Phytochemical content and antioxidant potential of petals and tepals of selected flowering plants

Biljke su zauzele različite aspekte našega života, koristimo ih u kozmetici, medicini, kao začine i hranu, kao bojila te u industriji ulja. Industrijska je praksa upotrebljavati određeni dio biljke, dok se ostali dijelovi uglavnom zanemare i ne iskorištavaju. S ekološkog i ekonomskog aspekta, takav način „djelomičnog“ iskorištavanja biljaka nije održiv. Cilj ovog diplomskog rada bio je usporediti kvalitativni i kvantitativni sastav bioaktivnih spojeva, te antioksidacijski potencijal etanolnih ekstrakata tepala/latica šafrana, šumskog sljeza, pravog duhana, suncokreta i ljekovitog nevena kako bi se doprinijelo boljem razumijevanju biopotencijala ovog biljnog materijala. Spektrofotometrijski je određen udio različitih skupina bioaktivnih spojeva, te antioksidacijski kapacitet ekstrakata. Ekstrakti tepala šafrana sadrže značajno veći udio ukupnih fenolnih spojeva, hidroksicimetnih kiselina, flavonola i proantocijanidina u odnosu na ostale analizirane uzorke. 70%-tni etanolni ekstrakt duhana sadrži više ukupnih flavonoida u odnosu na ostale istraživane cvjetnice. Najveći udio ukupnih flavonoida u 40%-tnom etanolu imali su ekstrakti latica suncokreta. Značajno veći udio karotenoida zabilježila sam kod ekstrakata latica nevena i suncokreta. U sve tri korištene metode mjerenja antioksidacijskog kapaciteta u ekstraktima s 40%-tnim etanolom latice suncokreta i sljeza imale su najviše vrijednosti, dok su u ekstraktima sa 70%-tnim etanolom latice suncokreta bile najučinkovitije. Na temelju ovoga zaključujem da su latice suncokreta i sljeza bogatije antioksidansima od ostalih uzoraka.Plants have occupied different aspects of our life, we use them in cosmetics, medicine, as spices and food, as dyes and in oil the industry. Most of these plants are known for one of their plant organs, and these are generally not flowers, petals and tepals. It is industrial practice to use a certain part of the plant while the other parts are mostly ignored and not used. From an ecological and economic point of view, „partial“ exploitation of plants is not sustainable. The aim of this thesis was to compare the qualitative and quantitative composition of bioactive compounds, and the antioxidant potential of ethanolic extracts of tepals/petals of saffron, common mallow, real tobacco, sunflower and medicinal calendula in order to contribute to a better understanding of the biopotential of this plant material. The proportion of different groups of bioactive compounds and the antioxidant capacity of the extracts were determined spectrophotometrically. Saffron tepal extracts contained a significantly higher proportion of total phenolic compounds, hydroxycinnamic acids, flavonols and proanthocyanidins compared to other analyzed samples. The 70% ethanol extract of tobacco contained more total flavonoids compared to other investigated flowering plants. Sunflower petal extracts had the highest proportion of total flavonoids in 40% ethanol. I noted a significantly higher proportion of carotenoids in the extracts of marigold and sunflower petals. In all three used methods of measuring antioxidant capacity, sunflower and common mallow petals had the highest values in extracts with 40% ethanol, while sunflower petals were the most effective in extracts with 70% ethanol. Based on this, I conclude that sunflower and common mallow petals are richer in antioxidants than other samples