Učinak saharoze na sadržaj fenolnih spojeva i antioksidacijski kapacitet smilja (Helichrysum italicum (Roth) G. Don)

master's thesis

• Title (english): Effects of saccharose on flavonoid content an antioxidant capacity of immortelle Helichrysum italicum (Roth) G. Don)
• Author: Dino Horvat
• Mentor: Branka Pevalek-Kozlina (mentor)
• Committee member: Branka Pevalek-Kozlina (predsjednik povjerenstva)
• Committee member: Ines Radanović (član povjerenstva)
• Committee member: Draginja Mrvoš-Sermek (član povjerenstva)
• Committee member: Vesna Petrović Peroković (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2015-07-10, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Smilje (Helichrysum italicum (Roth) G. Don) je aromatični polugrm mediteranskog područja poznato po zlatno-žutim cvjetovima i lako prepoznatljivom mirisu. Ime roda Helichrysum, koje potječe od grčkih riječi helios, što znači sunce, i chryos, što znači zlato, daje do znanja kako vrste ovog roda imaju karakteristične cvatove svijetložute boje. U Hrvatskoj raste po kamenjarima, bušicima, na stjenovotom travnjacima, od obalnog do brdskog pojasa u području mediteranske i submediteranske klime. Cilj ovog istraživanja bio je utvrditi utječe li povećanje koncentracije saharoze u hranjivoj podlozi na količinu fenolnih spojeva (ukupnih fenola, tanina, flavonoida i antocijana) i antioksidacijski kapacitet smilja. U istraživanju su korišteni samo listovi smilja koji su ekstrahirani pomoću 50 %-tnog etanola. Rezultati istraživanja pokazali su kako povećanje koncentracije saharoze u hranjivoj podlozi značajno povećava količinu svih fenolnih spojeva u listovima smilja što se može pripisati stimulirajućem učinku saharoze na enzim fenilalanin-amonij-lijazu (PAL) koji je glavni enzim u sintezi sekundarnih fenolnih metabolita u biljaka. Za određivanje antioksidacijskog kapaciteta ekstrakata smilja korištene su metode ABTS, DPPH i FRAP. Porastom koncentracije saharoze, a time i povećanjem količine fenolnih spojeva u listovima smilja, povećavao se i antioksidacijski kapacitet smilja prema metodama ABTS i FRAP dok je metoda DPPH pokazala smanjenje antioksidacijske aktivnosti što se može objasniti stvaranjem vodikovih veza između otapala (etanol, voda) i povišene količine fenolnih spojeva koje su utjecale na smanjenu stopu reakcije između radikala i antioksidanasa (fenolnih spojeva) iz listova smilja.

Abstract (english)

Immortelle (Helichrysum italicum (Roth) G. Don) is an aromatic semi-shrub of Mediterranean region known for its golden-yellow flowers and easily recognizable smell. Helichrysum genus name, which comes from the Greek words helios, meaning sun, and chryos, which means gold, makes it clear how the species of this genus have a distinctive blossoms light-yellow color. In Croatia immortelle grows at a rocky, busic, cliffy lawns, from coastal to mountainous zone in the mediterranean and sub-mediterranean climate. The aim of this study was to determine the influence of the increasing concentration of saccharose in the nutrient medium on the amount of phenolic compounds (total phenols, tannins, flavonoids and anthocyanins) and antioxidant capacity of immortelle. In this study only leaves of Immortelle were used. They were extracted using 50 % ethanol. The results showed that conclusive increase of saccharose concentration in the nutrient medium, significantly increased the amount of phenolic compounds in the immortelle leaves. That could be attributed to the stimulating effect of saccharose on enzyme phenylalanine-ammonia-lyase (PAL ), a major enzyme in the synthesis of secondary phenolic metabolites in plants. ABTS, DPPH and FRAP assays were used to determine the antioxidant capacity of immortelle extracts. With increasing concentration of saccharose, and thus increasing amount of phenolic compounds in the immortelle leaves the antioxidant capacity was higher according to ABTS and FRAP assays. DPPH assay showed a decline in antioxidant activity which could be explained by the formation of hydrogen bonds between the solvent (ethanol and water) and elevated levels of phenolic compounds that have influenced on reduced rate of reaction between radicals and antioxidants (phenolic compounds) from the immortelle leaves.

• Keywords: smilje; Helichrysum italicum (Roth) G. Don; fenoli; tanini; flavonoidi; antocijani; antioksidacijski kapacitet; antioksidansi
• Keywords (english): Immortelle; Helichrysum italicum (Roth) g. Don; phenols; tannins; falvonoids; antocyanins; antioxidant capacity; antioxidants
• Language: croatian
• URN:NBN: urn:nbn:hr:217:547811
• Study programme: Title: Integrated undergraduate and graduate university study of Biology and Chemistry Education; specializations in: Integrated undergraduate and graduate university study of Biology and Chemistry Education; Course: Integrated undergraduate and graduate university study of Biology and Chemistry Education; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra edukacije biologije i kemije (magistar/magistra edukacije biologije i kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-04-21 10:26:16