Purification of lignans from Schisandra chinensis fruit by using column fractionation and supercritical antisolvent precipitation.

This study examined the use of ultrasonic-assisted extraction (UAE) coupled with column chromatography (CC) and supercritical antisolvent (SAS) precipitation in purifying five lignans from the dried fruit of Schisandra chinensis. Column fractionation of the ultrasonic extracts and SAS precipitation of the column elution resulted in a ten- and three-fold increase of the five lignans, respectively. Experimental data showed that the concentrations of the five lignans increased from 26.14mgg(-1) in the extraction to 581.85mgg(-1) in the effluent after SAS precipitation with a recovery of 84%. The effluent contained 145.32mgg(-1)of schisandrol B, 56.65mgg(-1)of schisandrin A, 66.38mgg(-1) of γ-schisandrin, 266.70mgg(-1) of gomisin N, and 46.80mgg(-1)of schisandrin C. In addition, our experimental results from a response surface method designed SAS precipitations for the enhancement of the purity of the five lignans, showed that time and carbon dioxide flow rate are significant in altering the purity and the recovery. This work demonstrated that the five lignans of Schisandra chinensis were successfully purified by using the SAS process.

Production of all trans-beta-carotene by using impinging flow of supercritical carbon dioxide anti-solvent pulverization.

This work investigated column elution chromatography coupled with supercritical anti-solvent precipitation to produce carotenoid rich microsized particulates from microalgal Dunaliella salina species. The extract contained carotenoids ranging from 61.3 mg/g(salina) to 72.5 mg/g(salina) using ultrasonic stirred ethyl ether or tetrahydrofuran (THF) extraction. When 10 L of ethyl alcohol was employed to elute the THF extract, purity of trans-ß-carotene is 823.6 mg/g with a recovery of 86.2%. It was found that the supercritical anti-solvent of THF solution at 160 bar and 318 K produced powdered particulates with a purity of carotenoids above 90%. Subsequently, a central composite response surface design method was used to design supercritical anti-solvent precipitation of carotenoid-rich THF solution. This was accomplished by increasing the pressure from 140 bar to 180 bar and the time from 40 min to 60 min at a feed flow rate of 0.2 mL/min. A CO(2) flow rate of 15 L/min and a temperature of 318 K were also used to determine the effects on purity and recovery of trans-ß-carotene. The combined process produced micronized precipitates with a mean particle size ranging from 3.5 µm to 19 µm and the purity of trans-ß-carotene attained was 926.8 mg/g with a recovery of 54%.