Related Experiment Video
Updated: Aug 20, 2026

Induction and Analysis of Oxidative Stress in Sleeping Beauty Transposon-Transfected Human Retinal Pigment Epithelial Cells
Published on: December 11, 2020
Melatonin does not react rapidly with hydrogen peroxide
Agnieszka Grzelak1, Ewa Macierzyńska, Grzegorz Bartosz
1Department of Molecular Biophysics, University of Łódź, Banacha 12/16, 90-237 Łódź, Poland. agrzelak@biol.uni.lodz.pl
Abstract:
It has been claimed that melatonin reacts directly with hydrogen peroxide with a very high rate constant (2.5 x 10(5)-2.3 x 10(6) M(-1) s(-1)) Both these values were derived from inhibition by melatonin of peroxidase-catalyzed oxidation of Phenol Red by hydrogen peroxide, assuming that this inhibition is due to direct scavenging of hydrogen peroxide by melatonin. In this study, we show that this reasoning is illegitimate and melatonin decreases the yield of oxidation of Phenol Red as a competitive substrate. Monitoring changes of concentration of hydrogen peroxide incubated with melatonin using Xylenol Orange points to poor reactivity of melatonin with H2O2.
More Related Videos
12:02Human Primary Trophoblast Cell Culture Model to Study the Protective Effects of Melatonin Against Hypoxia/reoxygenation-induced Disruption
Published on: July 30, 2016
05:16High Throughput Screening Assessment of Reactive Oxygen Species (ROS) Generation using Dihydroethidium (DHE) Fluorescence Dye
Published on: January 19, 2024
Related Concept Videos
Autoxidation of Ethers to Peroxides and Hydroperoxides
Regioselectivity of Electrophilic Additions-Peroxide Effect
Peroxisomes
Oxidation of Phenols to Quinones
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...
Catalysis
Phase I Reactions: Oxidation of Aliphatic and Aromatic Carbon-Containing Systems
Oxidation reactions are fundamental in aromatic carbon-containing systems. An example is the hydroxylation of phenobarbital, a process that transforms it into...