TG6-10-1 is an EP2 antagonist, shows low-nanomolar antagonist activity against only EP2, >300-fold selectivity over human EP3, EP4, and IP receptors, 100-fold selectivity over EP1 receptors. IC50 value: 7.5 uMTarget: serotonin 5-HT2B receptorin vitro: TG6-10-1, an analog of TG4-155 (a prostaglandin receptor EP2 antagonist, with a relatively short plasma half-life (0.6 h) and low brain:plasma ratio (0.3) after systemic administration in mice), which has a superior pharmacokinetic profile making it suitable for more extensive testing. TG6-10-1 had negligible effect on a panel of 40 enzymes, ion channels, receptors, and neurotransmitter transporters (IC50s >10 uM), except that TG6-10-1 weakly inhibited the serotonin 5-hydroxytryptamine 2B (5-HT2B) receptor with IC50 = 7.5 uM. At a high concentration (10 uM), TG6-10-1 had little or no effect on the enzymatic activity of COX-1 (7% inhibition) and COX-2 (14% inhibition), and inhibited the leukotriene B4 (LTB4) receptor BLT1 by 1% .EP2 receptor activation by PGE2 stimulates adenylate cyclase to elevate cytoplasmic cAMP level. TG6-10-1 has a competitive mechanism of antagonism of the EP2 receptor with an equilibrium dissociation constant for the antagonist-receptor complex (KB) of 17.8 nM.in vivo: TG6-10-1 displayed a plasma half-life of 1.6 h and a brain:plasma ratio of 1.6 after systemic administration (5 mg/kg, i.p.) in mice. A significant increase in survival was observed in post-SE mice that received TG6-10-1 compared with those in the vehicle group. Administration of TG6-10-1 improved 1-wk survival from 60 to 90% after SE.

References:
[1]. Jiang J, et al. Inhibition of the prostaglandin receptor EP2 following status epilepticus reduces delayed mortality and brain inflammation. Proc Natl Acad Sci U S A. 2013 Feb 26;110(9):3591-3596.