Purification of Phenylalkanoids and Monoterpene Glycosides from Rhodiola rosea L. Roots by High‐speed Counter‐current Chromatography. Issue 2 (19th July 2012) - Mudge, Elizabeth
ABSTRACT: Introduction: Rhodiola rosea L. is a medicinal herb used for its adaptogenic properties. The main active components are the phenylpropanoids collectively referred to as rosavins. Objectives: To develop an isolation method for phytochemicals present in Rhodiola rosea roots using high‐speed counter‐current chromatography (HSCCC). Methodology: The roots of Rhodiola rosea were extracted with methanol and fractionated using liquid–liquid partition and polyamide column clean‐up. The purified fraction (100 mg) was subjected to semi‐preparative HSCCC using the two‐phase solvent system ethyl acetate:butanol:water (3:2:5). The head‐to‐tail elution mode was employed with a flow rate of 1.5 mL/min and a rotary speed of 1000 rpm. Results: The separation yielded six main fractions with four components more than 90% pure. The sixth fraction was further purified using semi‐preparative HPLC with a Synergi‐hydro RP C18 ‐column to obtain rosin and geranyl 1‐ O ‐α‐l ‐arabinopyranosyl(1 → 6)‐β‐d ‐glucopyranoside. The main components isolated were rosavin (3.4 mg, 97% purity), salidroside (0.5 mg, 90% purity), benzyl‐ O ‐β‐d ‐glucopyranoside (1.2 mg, 85% purity), rosarin (1.3 mg, 99% purity), rosiridin (1.8 mg, 92% purity), rosin (1.2 mg, 95% purity) and geranyl 1‐ O ‐α‐l ‐arabinopyranosyl(1 → 6)‐β‐d ‐glucopyranoside (6.5 mg, 97% purity). The identity and purity of these components were confirmed using ultrafast liquid chromatography–diode‐array detector–MS/MS analysis, 1 H‐ and 13 C‐NMR spectroscopy. Conclusion: High‐speed counter‐current chromatography was successful in the isolation of several phytochemicals present in Rhodiola rosea roots, including two components that are not commercially available. Copyright © 2012 John Wiley & Sons, Ltd. Abstract : High‐speed counter‐current chromatography was used for the isolation of phytochemicals from Rhodiola rosea L. roots. Several phenylalkanoids and monoterpene glycosides were obtained, with purities ranging from 85% to 99%. These compounds may be used as standards for quality and authenticity control and in bioassays to evaluate their pharmacological activities.