dc.contributor.advisor | Joksović, Ljubinka | |
dc.contributor.other | Ćirić, Andrija | |
dc.contributor.other | Šmit, Biljana | |
dc.contributor.other | Kreft, Samo | |
dc.creator | Mihailović, Nevena | |
dc.date.accessioned | 2020-10-24T12:31:00Z | |
dc.date.available | 2020-10-24T12:31:00Z | |
dc.date.issued | 2019-09-20 | |
dc.identifier.uri | http://eteze.kg.ac.rs/application/showtheses?thesesId=7531 | |
dc.identifier.uri | https://fedorakg.kg.ac.rs/fedora/get/o:1252/bdef:Content/download | |
dc.identifier.uri | https://nardus.mpn.gov.rs/handle/123456789/17536 | |
dc.description | U poslednjih nekoliko decenija, interes za izučavanjem poznatih i
pronalaženjem novih vrsta koje mogu imati značajan antioksidativni
potencijal sve više raste. Imajući u vidu da su fenolna jedinjenja
poznata kao jako dobri antioksidansi, a da su glavni izvori ovih
jedinjenja biljke, konstantno se izučavaju biljne vrste koje potencijalno poseduju
visok sadržaj prirodnih antioksidanasa.
Familija Rosaceae obuhvata veliki broj biljnih vrsta koje ljudi od
davnina koriste u svojoj ishrani, ali su mnoge divlje vrste nedovoljno
proučavane, pa je deo ove disertacije baziran na analizi fenolnih jedinjenja u
divljim plodovima jabuke, maline i trešnje. U cilju dobijanja maksimalnog
prinosa ovih jedinjenja iz biljnog materijala, izvršena je optimizacija metode
ekstrakcije fenolnih jedinjenja, i definisani su optimalni uslovi za
ekstrakciju, koji obuhvataju pravilan odabir rastvarača (i njegove koncentracije),
odnos mase uzorka i zapremine rastvarača, vreme i temperaturu ekstrakcije. U
ovako dobijenim ekstraktima, analiziran je ukupan sadržaj fenolnih jedinjenja
(ukupnih fenola, fenolnih kiselina, flavonoida i antocijanina), a rezultati su
omogućili određivanje optimalnih uslova ekstrakcije ovih jedinjenja u uzorcima
primenom softvera Design-Expert® i metodologije odziva površine (eng. Response
Surface Methodology).
Kvantifikacija pojedinačnih fenolnih jedinjenja u uzorcima dobijenim
ekstrakcijom pod optimalnim uslovima izvršena je HPLC metodom, pri čemu su
dobijeni rezultati potvrdili da su ovi plodovi bogati sadržajem biološki
važnih fenolnih jedinjenja. Dobijene vrednosti koncentracija pojedinačnih
fenolnih jedinjenja ukazale su da plodovi ispitivanih samoniklih vrsta
familije Rosaceae mogu biti značajan izvor ove grupe jedinjenja u ishrani ljudi.
Rezultati i metodologija analize fenolnog sastava ovih plodova, mogu biti od
značaja i za buduća ispitivanja i analizu sadržaja fenolnih jedinjenja u
plodovima biljaka sličnih karakteristika. Ispitana je i stabilnost i
biodostupnost ovih komponenti u organizmu, simulacijom uslova in vitro
Ugastrointestinalne digestije. Da bi se rasvetlio antioksidativni potencijal
testiranih uzoraka, primenjen je niz metoda koje ispituju njihovu sposobnost da
neutrališu štetne slobodno-radikalske vrste.
Iako postoji sve veća težnja za nalaženjem i upotrebom prirodnih
antioksidanasa, mogućnosti njihove univerzalne primene su često ograničene, pa
se pribegava dobijanju antioksidativnih jedinjenja sintetičkim putem. U tom
smislu, u ovom radu je izvršena sintetička modifikacija odabranih fenolnih
kiselina, sa ciljem nalaženja novih jedinjenja sa boljim biološkim aktivnostima,
pre svega antioksidativnom. Na ovaj način su dobijene dve serije jedinjenja, 1,2,4-
triazol-3-tioni i 1,3,4-oksadiazoli.
Dobijeni rezultati daju doprinos analizi fenolnih jedinjenja u prirodnim
proizvodima, njihovoj funkcionalizaciji i primeni | sr |
dc.description | In the past several decades, the interest in studying well-known and discovery of
new species that may have significant antioxidant potential is constantly growing.
Taking into account that phenolic compounds are known as good antioxidants,
and that the main sources of these compounds are plants, there is a constant pursuit for
plant species potentially possessing a high content of natural antioxidants.
The Rosaceae family includes a large number of plant species that humans have
used in their diet for a long time, but many wild species are insufficiently studied,
therefore part of this PhD thesis is based on the analysis of phenolic compounds in wild
apples, raspberries, and cherries (family Rosaceae). In order to obtain the maximum yield
of these compounds, optimization of the extraction method of phenolic compounds from
plant material was performed, and optimal conditions for extraction, including the
appropriate choice of the solvent (and its concentration), the solid to solvent ratio, the
time and temperature of the extraction, were defined. The total content of phenolic
compounds (total phenols, phenolic acids, flavonoids, and anthocyanins) was analyzed in
the obtained extracts, and the obtained results were used in determination of optimal
conditions for the extraction of these compounds in the samples using the DesignExpert® software and the response surface methodology.
The quantification of individual phenolic compounds in the samples obtained by
extraction under optimal conditions was performed by HPLC method and the results
confirmed that these fruits are rich in the biologically important phenolic compounds.
The obtained concentrations of individual phenolic compounds indicated that the studied
wild fruit species of the Rosaceae family could be a significant source of phenolic
compounds in human nutrition. The results and methodology of analyzing the phenolic
composition of these fruits can be of importance for future research and analysis of
phenolic compounds content in fruit or plants with similar characteristics. Furthermore,
the stability and bioaccessibility of these components in the organism were examined by
the simulation of the in vitro gastrointestinal digestion conditions. In order to clarify the
Iantioxidant potential of the tested samples, a number of methods for determination of the
ability of obtained extracts to neutralize harmful free-radical species have been applied.
Although there is a growing tendency to find and use natural antioxidants, the
possibilities of their universal application are often limited, therefore antioxidant
compounds are often synthetically obtained. The synthetic modification of selected
phenolic acids was carried out with the aim of finding a new series of compounds with
better biological activities, mainly antioxidant activity. Two series of novel compounds
were synthesized, 1,2,4-triazol-3-thiones and 1,3,4-oxadiazoles.
The obtained results in this PhD thesis contribute to the analysis of phenolic
compounds in natural products, their functionalization, and application. | en |
dc.format | application/pdf | |
dc.language | sr | |
dc.publisher | Универзитет у Крагујевцу, Природно-математички факултет | sr |
dc.relation | info:eu-repo/grantAgreement/MESTD/Basic Research (BR or ON)/172016/RS// | |
dc.rights | openAccess | en |
dc.rights.uri | https://creativecommons.org/licenses/by/4.0/ | |
dc.source | Универзитет у Крагујевцу | sr |
dc.title | Određivanje fenolnih jedinjenja u plodovima nekih biljaka iz familije Rosaceae i antioksidativne aktivnosti njihovih sintetičkih derivata | sr |
dc.type | doctoralThesis | en |
dc.rights.license | BY | |
dc.identifier.fulltext | https://nardus.mpn.gov.rs/bitstream/id/66147/Izvestaj_Nevena_Mihailovic_PMF.pdf | |
dc.identifier.fulltext | https://nardus.mpn.gov.rs/bitstream/id/66146/Disertacija.pdf | |
dc.identifier.rcub | https://hdl.handle.net/21.15107/rcub_nardus_17536 | |