ChEBI: Melatonin is a member of the class of acetamides that is acetamide in which one of the hydrogens attached to the nitrogen atom is replaced by a 2-(5-methoxy-1H-indol-3-yl)ethyl group. It is a hormone secreted by the pineal gland in humans. It has a role as a hormone, an anticonvulsant, an immunological adjuvant, a radical scavenger, a central nervous system depressant, a human metabolite and a mouse metabolite. It is a member of acetamides and a member of tryptamines. It derives from a tryptamine.NCI Thesaurus (NCIt): Therapeutic Melatonin is a therapeutic chemically synthesized form of the pineal indole melatonin with antioxidant properties. The pineal synthesis and secretion of melatonin, a serotonin-derived neurohormone, is dependent on beta-adrenergic receptor function. Melatonin is involved in numerous biological functions including circadian rhythm, sleep, the stress response, aging, and immunity.