Novel acetylated chalcone and biflavonoid glycosides from Trigonosciadium brachytaenium (Boiss.) Alava.

A new acetylated chalcone glycoside, trans-2′,6′-dihydroxy-4′-O-(4″-acetyl-rhamnoside)-4-methoxychalcone (1) and a new biflavonoid glycosides, 5,3′,5″,4″′-tetrahydroxy-3″′,5″′dimethoxy-biflavone (4′ → 8″)-7-O-((2-rhamnoside) rhamnoside) (2) were isolated from the ethyl acetate soluble fraction of the methanol extract obtained from Trigonosciadium brachytaenium and have been purified by column chromatography and preparative TLC. Those structures were elucidated by UV, ¹H NMR and ¹³C NMR, HMBC, EI-MS and IR spectra. The antioxidant activity of ethyl acetate extract was evaluated by 1,1-diphenyl-2-picrylhydrazyl method. The results indicate that ethyl acetate extract from aerial part of T. brachytaenium possesses considerable antioxidant activity. [ABSTRACT FROM AUTHOR]