Phytochemical investigation of Cirsium creticum (Lam.) d'Urv. subsp. creticum (Asteraceae) plant which growing in Trakya region and determination of its antioxidant activity

The aim of this study is to examination the phytochemical analysis of Cirsium creticum Lam.) d'Urv. subsp. creticum (Asteraceae) plant, which was grown in the Trakya region, whose chemical content and biological activity have not been investigated before, especially isolation of new phenolic / flavonoid compounds and determination of chemical structures of these compounds. For this purpose, plants were extracted by using methanol, diethyl ether, n-hexane, ethylacetate as solvent. Total phenolic / flavonoid content was determined in crude extracts and DPPH radical scavenging activitiy, ABTS•+ cation radical scavenging activitiy, FRAP capacity, β-carotene bleachingactivitiy, CUPRAC and superoxide anion radical scavange activitiy methods applied for determination of antioxidant activity in crude extracts. As a result of this study; MeOH extract was revealed higher total phenolic/flavonoid content than the other extracts. According to antioxidant activity assays MeOH extract had highest antioxidant activity except superoxide anion radical scavange activitiy and CUPRAC activity. In the determination of antioxidant activity (except Superoxide and CUPRAC methods) MeOH extract was gave the best result. Therefore meOH extract was chosen for the isolation study and substances were separated by chromatographic methods and chemical structures were determined by 1D, 2D NMR and MS techniques. As a result of the work, 7 compounds including 5 alkyl phenol, 1 phthalic ester and 1 phenolic acid derivative were isolated from C. creticum plant. ABTS•+ scavenging activity and ferric-reducing antioxidant power (FRAP) applied to isolated compounds which are identified as 2,3 and 4 alkyl phenol derivates. The seven isolated compounds were first isolated from C. creticum plant. Antioxidant activity tests were applied to 2,3 and 4 alkyl phenol derivates which are isolated. ABTS•+ scavenging activity, CUPRAC and ferric-reducing antioxidant power (FRAP) of 2 numbered compound was found highest antioxidant activity. Keywords: Cirsium creticum, Asteraceae, alkyl phenols, antioxidant activity, total phenolic content, phenolic acid, alkyl catechol 2018, 180 Pages