Fitokemijski sastav i antioksidacijsko djelovanje komercijalno dostupnih ekstrakata acerole

master's thesis

• Title (english): Phytochemical composition and antioxidant activity of the commercially available acerola extracts
• Author: Sara Pranjić
• Mentor: Maja Bival Štefan (mentor)
• Committee member: Maja Bival Štefan (predsjednik povjerenstva)
• Committee member: Marijana Zovko Končić (član povjerenstva)
• Committee member: Lidija Bach-Rojecky (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of pharmacognosy); Zagreb
• Defense date and country: 2023-09-08, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

U ovom diplomskom radu ispitan je fitokemijski sastav i antioksidacijsko djelovanje različitih komercijalno
dostupnih ekstrakata acerole. Kvalitativna analiza flavonoida, fenolnih kiselina i trjeslovina provedena je
tankoslojnom kromatografijom (TLC) na tankom sloju silikagela koji je činio nepokretnu fazu uz smjesu
prikladnih otapala kao pokretne faze. U plodovima su, računajući Rf-vrijednosti (faktor zaostajanja) i
usporedbom boje i intenziteta zone fluorescencije ispitivanih i poredbenih otopina otkriveni rutin
(flavonoidi), kavena i klorogenska kiselina (fenolne kiseline) te galna kiselina (trjeslovine) u tragovima.
Spektrofotometrijsko određivanje sadržaja flavonoida i fenolnih kiselina izvršeno je pomoću UV-Vis
spektrofotometra mjerenjem maksimuma apsorbancije na prikladnim valnim duljinama. U ekstraktima ploda
određene su nešto niže vrijednosti navedenih bioaktivnih sastavnica nego što je bilo za očekivati prije
provođenja analize. Udio flavonoida u plodovima, izražen kao izokvercitrozid, kretao se od 0,003% do
0,046%, dok je sadržaj fenolnih kiselina bio u rasponu od 0,053% do 0,806% za ružmarinsku kiselinu,
odnosno od 0,048% do 0,995% za klorogensku kiselinu. Određivanje sadržaja trjeslovina
spektrofotometrijskim metodama nije provedeno budući da je TLC analiza pokazala jedva primjetne količine
istih u samo trima uzorcima, dok u ostalima nisu pronađeni. Sadržaj vitamina C analiziran je tekućinskom
kromatografijom visoke djelotvornosti. Antioksidacijska sposobnost ispitana je spektrofotometrijskim
metodama određivanja sposobnosti hvatanja DPPH slobodnog radikala te određivanja sposobnosti hvatanja
radikala dušikovog (II) oksida.

Abstract (english)

In this diploma thesis, the phytochemical composition and antioxidant activity of various commercially
available acerola extracts were examined. Qualitative analysis of flavonoids, phenolic acids and tannins was
performed by thin layer chromatography (TLC) on a thin layer of silica gel, which formed the stationary
phase with a mixture of suitable solvents as the mobile phase. Rutin (flavonoids), caffeic and chlorogenic
acid (phenolic acids) and gallic acid (tannins) were detected in the fruits by calculating the Rf-values and
comparing the color and intensity of the fluorescence zone of the tested and standard solutions.
Spectrophotometric determination of the content of flavonoids and phenolic acids was performed using a UVVis spectrophotometer by measuring the absorbance maximum at appropriate wavelengths. In the fruit
extracts, slightly lower values of the mentioned bioactive components were determined than was to be
expected before conducting the analysis. The amount of flavonoids in the fruits, expressed as isoquercitroside,
varies from 0.003% to 0.046%, while the content of phenolic acids was ranged from 0.053% to 0.806% for
rosmarinic acid and 0.048% up to 0.995% for chlorogenic acid. Determination of the content of tannins by
spectrophotometric methods was not carried out, since the TLC analysis showed barely noticeable amounts
in only three samples, while none were found in the rest. Vitamin C content was analyzed by highperformance liquid chromatography. The antioxidant capacity was tested by spectrophotometric methods of
determining the ability to capture the DPPH free radical and determining the ability to capture the nitrogen
(II) oxide radical.

• Keywords: acerola; plod; ekstrakti; flavonoidi; fenolne kiseline; trjeslovine; vitamin C; tankoslojna kromatografija; spektrofotometrija; antioksidacijski potencijal
• Keywords (english): acerola; fruit; extracts; flavonoids; phenolic acids; tannins; vitamin C; thin-layer chromatography; spectrophotometry; antioxidant potential
• Language: croatian
• URN:NBN: urn:nbn:hr:163:452320
• 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: Embargoed access; Embargo expiration date: 2025-09-08
• Created on: 2024-01-18 14:05:47