Title
Fotosenzibilizovana oksidacija lipida u rastvoru indukovana kontinualnim UV-stresom u prisustvu kvercetina
Creator
Stanojević, Jelena S. 1987-
Copyright date
2017
Object Links
Select license
Autorstvo-Nekomercijalno-Bez prerade 3.0 Srbija (CC BY-NC-ND 3.0)
License description
Dozvoljavate samo preuzimanje i distribuciju dela, ako/dok se pravilno naznačava ime autora, bez ikakvih promena dela i bez prava komercijalnog korišćenja dela. Ova licenca je najstroža CC licenca. Osnovni opis Licence: http://creativecommons.org/licenses/by-nc-nd/3.0/rs/deed.sr_LATN. Sadržaj ugovora u celini: http://creativecommons.org/licenses/by-nc-nd/3.0/rs/legalcode.sr-Latn
Language
Serbian
Cobiss-ID
Theses Type
Doktorska disertacija
description
Datum odbrane: 28.8.2017.
Other responsibilities
mentor
Cvetković, Dragan 1977-
član komisije
Cakić, Milorad
član komisije
Šmelcerović, Andrija
član komisije
Zvezdanović, Jelena
član komisije
Stanojević, Ljiljana
Academic Expertise
Tehničko-tehnološke nauke
University
Univerzitet u Nišu
Faculty
Tehnološki fakultet
Group
Katedra za hemijske nauke
Alternative title
Photosensitized lipid oxidation in solution induced by continuous UV-stress in the presence of quercetin
Publisher
[Ј. Stanojević]
Format
281 str.
description
Biografija: str. 276
description
Technological engineering,Chemistry and chemical technology
Abstract (en)
The aim of the present PhD thesis was to study UV(-A and -B)
induced lipid peroxidation sensitized by synthetic (benzophenone)
and endogenous photosensitizers (bilirubin, riboflavin) in the
presence of quercetin as antioxidant. Phospholipid mixure was used
as a ”protective target” and the whole process was followed in the
simplest possible system – methanolic solution.
Photodegradation of sensitizers and quercetin with the consequent
occurrence of their degradation products both individually and in the
mutual mixture, as well as in the mixture with phospholipids (where
beside the mentioned processes peroxides production occurs), was
followed by RP-HPLC chromatography. Unambiguous identification
of degradation products was enabled by UHPLC-ESI-MS technique
while free radical species were identified by EPR spectroscopy.
Benzophenone was photostabile, photodegradation of bilirubin gave
biliverdin and dipiroles while main degradation products of riboflavin
were lumichrome and lumiflavin. Insight into the mechanism and
control of lipid peroxidation provided ”conjugated diene” assay, by
following the signal at 234 nm (the absorption maximum of
conjugated diene structures). As typical Type I sensitizer,
benzophenone generated superoxide radical anion, while riboflavin
generated both superoxide and singlet oxygen by mixed Type I and II
mechanisms. Irradiation of bilirubin-riboflavin mixture showed, in the
indirect way, that bilirubin is typical Type II sensitizer.
Photosensitizing capability of the studied sensitizers decreases in the
order: riboflavin > benzophenone > bilirubin. Quercetin exhibited
efficient antioxidant activity, mediated by its own degradation, in
terms of its preventive (absorbing UV radition), chain-breaking
activities (scavenging of generated superoxide radical anion, singlet
oxygen and lipid peroxides) and besides all this effectively quenched
triplet exited states of sensitizers (first of all benzophenone and
riboflavin).
Authors Key words
Fotohemija, Benzofenon, Riboflavin, Bilirubin, Kvercetin,
UV ozračivanje, Lipidna peroksidacija
Authors Key words
Photochemistry, Benzophenone, Riboflavin, Bilirubin, Quercetin, UV irradiation, Lipid peroxidation
Classification
544.52:547.915(043.3)
Subject
577.125:577.34
Subject
P 402
Type
Elektronska teza
Abstract (en)
The aim of the present PhD thesis was to study UV(-A and -B)
induced lipid peroxidation sensitized by synthetic (benzophenone)
and endogenous photosensitizers (bilirubin, riboflavin) in the
presence of quercetin as antioxidant. Phospholipid mixure was used
as a ”protective target” and the whole process was followed in the
simplest possible system – methanolic solution.
Photodegradation of sensitizers and quercetin with the consequent
occurrence of their degradation products both individually and in the
mutual mixture, as well as in the mixture with phospholipids (where
beside the mentioned processes peroxides production occurs), was
followed by RP-HPLC chromatography. Unambiguous identification
of degradation products was enabled by UHPLC-ESI-MS technique
while free radical species were identified by EPR spectroscopy.
Benzophenone was photostabile, photodegradation of bilirubin gave
biliverdin and dipiroles while main degradation products of riboflavin
were lumichrome and lumiflavin. Insight into the mechanism and
control of lipid peroxidation provided ”conjugated diene” assay, by
following the signal at 234 nm (the absorption maximum of
conjugated diene structures). As typical Type I sensitizer,
benzophenone generated superoxide radical anion, while riboflavin
generated both superoxide and singlet oxygen by mixed Type I and II
mechanisms. Irradiation of bilirubin-riboflavin mixture showed, in the
indirect way, that bilirubin is typical Type II sensitizer.
Photosensitizing capability of the studied sensitizers decreases in the
order: riboflavin > benzophenone > bilirubin. Quercetin exhibited
efficient antioxidant activity, mediated by its own degradation, in
terms of its preventive (absorbing UV radition), chain-breaking
activities (scavenging of generated superoxide radical anion, singlet
oxygen and lipid peroxides) and besides all this effectively quenched
triplet exited states of sensitizers (first of all benzophenone and
riboflavin).
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