Kinetički izotopni efekti u reakcijama fenolnih kiselina i DPPH• radikala

Lalić, Josipa

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master's thesis

Kinetički izotopni efekti u reakcijama fenolnih kiselina i DPPH• radikala

Zagreb: University of Zagreb, Faculty of Pharmacy and Biochemistry, 2022. urn:nbn:hr:163:541408

Lalić, Josipa

University of Zagreb
Faculty of Pharmacy and Biochemistry
Department of physical chemistry

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APA 6th Edition

Lalić, J. (2022). Kinetički izotopni efekti u reakcijama fenolnih kiselina i DPPH• radikala (Master's thesis). Zagreb: University of Zagreb, Faculty of Pharmacy and Biochemistry. Retrieved from https://urn.nsk.hr/urn:nbn:hr:163:541408

MLA 8th Edition

Lalić, Josipa. "Kinetički izotopni efekti u reakcijama fenolnih kiselina i DPPH• radikala." Master's thesis, University of Zagreb, Faculty of Pharmacy and Biochemistry, 2022. https://urn.nsk.hr/urn:nbn:hr:163:541408

Chicago 17th Edition

Harvard

Lalić, J. (2022). 'Kinetički izotopni efekti u reakcijama fenolnih kiselina i DPPH• radikala', Master's thesis, University of Zagreb, Faculty of Pharmacy and Biochemistry, accessed 23 January 2025, https://urn.nsk.hr/urn:nbn:hr:163:541408

Vancouver

Lalić J. Kinetički izotopni efekti u reakcijama fenolnih kiselina i DPPH• radikala [Master's thesis]. Zagreb: University of Zagreb, Faculty of Pharmacy and Biochemistry; 2022 [cited 2025 January 23] Available at: https://urn.nsk.hr/urn:nbn:hr:163:541408

IEEE

J. Lalić, "Kinetički izotopni efekti u reakcijama fenolnih kiselina i DPPH• radikala", Master's thesis, University of Zagreb, Faculty of Pharmacy and Biochemistry, Zagreb, 2022. Available at: https://urn.nsk.hr/urn:nbn:hr:163:541408

Cite this item: https://urn.nsk.hr/urn:nbn:hr:163:541408

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Metadata

Title	Kinetički izotopni efekti u reakcijama fenolnih kiselina i DPPH• radikala
Title (english)	Kinetic isotope effects in reactions of phenolic acids and DPPH• radicals
Author	Josipa Lalić
Mentor	Cvijeta Jakobušić Brala (mentor)
Committee member	Cvijeta Jakobušić Brala (predsjednik povjerenstva)
Committee member	Mirela Matić (član povjerenstva)
Committee member	Viktor Pilepić (član povjerenstva)
Granter	University of Zagreb Faculty of Pharmacy and Biochemistry (Department of physical chemistry) Zagreb
Defense date and country	2022-07-19, Croatia
Scientific / art field, discipline and subdiscipline	NATURAL SCIENCES Chemistry Physical Chemistry
Abstract	Fenolni spojevi se sve više istražuju radi mnogobrojnih bioloških učinaka među kojima se ističe antioksidativni učinak. Za praćenje antioksidativnog učinka često se koristi metoda s DPPH• radikalom. U ovom diplomskom radu određene su konstante brzine reakcija fenolnih kiselina: p-kumarinske kiseline, ferulične kiseline, vanilinske kiseline, vanilina i flavonoida kvercetina s DPPH• u dioksanu te smjesi otapala dioksan-voda (0,99:0,01 v/v i 0,95:0,05 v/v). Određeni su kinetički izotopni efekti reakcija navedenih fenolnih spojeva i DPPH• u smjesi otapala dioksan-voda (0,99:0,01 v/v i 0,95:0,05 v/v). Dobiveni kinetički izotopni efekti, za sve spojeve osim vanilina, upućuje na reakcijski mehanizam HAT (hydrogen atom transfer) ili PCET (proton-coupled electron transfer), što podrazumijeva da u stupnju koji određuje brzinu reakcije dolazi i do prijelaza protona i do prijelaza elektrona. U slučaju vanilina dobiven je inverzni KIE koji upućuje na drugačiji i složeniji mehanizam reakcije. U literaturi nisu pronađeni podatci o kinetičkim izotopnim efektima navedenih reakcija. Dobiveni rezultati doprinose razumijevanju kinetike i mehanizma reakcija fenolnih spojeva i radikala, s čime je povezan jedan dio antioksidativne aktivnosti ovih spojeva.
Abstract (english)	Phenolic compounds are increasingly being researched for their numerous biological effects, among which the antioxidant effect stands out. To monitor the antioxidant potential, the DPPH• free radical scavenging method is often used. In this thesis, the reaction rate constants of phenolic acids: p-coumaric acid, ferulic acid, vanillic acid, vanillin and the flavonoid quercetin with DPPH• in dioxane and solvent mixture dioxane-water (0,99:0,01 v/v and 0,95:0,05 v/v) were examined. The kinetic isotopic effects for the mentioned phenolic compounds and DPPH• reaction in the solvent mixture dioxane-water (0,99:0,01 v/v and 0,95:0,05 v/v) were determined. The obtained kinetic isotope effects, for all compounds except vanillin, refer to the reaction mechanism HAT (hydrogen atom transfer) or PCET (proton-coupled electron transfer), which implies that in the rate-determining step of the reaction, both proton and electron transitions occur. In the case of vanillin, an inverse KIE was obtained, which points to a different and more complex reaction mechanism. No data on the kinetic isotope effects for the mentioned reactions were found in the literature. The obtained results contribute to the understanding of the kinetics and mechanism of reactions of phenolic compounds with radicals, with which a part of the antioxidant activity of these compounds is associated.
Keywords
Keywords (english)
Language	croatian
URN:NBN	urn:nbn:hr:163:541408
Study programme	Title: Pharmacy Study programme type: university Study level: integrated undergraduate and graduate Academic / professional title: magistar/magistra farmacije (magistar/magistra farmacije)
Type of resource	Text
File origin	Born digital
Access conditions	Open access
Terms of use
Repository	Repository of Faculty of Pharmacy and Biochemistry University of Zagreb
Created on	2022-07-22 12:49:18