Separation, purification and quantification of verbascoside from Penstemon barbatus (Cav.) Roth

Echinacoside and verbascoside possess a spectrum of significant beneficial bioactivities. A new method of preparative high-speed counter-current chromatography for rapid separation and purification of verbascoside from the leaves of Penstemon barbatus (Cav.) Roth was introduced. The solvent system employed here was n-butanol-water (1:1, v/v). The structure was confirmed by IR, H-1 NMR and C-13 NMR. According to the quantification results, echinacoside and verbascoside were found to be as much as 5.25 +/- 0.13 mg/g and 11.21 +/- 0.16 mg/g, respectively, in the leaves of P. barbatus. This indicates that P. barbatus might be an ideal alternative resource for large scale preparation of echinacoside and verbascoside. (C) 2012 Elsevier Ltd. All rights reserved.