Separation and Purification of Acetophenones from Cynanchum bengei Decne Root Bark by Combination of Silica Gel and High-speed Counter-current Chromatography

[Objectives] To develop a method for separation and purification of acetophenones from Cynanchum bengei Decne root bark by combination of silica gel and high-speed counter-current chromatography( HSCCC). [Methods]The crude extract of Cynanchum bengei Decne root bark was separated by silica gel column chromatography,and parts A and B containing acetophenones were obtained. Then,parts A and B were separated by HSCCC with a two-phase solvent system composed of petroleum ether-ethyl acetate-methanol-water( 4∶ 6∶ 4. 5∶ 5. 5 and4∶ 6 ∶ 3 ∶ 7, V/V), respectively. [Results] From 260 mg of part A, four compounds with p-dihydroxybenzene 3. 9 mg(Ⅰ),4-hydroxyacetophenone 17. 1 mg( Ⅱ),2,5-di-hydroxyacetophenone 13. 3 mg(Ⅲ) and 2,4-dihydroxyaceto-phenone 21. 0 mg(Ⅳ) were obtained. And from 300 mg of part B,136 mg of Radix Cynanchi Bungei benzophenone(Ⅴ) was obtained. The purity of compounds determined by HPLC was 97. 0%,96. 6%,99. 2%,99. 7%,99. 5%,respectively. [Conclusions] The established method is simple and efficient. It can be used for separation of acetophenones from Cynanchum bengei Decne root bark and has better practical value,which could provide a reference basis for development and utilization of Cynanchum bengei Decne root bark.

Isolation and Purification of Isoaloeresin D and Aloin from Aloe vera by High-speed Counter-current Chromatography

Objective To develop an efficient method to isolate and purify the main components isoaloeresin D and aloin from Aloe vera for its industrial production.Methods High-speed counter-current chromatography was used to isolate isoaloeresin D and aloin in a one-step separation from dried crude extract of A.vera.The biphasic solvent system composed of hexane-ethyl acetate-acetone-water(0.2:5:1.5:5) was used at a flow rate of 1.0 mL/min,while the lipophilic phase was selected as the mobile phase and the apparatus was rotated at 840 r/min.The effluent was detected at 254 nm.Results Isoaloeresin D(53.1 mg) and aloin(106.9 mg) were separated from the crude extract(384.7 mg) with the purities of 98.6% and 99.5%,respectively.Conclusion HSCCC is a powerful technique for isolation and separation of chemical composition from aloe.

Preparative Separation of Four Alkaloids from Gelsemium elegans by High-speed Counter-current Chromatography

Objective To develop an efficient preparative method for the separation of Gelsemium alkaloids from Gelsemium elegans. Methods High-speed counter-current chromatography （HSCCC） with several two-phase solvent systems was investigated for the separation of Gelsemium alkaloids. The purity and structure identification of the purified compounds were performed with HPLC and NMR spectra, respectively. Results In a single operation, 206.6 mg of crude alkaloid sample was separated to yield 28.7 mg of koumine, 24.9 mg of gelsemine, 26.9 mg of humantenine, and 7.2 mg of gelsevirine, with the purities of 97.8%, 95.4%, 97.4%, and 93.5%, respectively. Conclusion A preparative HSCCC method is successfully established for the separation of four Gelsemium alkaloids from G. elegans with a modified two-phase solvent system com posed of n-hexane-ethyl acetate-ethanol-O. 5% triethylamine-H2O （3：5：3：4）.

Extraction and purification of ustiloxin A from rice false smut balls by a combination of macroporous resin and high-speed countercurrent chromatography

Rice false smut is an emerging plant disease worldwide.Ustiloxin A(UstA)is the major mycotoxin found in rice false smut balls,which are fungal colonies in rice florets.In this study,a new method consisting of macroporous resin column chromatography and high-speed countercurrent chromatography(HSCCC)was developed for UstA separation.UstA was extracted by a 3.81%HCOOH solution and adsorbed by XAD-4 resin.UstA was then eluted by a 40%methanol solution supplemented with 0.1%trifluoroacetic acid(TFA).Further purification was achieved by HSCCC using a two-phase solvent system consisting of n-butanol/TFA/H_(2)O(1/0.05/1,v/v/v).Under the optimized conditions,225 mg of UstA was obtained with a purity of 97.39%in a single run,with a final recovery of 65.2%.An inhibitory effect on seed germination of wheat and maize caused by UstA was observed in a preliminary phytotoxicity assay.

Isolation and Purification of Triptolide from the Leaves of Tripterygium wilfordii Hook F

Triptolide is an important active component of Tripterygium wilfordii Hook F (TWHF) and possesses anti-inflammatory, immunosuppressive, male anti-fertility, and anticancer properties. A new method combining different techniques, including solid-liquid extraction, liquid-liquid partition, column chromatography and high-speed counter-current chromatography (HSCCC) but avoiding the use of chloroform, was developed for the isolation and purification of triptolide from the leaves of TWHF. 48 mg of triptolide at 96.5% purity was obtained from 1 kg of air-dried leaves of TWHF.