680C91 (163239-22-3) is a potent and selective inhibitor of tryptophan 2,3-dioxygenase (TDO) Ki=42 nM).1,2Displays no activity against indoleamine 2,3-dioxygenase, MAO-A and B and does not effect serotonin uptake. Elevates CSF tryptophan by up to 260% and CSF serotonin by 170% of basal.2TDO inhibition by 680C91 in glioma cells blocked the release of kynurenine (Cat.# 10-2666), an endogenous tumor promoting AHR ligand.4
