Ramelteon metabolite M-II is the primary metabolite of Ramelteon and exhibits IC50 values of 208 pM and 1470 pM for human melatoninreceptors (MT1 and MT2), respectively. Ramelteon itself is a selective melatoninreceptor agonist.
TIK-301 is a chlorinated melatonin derivative and a potent, high-affinity, and orally active melatonin MT1 and MT2 receptors agonist (Kis: 0.081 nM and 0.042 nM, respectively). TIK-301 is also a 5-HT2B 5-HT2C receptor antagonist with antidepressant action. TIK-301 has the potential for sleep disorders and other circadian rhythm disorders treatment.