Melatonin

Melatonin (N-acetyl-5-methoxytryptamine) is a naturally occurring indoleamine hormone synthesised in the pineal gland from L-tryptophan via serotonin. Two sequential enzymatic steps produce it: arylalkylamine N-acetyltransferase (AANAT) converts serotonin to N-acetylserotonin, which hydroxyindole-O-methyltransferase (HIOMT) methylates to produce melatonin. It is studied in laboratory settings for MT1 and MT2 receptor pharmacology, circadian rhythm regulation, direct antioxidant signalling, and immune modulation research.

Molecular formula: C13H16N2O2 | Molecular weight: 232.28 g/mol | CAS: 73-31-4 | Chemical name: N-acetyl-5-methoxytryptamine | Class: Indoleamine hormone | Purity: greater than or equal to 98% as verified by HPLC | Form: Lyophilised powder | Appearance: White crystalline powder | Storage: -20°C desiccated, protected from light

MT1 (MTNR1A) and MT2 (MTNR1B) are Gi-coupled GPCRs expressed in the suprachiasmatic nucleus (SCN), retina, and peripheral tissues. MT1 activation reduces SCN neuronal firing rate and influences circadian phase; MT2 mediates phase shifting at different circadian time windows and has been examined in retinal physiology and glucose metabolism. MT2 variants have been studied in the context of type 2 diabetes susceptibility in genetic research.

Beyond receptor-mediated effects, melatonin functions as a direct free radical scavenger through electron transfer reactions, generating AFMK and AMK metabolites also studied for antioxidant activity. Its lipophilic structure enables passage across all biological membranes including the inner mitochondrial membrane — relevant to mitochondrial oxidative stress research alongside SS-31 and MOTS-c. Note: limited direct aqueous solubility; use DMSO or ethanol for stock preparation.

For laboratory and analytical research purposes only. Not for human or veterinary use.