Novel flavones in Lamium L. genus

• Author(s): Pereira, Olívia R. ; Domingues, M.R.M. ; Silva, Artur M.S. ; Cardoso, Susana M.
• Date: 2012
• Persistent ID: http://hdl.handle.net/10198/8269
• Origin: Biblioteca Digital do IPB
• Subject(s): Lamium L.; Isoscutellarein derivatives; HPLC-DAD; ESI-MSn; RMN
• Document Type: Conference Object
• Language: English

Description

The main aim of this work is to determine the phenolic composition of a Lamium album L. purified extract, in order to contribute for the chemical characterization of this plant. Moreover, it also intends to emphasize its antioxidant properties. As established by HPLC-DAD and ESI-MSn combined analysis, verbascoside was the major phenolic constituent of Lamium album L. purified extract, as previously described by other authors [1]. Still, we could also detect, for the first time in Lamium genus, significant amounts of isobervascoside and of isoscutellarein derivatives. As confirmed by NMR analysis, the major isoscutellarein derivative in Lamium album L. purified extract was the isoscutellarein-7-O-(6-O-acetyl-β-allosyl)(1→2)-β-glucoside, but isoscutellarein-7-O-allosyl(1→2)glucoside and of O-methyl derivatives of these two compounds were also present in considerable amounts. Aditionally, the extract showed good antioxidant activities in in vitro experiments. Overall, the present study contributes for the chemical and biological characterization of L. album L.