Separation of Two Cytotoxic Saponins from the Roots of Adenophora triphylla var. japonica by High-speed Counter-current Chromatography
Correspondence to: Yeong Shik Kim, Natural Products Research Institute, College of Pharmacy, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 151-742, Korea. E-mail: firstname.lastname@example.org
The roots of Adenophorae species have been reported to exhibit anti-obese, anti-oxidant, anti-cancer, and anti-bacterial activities. However, there has been no single report regarding the preparative isolation and biological activities of the chemical components from Adenophora triphylla.
To develop an efficient method for the determination of the active fraction from the methanol extract from the roots of Adenophora triphylla and for the preparative isolation and purification of target compounds having cytotoxicity on carcinoma cells from the active fraction by high-speed counter-current chromatography (HSCCC).
The Plant (5 kg, dry weight) was extracted with methanol. Three hundred grams of the dried methanol extract (885 g) were fractionated by open-column chromatography with a stepwise gradient of water–methanol. Preparative isolation of bioactive components was performed by HSCCC with a two-phase solvent system composed of ethyl acetate-n-butanol–0.2% trifluoroacetic acid in water (5:5:10, v/v). The cytotoxicity of column fractions and isolated compounds was evaluated by 2-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay.
The 70% MeOH column fraction showed inhibitory effects against three human carcinoma cells A549, AGS and HepG2. Two saponins were separated from 400 mg of the active fraction by HSCCC. After further purification with solid phase extraction column, 25 mg of peak fraction 1 and 20 mg of peak fraction 2 were obtained. Their structures were identified by 1 H-NMR, 13C-NMR, Fourier transform infrared, fast atom bombardment–MS and electrospray ionisation–MS/MS. They exhibited strong cytotoxic effects against three cancer cells.
Two cytotoxic saponins were isolated for the first time from the roots of Adenophora triphylla by HSCCC. Copyright © 2012 John Wiley & Sons, Ltd.