1-Alkyl-benzotriazole-5-carboxylic Acids Are Highly Selective Agonists of the Human Orphan G-Protein-Coupled Receptor GPR109b

1-Substituted benzotriazole carboxylic acids have been identified as the first reported examples of selective small-molecule agonists of the human orphan G-protein-coupled receptor GPR109b (HM74), a low-affinity receptor for the HDL-raising drug niacin. No activity was observed at the highly homologous high-affinity niacin receptor GPR109a (HM74A). The high degree of selectivity was attributed to a difference in the amino acid sequence adjacent to a key arginine−ligand interaction allowing somewhat larger ligands to be tolerated by GPR109b.