity, the ability of a candidate AE to stabilize the agonist-A1AR-G protein ternary complex. Compounds 3a-i had little or no AE activity, and compounds 12a-h had only modest activity, evidence that AE activity depended absolutely on the presence of at least a methyl group at C-4 and C-5. Compounds 17a-c lacked AE activity, suggesting the 2-amino group is essential. Polymethylene bridges linked thiophene C-4 and C-5 of compounds 17a-j, 18a-n, and 19a-o. AE activity increased with the size of the -(CH2)n- bridge, n = 3 1AR contains an allosteric binding site able to accommodate 3-aroyl substituents that are bulky and/or hydrophobic but not necessarily planar. A second region in the allosteric binding site interacts constructively with alkyl substituents at thiophene C-4 and/or C-5.
