Isolation and characterization of biologically active glycosides from endemic Cephalaria species in Anatolia

Chemical constituents of the aerial parts of four endemic Cephalaria species (Dipsacaceae) in Anatolia, C. scoparia, C. paphlagonica, C. isaurica and C. stellipilis, were investigated. Two new triterpene glycosides from C. scoparia, namely scoposides F (1) and G (2), along with 11 known compounds including phenolic, flavonoid, iridoid and triterpene-type glycosides were isolated from these species. The structures of all compounds were elucidated on the basis of spectroscopic data and chemical evidence. Antioxidant activity of the compounds was tested with CUPRAC method for the first time in addition to the DPPH by using trolox and ascorbic acid as reference antioxidants, respectively. The antimicrobial activity was assessed by MIC assay and the results were given as MIC (mu g/mL) values. New triterpene glycosides scoposides F-G (1 and 2) and the compounds paphlagonoside A (6), paphlagonoside B (7) and isacoside (9), which were not tested previously, exhibited as strong antibacterial activity against Gram (+) and Gram ( ) bacteria. (C) 2011 Phytochemical Society of Europe. Published by Elsevier B. V. All rights reserved.