title: Rapid and efficient purification of chrysophanol in Rheum Palmatum LINN by supercritical fluid extraction coupled with preparative liquid chromatography in tandem.
abstract: Chrysophanol has high pharmaceutical values. However, it was difficult to use the traditional extraction method to extract high-concentration chrysophanol. Therefore, the purpose of this study is to purify and separate chrysophanol in traditional herb, Rheum Palmatum LINN, by using supercritical fluid extraction (SFE) and preparative high-performance liquid chromatography (P-HPLC) for rapid and large-scale isolation. The method is efficient for selective extraction of chrysophanol from the herbs, which have complex compositions. The extraction efficiency of chrysophanol with SFE is 25 × higher than that of boiled water extraction under the same extraction time. The optimal conditions for SFE were 210 atm and 85 °C for 30 min; for P-HPLC, a C18 column was used with a gradient elution of methanol and 1% acetic acid at a flow rate of 10 mL/min. According to (1)H NMR and LC-MS analyses, the purity of the isolated chrysophanol was as high as 99%. The recovery for chrysophanol in Rheum after SPE/PHPLC processing was in the range of 88-91.5%. Compared with other extraction and purification methods, the sequential system (SFE/P-HPLC) achieved the highest amount of extracted chrysophanol from Rheum Palmatum LINN (0.38 mg/g) and the shortest run time (3h). Hence, this rapid and environmentally friendly method can separate compounds based on polarity with high efficiencies and, coupled with P-HPLC, it may be applicable in the large-scale production of foods and medicines in the future.
authors.affiliation: Department of Biological Science and Technology, National Chiao Tung University, 75 Po-Ai Street, Hsinchu 300, Taiwan, ROC.
authors.forename: Tiffany Chien-Ting
authors.initials: TC
authors.lastname: Lo
authors.forename: Hung-Chi
authors.initials: HC
authors.lastname: Nian
authors.forename: Kong-Hwa
authors.initials: KH
authors.lastname: Chiu
authors.forename: Ai-Yih
authors.initials: AY
authors.lastname: Wang
authors.forename: Ben-Zen
authors.initials: BZ
authors.lastname: Wu
mesh_terms: D000880:Anthraquinones / Q000302:isolation & purification*; D002366:Cassia / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D025924:Chromatography, Supercritical Fluid / Q000379:methods*; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D015203:Reproducibility of Results; D012250:Rheum / Q000737:chemistry*
chemical_list: D000880:Anthraquinones; D004365:Drugs, Chinese Herbal; C027113:chrysophanic acid