Ramelteon metabolite M-II is the primary metabolite of Ramelteon and exhibits IC50 values of 208 pM and 1470 pM for human melatonin receptors (MT1 and MT2), respectively. Ramelteon itself is a selective melatonin receptor 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.
Tasimelteon-d5 is intended for use as an internal standard for the quantification of tasimelteon by GC- or LC-MS. Tasimelteon is a melatonin (MT) receptor agonist. It selectively binds MT1 and MT2 receptors over a panel of 160 additional receptors and enzymes at 10 µM. Tasimelteon inhibits forskolin-induced cAMP accumulation with EC50 values of 0.79 and 1 nM in NIH3T3 cells expressing the MT1 or MT2 receptor, respectively. Formulations containing tasimelteon have been used in the treatment of non-24-hour sleep-wake disorder.
Cyclo(L-Leu-L-Trp) is a diketopiperazine metabolite initially derived from Penicillium, exhibiting antibacterial (MICs = 125-1000 µg/ml) and antifungal activities (MICs = 8-64 µg/ml). It also demonstrates antioxidant properties by reducing the production of hydroxy radicals, as evidenced in an electron spin resonance (ESR) spectroscopy assay (IC50 = 1.8 µM). Additionally, Cyclo(L-Leu-L-Trp) has been identified as a bitter compound capable of quickly crossing rat taste cell membranes ex vivo at a 1 mM concentration. Furthermore, it acts as a melatonin receptor agonist in X. laevis melanophores, suppressing cAMP accumulation at a 20 µM concentration, with this effect being negated by the melatonin receptor antagonist luzindole.