M5250 Sigma-Aldrich


powder, ≥98% (TLC)

Synonym: N-Acetyl-5-methoxytryptamine

  • CAS Number 73-31-4

  • Empirical Formula (Hill Notation) C13H16N2O2

  • Molecular Weight 232.28

  •  Beilstein/REAXYS Number 205542

  •  EC Number 200-797-7

  •  MDL number MFCD00005655

  •  PubChem Substance ID 24278103

  •  NACRES NA.32



Related Categories Alkaloid, Antitumor Agents, Application Index, Biochemicals and Reagents, Cancer Research,
Quality Level   200
biological source   synthetic (organic)
assay   ≥98% (TLC)
form   powder
color   white to off-white
mp   116.5-118 °C (lit.)
solubility   ethanol: 50 mg/mL
storage temp.   −20°C
SMILES string   COc1ccc2[nH]cc(CCNC(C)=O)c2c1
InChI   1S/C13H16N2O2/c1-9(16)14-6-5-10-8-15-13-4-3-11(17-2)7-12(10)13/h3-4,7-8,15H,5-6H2,1-2H3,(H,14,16)
Gene Information   human ... MTNR1A(4543), MTNR1B(4544), NOS1(4842), NOS2(4843), NOS2B(201288), NOS2C(645740), NOS3(4846)


General description

Melatonin (N-acetyl-5-methoxytryptamine) is synthesized from an essential amino acid tryptophan. It is a pineal gland neurohormone. Direct, non-receptor-mediated free radical scavenging activity induced by melatonin, makes it unique from other classic hormones. Melatonin is expressed in variety of organisms such as bacteria, algae, fungi, plants, insects, and vertebrates including humans.


Melatonin has been administered to experimental animals for following studies:
• To determine if long-term melatonin administration is able to induce reproductive changes and how melatonin exerts its protective action related to lipid oxidation and antioxidant activities in the rat ovary during ovulation.
• To determine the effect of melatonin on endoplasmic reticulum stress and sirtuin 1 expression in neuronal cells of newborn rats after hypoxia–ischemia.
• To study the effect of melatonin on chronic stress-induced gut dysfunction in stressed mice.


1, 5, 10 g in glass bottle

250 mg in glass bottle

Biochem/physiol Actions

Hormone; mediates photoperiodicity in mammals; inhibits cerebellar nitric oxide synthetase; peroxynitrite scavenger. Melatonin has complex effects on apoptotic pathways, inhibiting apoptosis in immune cells and neurons but enhancing apoptotic cell death of cancer cells. Inhibits proliferation/metastasis of breast cancer cells by inhibiting estrogen receptor action.

Melatonin is characterized with variety of properties such as antioxidant, autocoid, paracoid and hormonal properties, as well as anti- inflammatory and anti-apoptotic properties. Melatonin is implicated in the regulation of seasonal reproduction, energy metabolism and thermoregulation in mammals. Melatonin plays a vital role in the lessening of neonatal hypoxia–ischemia (HI) induced endoplasmic reticulum (ER) stress and conserves sirtuin 1( SIRT-1) expression.

Features and Benefits

This compound is also offered as part of Sigma′s Library of Pharmacologically Active Compounds (LOPAC®1280), a biologically annotated collection of high-quality, ready-to-screen compounds. Click here to learn more.


Solutions are light sensitive and subject to oxidation.

Other Notes

Tandem Mass Spectrometry data independently generated by Scripps Center for Metabolomics is available to view or download in PDF. M5250.pdf Tested metabolites are featured on Scripps Center for Metabolomics METLIN Metabolite Database. To learn more, visit

Legal Information

LOPAC is a registered trademark of Sigma-Aldrich Co. LLC

Safety & Documentation

Safety Information

Personal Protective Equipment 
NONH for all modes of transport
WGK Germany 
Flash Point(F) 
Not applicable
Flash Point(C) 
Not applicable
Protocols & Articles


MSMLS Online Plate Map

Metabolite descriptors included with the software download upon purchase of the product include: Name, Parent CID, molecular formula, molecular weight, CAS, ChEBI, HMDB ID, PubChem Compound and Subst...
Keywords: Mass spectrometry, Metabolites

Peer-Reviewed Papers


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