Bromme 2000 J Pineal Res: Difference between revisions
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{{Publication | {{Publication | ||
|title=Brรถmme HJ, Mรถrke W, Peschke E, Ebelt H, Peschke D (2000) Scavenging effect of melatonin on hydroxyl radicals generated by alloxan. J | |title=Brรถmme HJ, Mรถrke W, Peschke E, Ebelt H, Peschke D (2000) Scavenging effect of melatonin on hydroxyl radicals generated by alloxan. J Pineal Res 44:366-72. | ||
|authors=Broemme HJ, | |info=[http://www.ncbi.nlm.nih.gov/pubmed/11068942 PMID: 11068942] | ||
|authors=Broemme HJ, Moerke W, Peschke E, Ebelt H, Peschke D | |||
|year=2000 | |year=2000 | ||
|journal=J. Pineal Res. | |journal=J. Pineal Res. | ||
|abstract=When organic compounds are irradiated with UV light at 254 nm, part of their covalent bonds can dissociate if the compound absorbs light at that wavelength. Therefore, photo-degradation depends strongly on the wavelength used. The energy of a light quanta at 254 nm amounts to approximately 110 kcal/mol quanta, which is in many cases higher than the binding energy of a variety of covalent bonds. As a consequence, the absorbing molecule is degraded. As melatonin absorbs light at 254 nm, this compound is vulnerable to UV light. In order to minimize undesired effects of other absorbing substances, we used as solvent mostly pure water and analyzed the influence of ฮปirr = 254 nm on the disappearance of the educt (melatonin) as well as on the appearance of products derived from melatonin in the presence of oxygen, argon, hydrogen peroxide, and ethanol by UVโVIS spectroscopy and high-performance liquid chromatography (HPLC) technique. N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK) appears to be the main, but obviously not the only product of photo-degradation of melatonin, independently of whether the system contains oxygen or not. If the system contains additionally hydrogen peroxide, a very strong oxidant, the hydroxyl radical (โขOH), is formed. Under such conditions, melatonin is not solely photo-degraded but also attacked by the formed โขOH which interact similarly with the formed main photo-product AFMK. Ethanol, as a potent scavenger of โขOH, efficiently blocks the effect of this aggressive radical even at low concentrations of that scavenger (0.1% v/v) but is less effective in preventing photo-degradation of melatonin. | |abstract=When organic compounds are irradiated with UV light at 254 nm, part of their covalent bonds can dissociate if the compound absorbs light at that wavelength. Therefore, photo-degradation depends strongly on the wavelength used. The energy of a light quanta at 254 nm amounts to approximately 110 kcal/mol quanta, which is in many cases higher than the binding energy of a variety of covalent bonds. As a consequence, the absorbing molecule is degraded. As melatonin absorbs light at 254 nm, this compound is vulnerable to UV light. In order to minimize undesired effects of other absorbing substances, we used as solvent mostly pure water and analyzed the influence of ฮปirr = 254 nm on the disappearance of the educt (melatonin) as well as on the appearance of products derived from melatonin in the presence of oxygen, argon, hydrogen peroxide, and ethanol by UVโVIS spectroscopy and high-performance liquid chromatography (HPLC) technique. N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK) appears to be the main, but obviously not the only product of photo-degradation of melatonin, independently of whether the system contains oxygen or not. If the system contains additionally hydrogen peroxide, a very strong oxidant, the hydroxyl radical (โขOH), is formed. Under such conditions, melatonin is not solely photo-degraded but also attacked by the formed โขOH which interact similarly with the formed main photo-product AFMK. Ethanol, as a potent scavenger of โขOH, efficiently blocks the effect of this aggressive radical even at low concentrations of that scavenger (0.1% v/v) but is less effective in preventing photo-degradation of melatonin. | ||
|keywords=Ethanol, High-performance liquid chromatography, Hydroxyl radical, Melatonin, N1-acetyl-N2-formyl-5-methoxykynuramine, Photo-degradation | |keywords=Ethanol, High-performance liquid chromatography, Hydroxyl radical, Melatonin, N1-acetyl-N2-formyl-5-methoxykynuramine, Photo-degradation | ||
}} | }} | ||
{{Labeling | {{Labeling | ||
|injuries=RONS | |area=Pharmacology;toxicology | ||
|preparations=Oxidase; | |injuries=Oxidative stress;RONS | ||
|preparations=Oxidase;biochemical oxidation | |||
|instruments=Oxygraph-2k | |instruments=Oxygraph-2k | ||
|additional=Melatonin, | |||
}} | }} |
Latest revision as of 08:07, 21 February 2020
Brรถmme HJ, Mรถrke W, Peschke E, Ebelt H, Peschke D (2000) Scavenging effect of melatonin on hydroxyl radicals generated by alloxan. J Pineal Res 44:366-72. |
Broemme HJ, Moerke W, Peschke E, Ebelt H, Peschke D (2000) J. Pineal Res.
Abstract: When organic compounds are irradiated with UV light at 254 nm, part of their covalent bonds can dissociate if the compound absorbs light at that wavelength. Therefore, photo-degradation depends strongly on the wavelength used. The energy of a light quanta at 254 nm amounts to approximately 110 kcal/mol quanta, which is in many cases higher than the binding energy of a variety of covalent bonds. As a consequence, the absorbing molecule is degraded. As melatonin absorbs light at 254 nm, this compound is vulnerable to UV light. In order to minimize undesired effects of other absorbing substances, we used as solvent mostly pure water and analyzed the influence of ฮปirr = 254 nm on the disappearance of the educt (melatonin) as well as on the appearance of products derived from melatonin in the presence of oxygen, argon, hydrogen peroxide, and ethanol by UVโVIS spectroscopy and high-performance liquid chromatography (HPLC) technique. N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK) appears to be the main, but obviously not the only product of photo-degradation of melatonin, independently of whether the system contains oxygen or not. If the system contains additionally hydrogen peroxide, a very strong oxidant, the hydroxyl radical (โขOH), is formed. Under such conditions, melatonin is not solely photo-degraded but also attacked by the formed โขOH which interact similarly with the formed main photo-product AFMK. Ethanol, as a potent scavenger of โขOH, efficiently blocks the effect of this aggressive radical even at low concentrations of that scavenger (0.1% v/v) but is less effective in preventing photo-degradation of melatonin. โข Keywords: Ethanol, High-performance liquid chromatography, Hydroxyl radical, Melatonin, N1-acetyl-N2-formyl-5-methoxykynuramine, Photo-degradation
Labels: MiParea: Pharmacology;toxicology
Stress:Oxidative stress;RONS
Preparation: Oxidase;biochemical oxidation
HRR: Oxygraph-2k
Melatonin