Measurement of antioxidant ability of melatonin and serotonin by the DMPD and CUPRAC methods as trolox equivalent

J Enzyme Inhib Med Chem. 2008 Dec;23(6):871-6. doi: 10.1080/14756360701626223.


Melatonin (N-acetyl-5-methoxytryptamine) is the chief secretory product of the pineal gland and synthesized enzymatically from serotonin (5-hydroxytryptamine). These indoleamine derivatives play an important role in the prevention of oxidative damage. In the present study, DMPD radical scavenging and cupric ion (Cu(2+)) reducing ability of melatonin and serotonin as trolox equivalent antioxidant activity (TEAC) was investigated. Melatonin and serotonin demonstrated 73.5 and 127.4 microg/mL trolox equivalent DMPD( radical+) scavenging activity at the concentration of 100 microg/mL. Also, at the same concentration, melatonin and serotonin showed 14.41 and 116.09 microg/mL trolox equivalent cupric ion (Cu(2+)) reducing ability. These results showed that melatonin and serotonin had marked DMPD(radical+) radical scavenging and cupric ions (Cu(2+)) reducing ability. Especially, serotonin had higher DMPD radical scavenging and cupric ions (Cu(2+)) reducing activity than melatonin because of its phenolic group.

MeSH terms

  • Antioxidants / analysis*
  • Antioxidants / chemistry
  • Chromans / chemistry*
  • Decanoic Acids / analysis*
  • Decanoic Acids / chemistry*
  • Free Radicals / chemistry
  • Melatonin / analysis*
  • Melatonin / chemistry
  • Molecular Structure
  • Piperidones / analysis*
  • Piperidones / chemistry
  • Serotonin / analysis*
  • Serotonin / chemistry


  • Antioxidants
  • Chromans
  • Decanoic Acids
  • Free Radicals
  • Piperidones
  • dimethylpiperidone
  • Serotonin
  • decanoic acid
  • Melatonin
  • 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid