ML-109 is a potent and full thyroid stimulating hormone receptor (TSHR) agonist, with an EC50 of 40 nM.
ML-109 (Compound 2) is a full agonist at TSHR with an EC50 of 40 nM and, like compound 1, it has no activity at FSHR or LHCGR. ML-109 contains an aminal, a functional group that is subject to hydrolysis and/or other degradation mechanisms. ML-109 is surprisingly stable at neutral and basic conditions (t1/2 of ~16 h) but is found to degrade at low pH (t1/2 of ~3 h)[1].
[1]. Neumann S, et al. Small-molecule agonists for the thyrotropin receptor stimulate thyroid function in human thyrocytes and mice. Proc Natl Acad Sci U S A. 2009 Jul 28;106(30):12471-6.