Preparation and structural identification of C-glycoside flavones compounds isolated from the leaves of Belamcanda chinensis

Using HP20 macroporous resin, polyamide, Sephadex-LH20 and YMC preparation column (ODS), four kinds of C-glycoside flavones were isolated from the leaves of Belamcanda chinensis grown in Hainan island. Combined with the measurement of melting points and chemical reactions, the structures of C-glycoside flavones were identified by analyzing the spectroscopic data of UV, ¹HNMR, ¹³CNMR, MS. They are compound I 2″-O-rhamnosylisovitexin; compound II 2″-O-rhamnosylswertisin; compound III isovitexin and compound IV swertisin. All the compounds are isolated from the Iridaceae plants for the first time.