Ispitivanje antioksidativne i antitumorske aktivnosti ekstrakata tri odabrane vrste lišajeva Cladonia subulata, Pleurosticta acetabulum i Physcia semipinnata Tomivić, Jovica, 1987- Cilj ove doktorske disertacije je ispitivanje hemijskog sastava, antioksidativne i antitumorske aktivnosti ekstrakata tri vrste lišajeva: Cladonia subulata, Pleurosticta acetabulum i Physcia semipinnata. Ispitivanje hemijskog sastava acetonskih i metanolskih ekstrakata obuhvatao je HPLC-UV analizu ekstrakata kao i određivanje ukupnog sadržaja fenola i flavonoida u ekstraktima. Ispitivani esktrakti su pokazali visok sadržaj ukupnih fenola (21,31±1,19 do 73,45±0,82 mg GA/g) i flavonoida (8,48±0,57 do 19,27±0,37 mg RU/g). Ispitivanje ekstrakata lišajeva HPLC-UV analizom potvrđeno je prisustvo dve grupe sekundarnih metabolita depsidona i depsida: hipoprotocetrarinska kiselina, fumaroprotocetrarinska kiselina, salazinska kiselina, norstihninska kiselina, protocetrarinska kiselina, evernijska kiselina, atranorin, lekanorna kiselina i obtusinska kiselina. Ispitivanje biološke aktivnosti ekstrakata obuhvatalo je evaluaciju antioksidativne i antitumorske aktivnosti. Antioksidativna aktivnost je utvrđena praćenjem ukupnog antioksidativnog kapaciteta, sposobnosti neutralizacije DPPH radikala, sposobnosti neutralisanja hidroksil radikala, redukcinog potencijala i inhibicije lipidne peroksidacije. Rezultati ispitivanja in vitro antioksidativne aktivnosti pokazuju da ekstrakti ispitivanih vrsta lišajeva poseduju značajan antioksidativni potencijal. Antitumorska aktivnost ekstrakata lišajeva procenjena je korišćenjem MTT testa ispitivanjem vijabilnosti i proliferacije na ćelijama Hela S3 (adenokarcinom cerviksa) i LS174 (ćelije karcinoma debelog creva). Ispitivani ekstrakti pokazali su antitumorsku aktivnost u različitim koncetracijama (IC50=13,55 do >200 μg/ml), u zavisnosti od ekstrakta i ispitivane ćelijske linije. Na osnovu dobijenih rezultata, može se prepostaviti da vrste lišajeva Cladonia subulata, Pleurosticta acetabulum i Physcia semipinnata u budućnosti mogu naći svoju potencijalnu primenu u medicini, farmaceutskoj, prehrambenoj i kozmetičkoj industriji, kao i u razvoju novih fitopreparata. The aim of this doctoral thesis is to investigate the chemical composition, antioxidant and antitumor activity of the extracts of three lichen species: Cladonia subulata, Pleurosticta acetabulum and Physcia semipinnata. Examination of the chemical composition of acetone and methanol extracts included the HPLC-UV analysis of the extracts as well as the determination of the total content of phenol and flavonoids in the extracts. The examined extracts showed a high content of total phenols (21.31 ± 1.19 to 73.45 ± 0.82 mg GA/g) and flavonoids (8.48 ± 0.57 to 19.27 ± 0.37 mg RU/g). Examination of extracts of lichens by HPLC-UV analysis confirmed the presence of two groups of secondary metabolites of depsidone and depside: hypoprotocetraric acid, fumaroprotocetraric acid, salazinic acid, norstictic acid, protocetraric acid, evernic acid, atranorine, lecanoric acid and obtusic acid. The study of the biological activity of extracts involved the evaluation of antioxidant and antitumor activity. The antioxidant activity was determined by monitoring the total antioxidant capacity, the ability to neutralize DPPH radicals, the ability to neutralize hydroxyl radicals, reducing potential, and inhibiting lipid peroxidation. The results of an in vitro antioxidative activity test show that the extracts of the tested lichen species have a significant antioxidant potential. Antitumor activity of lichen extracts was assessed using the MTT test by testing viability and proliferation of Hela S3 cells (cervix adenocarcinoma) and LS174 (colon cancer cells). The investigated extracts showed antitumor activity in different concentrations (IC50 = 13.55 to> 200 μg / ml), depending on the extract and the cell line examined. On the basis of the obtained results, it can be assumed that the species of lichens of Cladonia subulata, Pleurosticta acetabulum and Physcia semipinnata can find their potential application in the medical, pharmaceutical, food and cosmetic industries, as well as in the development of new phytopharmaceuticals, in the future. Manojlović, Nedeljko, 1966- Milovanović, Dragan, 1967- Vasiljević, Perica, 1972- Milovanović, Marija. 2019 2019 2019 2019 2019 2019 baccalaureate Dissertation V, 161 list 5216191 bytes o:1122 ID=524951957 ; D-3250 thesis:6697 cobiss:524951957 https://phaidrakg.kg.ac.rs/o:1122 Thesis:6697 Cobiss:524951957 srp CC BY-NC-ND 2.0 AT http://creativecommons.org/licenses/by-nc-nd/2.0/at/