Structure-activity relationship study of pyridazine derivatives as glutamate transporter EAAT2 activators

Excitatory amino acid transporter 2 (EAAT2) is the major glutamate transporter and functions to remove glutamate from synapses. A thiopyridazine derivative has been found to increase EAAT2 protein levels in astrocytes. A structure-activity relationship study revealed that several components of the molecule were required for activity, such as the thioether and pyridazine. Modification of the benzylthioether resulted in several derivatives (7-13, 7-15 and 7-17) that enhanced EAAT2 levels by >6-fold at concentrations <5 mu M after 24 h. In addition, one of the derivatives (7-22) enhanced EAAT2 levels 3.5-3.9-fold after 24 h with an EC50 of 0.5 mu M. (C) 2011 Elsevier Ltd. All rights reserved.