title: 8-Benzamidochromen-4-one-2-carboxylic acids: potent and selective agonists for the orphan G protein-coupled receptor GPR35.
abstract: 8-Amido-chromen-4-one-2-carboxylic acid derivatives were identified as novel agonists at the G protein-coupled orphan receptor GPR35. They were characterized by a β-arrestin recruitment assay and optimized to obtain agonists with nanomolar potency for the human GPR35. The compounds were found to exhibit high selectivity versus the related GPR55. The most potent agonists were 6-bromo-8-(4-methoxybenzamido)-4-oxo-4H-chromene-2-carboxylic acid (85, EC50 12.1 nM) and 6-bromo-8-(2-chloro-4-methoxybenzamido)-4-oxo-4H-chromene-2-carboxylic acid (90, EC50 11.1 nM), both of which were >1700-fold selective versus GPR55. Most compounds were considerably less potent at rat and mouse than at human GPR35. 6-Bromo-8-(2-methoxybenzamido)-4-oxo-4H-chromene-2-carboxylic acid (87) was the only derivative that activated GPR35 of all three species at similar, low micromolar concentration. Compounds 85 and 90 are the most potent agonists at the human GPR35 known to date and might thus serve as powerful pharmacological tools to further elucidate the receptor's (patho)physiological role and its potential as a future drug target.
authors.affiliation: PharmaCenter Bonn, Pharmaceutical Institute, Pharmaceutical Chemistry I, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany.
authors.forename: Mario
authors.initials: M
authors.lastname: Funke
authors.forename: Dominik
authors.initials: D
authors.lastname: Thimm
authors.forename: Anke C
authors.initials: AC
authors.lastname: Schiedel
authors.forename: Christa E
authors.initials: CE
authors.lastname: Müller
mesh_terms: D000818:Animals; D002264:Carboxylic Acids / Q000737:chemistry* / Q000494:pharmacology*; D055598:Chemical Phenomena; D004355:Drug Stability; D006801:Humans; D006868:Hydrolysis; D008024:Ligands; D051379:Mice; D051381:Rats; D043562:Receptors, G-Protein-Coupled / Q000819:agonists*; D013045:Species Specificity; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
chemical_list: D002264:Carboxylic Acids; C111379:GPR35 protein, human; D008024:Ligands; D043562:Receptors, G-Protein-Coupled