Flavonoids of Cirsium vlassovianum (Asteraceae)

Currently, special attention is paid to plants of the genus Cirsium Mill. (Asteraceae) used in traditional medicine as medicinal raw materials with antibacterial, nootropic and anti-inflammatory properties. In addition, Cirsium species are used in folk medicine as anti-ulcer and vulnerary agents. The therapeutic properties of these plants are due to the content of phenolic compounds, especially flavonoids. Cirsium vlassovianum Fisch. ex DC., is one of the poorly studied plants growing in the Russian Far East, the flavonoid composition of which has not been examined. Three flavonoids were isolated from the aboveground part of C. vlassovianum by extraction, column chromatography, and RP-HPLC methods: hispidulin (1), hispidulin-7-O-β-glucopyranoside (2), and pectolinarin (3). The structure of the isolated compounds was confirmed by NMR-spectroscopy. By the method of RP-HPLC—MS/MS in the initial alcoholic extract of C. vlassovianum, six more flavonoids were identified: rutin (4), cynaroside (5), apigenin-7-O-β-glucuronopyranoside (6), apigenin (7), kaempferol (8), isokaempferide (9). Therefore, this plant can be a promising source of biologically active compounds.