Chemical Composition and Antioxidant Activity of Cirsium vulgare Inflorescences.

The chemical composition of Cirsium vulgare flower heads was examined. Petrol and chloroform extracts of this plant material were analyzed by GC-MS for the presence of fatty acids, phytosterols, and triterpenes. Diethyl ether, ethyl acetate, and butanol fractions of the methanolic extract were subjected to multistep - chromatographic separations, and as a result, fourteen flavonoids were obtained (1-14). All compounds were isolated from this morphological part for the first time and eleven from the plant. Among the identified components were four aglycones, eight glycosides, and two glycoside esters, derivatives of apigenin, luteolin, kaemferol, and quercetin. One of them was a rarely occurring compound apigenin 7-0-p-(6"-butyl)-glucuronide) (14). Total flavonoid content and antioxidant activity were determined in the various fractions of methanolic extract.