U okviru ovoga diplomskog rada provedena je fitokemijska karakterizacija endemske vrste Centaurea ragusina L., Asteraceae. Prisutnost polifenolnih tvari dokazana je općim reakcijama stvaranja obojenih produkata ili taloga. Provedbom tankoslojne kromatografije potvrđena je prisutnost kvercetina, rutina i klorogenske kiseline u metanolnom ekstraktu dubrovačke zečine. Kvantitativna analiza ukupnih polifenola (UP), trjeslovina (T), flavonoida (F) i fenolnih kiselina (FK) provedena je spektrofotometrijskim metodama. Sadržaj analiziranih polifenolnih tvari iznosio je: 3,04±0,04% (UP), 0,36±0,04% (T), 0,25±0,00% (F) i 0,38±0,01% (FK). Provedena fitokemijska karakterizacija predstavlja prilog znanstvenom istraživanju hrvatskih endema i upotpunjuje dosadašnje spoznaje o fitoterapijskom potencijalu dubrovačke zečine, posebice u odnosu na sadržaj bioaktivnih polifenolnih tvari.

In this work, phytochemical characterization of an endemic species, Centaurea ragusina L. (Asteraceae) was carried out. The presence of polyphenols was proven by using general reactions of developing colored products and precipitates. The thin layer chromatography revealed the presence of quercetin, rutin, and chlorogenic acid in the methanolic extract. Quantitative analysis of total polyphenols (TP), tannins (T), flavonoids (F), and phenolic acids (PA) was carried out using the spectrophotometric methods. The contents of analyzed polyphenolic compounds were as follows: 3.04±0.04% (TP), 0.36±0.04% (T), 0.25±0.00% (F), and 0.38±0.01% (PA). Performed phytochemical characterization is a contribution to the scientific study of Croatian endemic species and completes the existing knowledge about phytotherapeutic potential of C. ragusina, especially in relation to the content of bioactive polyphenolic substances.