Identification of free radicals induced by UV irradiation in collagen water solutions
| Autor: | Nunu Metreveli, K Jariashvili, Marine Dgebuadze, E Chikvaidze, Louisa Namicheishvili, Alina Sionkowska |
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| Rok vydání: | 2008 |
| Předmět: |
Free Radicals
Hydrogen Ultraviolet Rays Radical Biophysics chemistry.chemical_element In Vitro Techniques Photochemistry medicine.disease_cause Adduct law.invention Cyclic N-Oxides chemistry.chemical_compound law medicine Animals Radiology Nuclear Medicine and imaging Irradiation Hydrogen peroxide Electron paramagnetic resonance Acetic Acid Radiation Radiological and Ultrasound Technology Hydroxyl Radical Photodissociation Electron Spin Resonance Spectroscopy Water Photochemical Processes Rats Solutions chemistry Spin Labels Collagen Ultraviolet |
| Zdroj: | Journal of Photochemistry and Photobiology B: Biology. 93:61-65 |
| ISSN: | 1011-1344 |
| DOI: | 10.1016/j.jphotobiol.2008.06.003 |
| Popis: | Electron paramagnetic resonance (EPR) method has shown that hydrogen atoms and acetic acid free radicals appear in surrounding acetic acid–water solution of collagen under ultraviolet (UV) irradiation. These free radicals interact with the collagen molecule; consequently, seven superfine components of EPR spectrum with the split of aH = 11.3 G and g-factor 2.001 appear. It is assumed that this spectrum is related to the free radical occurred on the proline residue in collagen molecule. In order to discover OH hydroxyl radicals even in minor concentration, spin trap 5.5-dimethyl-1-pyrroline N-oxide (DMPO) has been applied. During the irradiation of collagen water solution in the presence of spin trap, EPR spectrum of the DMPO/ OH adduct has not been identified, while the above mentioned spectrum has been observed once the hydrogen peroxide H2O2 and FeSO4 were added to the sample. That means that water photolysis does not take place in collagen water-solution due to UV irradiation. It was suggested that occurrence of hydrogen radical is connected with the electron transmission to the hydrogen ion. The possible source of free electrons can be aromatic residues, photo ionization of which takes place in collagen molecule due to UV irradiation. |
| Databáze: | OpenAIRE |
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