Introduction– The official rhubarb species have frequently been investigated for their hydroxyanthraquinone components and associated pharmacological properties. However, other unofficial rhubarb specieswere rarely studied until polyhydroxystilbenes (PHS), which commonly occur in the unofficial rhubarb, revealed a range of potential bioactivities. Hence, there has been increasing interest in the efficient preparation of high-purity PHS for pharmacological and clinical trials.
Objective– To develop a suitable method for large-scale preparative separation of PHS from the rhizome of Rheum likiangense Sam. by high-speed counter-current chromatography (HSCCC).
Results– Two PHS compounds were isolated successfully within 440 min using a solvent system consisting of methanol: n-butanol:chloroform:water (2:0.5:3:3, v/v/v/v). Eighty-four milligrams of desoxyrhaponticin with 98.2% purity and 148mg of rhaponticin with 95.3% purity were respectively yielded from 1.5 g of crude extract in the single, one-step operation.
Conclusion– An optimised HSCCC method has been established for large-scale preparative separation of PHS compounds from Rheum likiangense Sam. Copyright © 2012 John Wiley & Sons, Ltd.
Figure 3. HSCCC chromatogram of crude extract from Rheum likiangense Sam.Solvent systems:
methanol:n-butanol:chloroform:water (2:0.5:3:3); revolution speed: 480 rpm; flow rate: 25mL/min; temperature: 25 _C; mode: forward rotation (0–300min),
reverse rotation (300–440min); retention of the stationary phase: 59%; 1.5 g crude extract; detection wavelength: 313nm; fraction I: desoxyrhaponticin; fraction II: rhaponticin.
1. Author Information:Xiaoyan Wang, Honglun Wang, Chenxu Ding and Yourui Suo
Correspondence: E-mail:suo_yourui@163.com
2. Published : Phytochem. Anal. 2012, 23, 684–688