• A2B
• adenosine receptor

Adenosine is an endogenous purine nucleoside ,which have a very important role in many physiological functions through interaction with specific cell-surface-G-protein-coupled receptors , which are classified into four subtypes, namely A1, A2A, A2B and A3 Adenosine Receptors (ARs). A2B ARs have been generally defined as the “low affinity ARs”, due to their low affinity for the endogenous ligand and for other typical agonist (i.e.: NECA, R-PIA), in contrast with other AR subtypes. A2B AR activation implies stimulation of adenylate cyclase and activation of phospholipase C through coupling to Gs and Gq/11 proteins, producing an increase in intracellular cAMP and calcium ions levels. This receptor is expressed in the gastrointestinal tract, bladder, lung, mast cells, eye, adipose tissue, brain, kidney, liver and other tissues. Physiological and pathological process mediated by A2B AR include inflammation, angiogenesis induction, glucose metabolism and the grow and the development of some tumours. For the above A2B AR have been investigated in recent years as potential target for the treatment of numerous pathologies. In afford to identify novel ligands possesses high affinity and selectivity for A2B subtypes, my research group have design the new 3-ketoindole derivatives. This compounds can be regarded as open chain analogues of the triazinobenzimidazones recently described as A2B AR antagonist. In this thesis I describe the synthesis and the biological evolution of the 3-ketoindoles on A1, A2A, A2B and A3 ARs.