Antioksidacijsko djelovanje etanolnih ekstrakata odabranih vrsta roda Juniperus

master's thesis

• Title (english): Antioxidant activity of ethanolic extracts of selected Juniperus species
• Author: Ana-Marija Plećaš
• Mentor: Marija Kindl (mentor)
• Committee member: Marija Kindl (predsjednik povjerenstva)
• Committee member: Maja Bival Štefan (član povjerenstva)
• Committee member: Jasna Jablan (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of pharmacognosy); Zagreb
• Defense date and country: 2018-05-08, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

U okviru ovog diplomskog rada istražen je fitokemijski sastav i antioksidacijski učinak
polifenolnih sastavnica u etanolnim ekstraktima listova i grančica odabranih vrsta roda Juniperus
iz hrvatske flore (J. communis, J. oxycedrus i J. phoenicea). Metodom tankoslojne kromatografije
visoke djelotvornosti dokazana je prisutnost flavonoida i trjeslovina te su vrste J. communis i J.
oxycedrus istaknute kao bogat izvor rutina. Primjenom različitih spektrofotometrijskih metoda
određeno je da listovi i grančice istraživanih vrsta sadrže 3,0-3,9 % ukupnih polifenola među
kojima 0,4-0,5 % flavonoida i 1,2-1,8 % trjeslovina, od toga 0,2-0,4 % procijanidina.
Antioksidacijski učinak etanolnih ekstrakata ispitan je različitim spektrofotometrijskim metodama
u usporedbi s troloksom. Utvrđeno je da ekstrakti odabranih biljnih vrsta posjeduju sposobnost
hvatanja slobodnih DPPH radikala (IC50: 3,4-6,2 μg/mL) i redukcije iona željeza(III) (IC50: 13,7-
21,5 μg/mL). Dobiveni rezultati pokazuju da su istraživane vrste roda Juniperus bogat izvor
polifenolnih spojeva koji vrlo vjerojatno doprinose utvrđenoj antioksidacijskoj aktivnosti njihovih
etanolnih ekstrakata.

Abstract (english)

The phytochemical composition and the antioxidant activity of polyphenols in the ethanolic
extracts of leaves and branches of selected Juniperus species from the Croatian flora (J. communis,
J. oxycedrus and J. phoenicea) were studied in this thesis. Flavonoids and tannins were detected
with high-performance thin-layer chromatography. Moreover, J. communis and J. oxycedrus were
found to be a rich source or rutin. The content of 3.0-3.9 % of total polyphenols in the leaves and
branches, as well as 0.4-0.5 % of flavonoids and 1.2-1.8 % of tannins (out of which 0.2-0.4 % of
procyanidins) among them was determined spectrophotometrically. The antioxidant activity of the
ethanolic extracts was tested by using various spectrophotometric methods in comparison with
trolox. Our study revealed that tested extracts possessed DPPH free-radical scavenging activity
(IC50: 3.4-6.2 μg/mL), as well as ferric reducing ability (IC50: 13.7-21.5 μg/mL). According to the
results, the investigated species of the Juniperus genus are a rich source of polyphenolic
compounds which most likely contribute to the confirmed antioxidant activity of their ethanolic
extracts.

• Keywords: Juniperus communis; Juniperus oxycedrus; Juniperus phoenicea; flavonoidi; trjeslovine; antioksidacijsko djelovanje
• Keywords (english): Juniperus communis; Juniperus oxycedrus; Juniperus phoenicea; flavonoids; tannins; antioxidant activity
• Language: croatian
• URN:NBN: urn:nbn:hr:163:671240
• 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
• Created on: 2018-12-12 12:35:44