Fitokemijska i antioksidacijska svojstva polifenola u vrstama Juniperus oxycedrus L. i Juniperus phoenicea L.

master's thesis

• Title (english): Phytochemical and antioxidant properties of polyphenols of Juniperus oxycedrus L. and Juniperus phoenicea L.
• Author: Andrea Stanić
• Mentor: Maja Bival Štefan (mentor)
• Committee member: Marija Kindl (predsjednik povjerenstva)
• Committee member: Maja Bival Štefan (član povjerenstva)
• Committee member: Višnja Drinovac (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of pharmacognosy); Zagreb
• Defense date and country: 2018-07-09, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

U okviru ovog diplomskog rada po prvi put je istražen fitokemijski sastav smrekinja vrsta Juniperus oxycedrus L. i Juniperus phoenicea L. hrvatske flore te je ispitan antioksidacijski potencijal njihovih etanolnih ekstrakata. Istraživanja su provedena usporedno s farmakopejskom drogom Juniperi galbulus (smrekinje vrste Juniperus communis L.). Prisutnost flavonoidnih glikozida i aglikona dokazana je metodom tankoslojne kromatografije. Primjenom spektrofotometrijskih metoda određeno je da zrele smrekinje istraživanih Juniperus vrsta sadrže 0,3-1,1 % ukupnih polifenola među kojima 0,01-0,08 % flavonoida i 0,1-0,6 % trjeslovina. Antioksidacijski učinak etanolnih ekstrakata ispitan je različitim spektrofotometrijskim metodama u usporedbi s kvercetinom i troloksom. Među istraživanim vrstama utvrđeno je da ekstrakt vrste J. phoenicea posjeduje najbolju sposobnost hvatanja slobodnih DPPH radikala (IC50 = 17 μg/mL) i redukcije iona željeza(III) (IC50 = 65 μg/mL) dok su smrekinje vrste J. oxycedrus pokazale najbolju sposobnost keliranja iona željeza(II) (IC50 = 25 μg/mL). Dobiveni rezultati doprinose znanstvenim spoznajama o polifenolnim sastavnicama smrekinja istraživanih vrsta roda Juniperus te njihovoj antioksidacijskoj aktivnosti.

Abstract (english)

The phytochemical composition of the berries of Juniperus oxycedrus L. and Juniperus phoenicea L. from the Croatian flora and the antioxidant potential of their ethanolic extracts were studied in this thesis for the first time. The investigations were carried out in comparison with the pharmacopoeial drug Juniperi galbulus (the berries of Juniperus communis L.) Flavonoid glycosides and aglycones were detected with thin-layer chromatography. The content of 0.3-1.1 % of total polyphenols, out of which 0.01-0.08 % of flavonoids and 0.1-0.6 % of tannins, were determined spectrophotometrically in the ripe berries of selected Juniperus species. The antioxidant activity of the ethanolic extracts was tested by using various spectrophotometric methods in comparison with quercetin and trolox. Our study revealed that among investigated species the extract of J. phoenicea possessed the best DPPH free-radical scavenging activity (IC50 = 17 μg/mL) and ferric reducing ability (IC50 = 65 μg/mL) while the berries of J. oxycedrus showed the highest chelating activity (IC50 = 25 μg/mL). The obtained results contribute to the scientific knowledge of the polyphenolic compounds in the berries of selected Juniperus species as well as their antioxidant activity.

• Keywords: Juniperus communis; Juniperus oxycedrus; Juniperus phoenicea; smrekinje; flavonoidi; trjeslovine; antioksidacijsko djelovanje
• Keywords (english): Juniperus communis; Juniperus oxycedrus; Juniperus phoenicea; cone berries; flavonoids; tannins; antioxidant activity
• Language: croatian
• URN:NBN: urn:nbn:hr:163:187775
• 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: 2019-04-08 09:07:46