title: Effects of conformational restriction of 2-amino-3-benzoylthiophenes on A(1) adenosine receptor modulation.
abstract: 2-Amino-3-benzoylthiophenes (2A3BTs) have been widely reported to act as allosteric enhancers (AEs) at the A(1) adenosine receptor (A(1)AR). Herein we describe the synthesis of a series of 1-aminoindeno[1,2-c]thiophen-8-ones and a series of (2-aminoindeno[2,1-b]thiophen-3-yl)(phenyl)methanones as conformationally rigid analogues of the 2A3BTs. These compounds were screened using a functional assay of A(1)AR-mediated phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) in intact Chinese hamster ovary (CHO) cells to identify both potential agonistic effects as well as the ability to allosterically modulate the activity of the orthosteric agonist, N(6)-(R-phenylisopropyl)adenosine (R-PIA). All of the 1-aminoindeno[1,2-c]thiophen-8-ones (14a-c and 17a-f) proved either to be inactive or behaved as antagonists in the functional assay. However, the (2-aminoindeno[2,1-b]thiophen-3-yl)(phenyl)methanones with para-chloro substitution (compounds 25b, 25d, and 25f) did significantly augment the R-PIA response, indicating a positive allosteric effect.
authors.affiliation: Medicinal Chemistry and Drug Action. Monash Institute of PharmaceuticalSciences, Monash University, 381 Royal Parade, Parkville VIC 3052, Australia.
authors.forename: Luigi
authors.initials: L
authors.lastname: Aurelio
authors.forename: Celine
authors.initials: C
authors.lastname: Valant
authors.forename: Bernard L
authors.initials: BL
authors.lastname: Flynn
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Sexton
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: White
authors.forename: Arthur
authors.initials: A
authors.lastname: Christopoulos
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Scammells
mesh_terms: D058907:Adenosine A1 Receptor Agonists; D058916:Adenosine A1 Receptor Antagonists; D000494:Allosteric Regulation; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D018360:Crystallography, X-Ray; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D008968:Molecular Conformation; D010766:Phosphorylation; D013329:Structure-Activity Relationship; D013876:Thiophenes / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology
chemical_list: D058907:Adenosine A1 Receptor Agonists; D058916:Adenosine A1 Receptor Antagonists; D013876:Thiophenes; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3