Tingting Liu

Study on ionic liquid-based ultrasonic-assisted extraction of biphenyl cyclooctene lignans from the fruit of Schisandra chinensis Baill

The ionic liquid-based ultrasonic-assisted extraction (ILUAE) has been successfully applied in extracting four biphenyl cyclooctene lignans from the fruit of Schisandra chinensis Baill. Seventeen different types of ionic liquids with different cations and anions have been investigated. 0.8 M 1-lauryl-3-methylimidazolium bromide ([C12mim]Br) solution was selected as solvent. In addition, the ultrasonic parameters including ultrasonic power, time for ultrasonic treatment and solid-liquid ratio have been optimized by Response Surface Method (RSM). Compared with the conventional solvent extraction, the efficiency of the approach proposed in this work is about 3.5 times as much as that of the conventional solvent extraction method. With the proposed extraction method, the extraction time has been reduced to 30 min, whereas the conventional extraction method requires about 6.0 h. The experimental results presented in this work indicate that the ILUAE is a simple and efficient technique for sample preparation. The proposed method is reproducible.

Ionic liquid-based microwave-assisted extraction of essential oil and biphenyl cyclooctene lignans from Schisandra chinensis Baill fruits.

Ionic liquid-based microwave-assisted extraction (ILMAE) has been successfully applied in extracting essential oil and four kinds of biphenyl cyclooctene lignans from Schisandra chinensis Baill. 0.25 M 1-lauryl-3-methylimidazolium bromide ionic liquid is selected as solvent. The optimum parameters of dealing with 25.0 g sample are 385 W irradiation power, 40 min microwave extraction time and 1:12 solid-liquid ratio. The yields of essential oil and lignans are 12.12±0.37 ml/kg and 250.2±38.2 mg/kg under the optimum conditions. The composition of the essential oil extracted by hydro-distillation, steam-distillation and ILMAE is analyzed by GC-MS. With ILMAE method, the energy consumption time has not only been shortened to 40 min (hydro-distillation 3.0 h for extracting essential oil and reflux extraction 4.0 h for extracting lignans, respectively), but also the extraction efficiency has been improved (extraction of lignans and distillation of essential oil at the same time) and reduces the environmental pollution. S. chinensis materials treated by different methods are observed by scanning electronic microscopy. Micrographs provide more evidence to prove that ILMAE is a better and faster method. The experimental results also indicate that ILMAE is a simple and efficient technique for sample preparation.

Optimization of conditions of solvent-free microwave extraction and study on antioxidant capacity of essential oil from Schisandra chinensis (Turcz.) Baill.

In this article, solvent-free microwave extraction (SFME) of essential oil from Schisandra chinensis (Turcz.) Baill was studied. A multivariate study based on central composite design (CCD) was used to evaluate the influence of three major variables affecting the performance of SFME. The optimum parameters were extraction time 30 min, irradiation power 385 W and moisture content of the fruits was 68%. The extraction yield of essential oil was 11 ml/kg under the optimum conditions. The antioxidant capacity of essential oils extracted by different methods were determined, and compared with traditional antioxidants. GC-MS showed the different composition of essential oil extracted by hydro-distillation (HD), steam-distillation (SD) and SFME. S. chinensis materials treated by different methods were observed by scanning electronic microscopy (SEM) and thermo-gravimetric analysis (TGA). Micrographs and thermo gravimetric loss provided more evidences to prove SFME of essential oil is more completed than HD and SD.

Development of sample preparation method for isoliquiritigenin, liquiritin, and glycyrrhizic acid analysis in licorice by ionic liquids-ultrasound based extraction and high-performance liquid chromatography detection

An ionic liquid-based ultrasonic-assisted extraction (ILUAE) method had been used for the effective extraction of isoliquiritigenin (IQ), liquiritin (LQ) and glycyrrhizic acid (GA) from licorice. The ionic liquids with different cations and anions were investigated in this work and 0.5 M 1-butyl-3-methylimidazolium bromide solution was selected as solvent. In addition, the technical parameters including soaking time, solid-liquid ratio, ultrasonic power and time were optimized. Compared with the conventional solvent extraction, the proposed approach exhibited higher efficiency, which indicated the ILUAE was an efficient, rapid and simple sample preparation technique. There was no degradation of the target analytes had been observed at the optimum conditions which was evidenced by the stability studies performed with standard of IQ, LQ and GA. The proposed method also showed high reproducibility and was environmental friendly.

Preparation of high purity biphenyl cyclooctene lignans from Schisandra extract by ion exchange resin catalytic transformation combined with macroporous resin separation

In this study, ester-bond biphenyl cyclooctene lignans were efficiently hydrolytically degraded into free biphenyl cyclooctene lignans by ion exchange resin transformation and simultaneous removal of impurities by macroporous resin. The OH-type strongly basic anion exchange resin 201×7 was the best one, and the dynamic hydrolysis efficiency was 146.7±5.0%. HPD5000 macroporous resin, which offered higher adsorption and desorption capacities and faster adsorption than other resins. The purity of free biphenyl cyclooctene lignans in the product increased from 5.14±0.24% to 79.67±0.0.67%. After dynamic catalytic transformation by 201×7 resin combined with purification of HPD5000 resin, the yield and the purity of free biphenyl cyclooctene lignans in the product were 132.1±4.7% and 80.91±3.53%, respectively.

Optimization of shikonin homogenate extraction from Arnebia euchroma using response surface methodology.

An efficient homogenate extraction technique was employed for extracting shikonin from Arnebia euchroma. The homogenate extraction procedure was optimized and compared with other conventional extraction techniques. The proposed method gave the best result with the highest extraction efficiency in the shortest extraction time. Based on single-factor experiments, a three-factor-three-level experimental design has been developed by Box-Behnken design. The optimal conditions were 78% ethanol as solvent, homogenate extraction time of 4.2 min, 10.3 liquid to solid ratio and two extraction cycles. Moreover, the proposed method was validated by stability, repeatability and recovery experiments. The developed homogenate extraction method provided a good alternative for the extraction of shikonin from A. euchroma. The results indicated that the proposed homogenate extraction was a convenient, rapid and efficient sample preparation technique and was environmental friendly. Furthermore, homogenate extraction has superiority in the extraction of thermally sensitive compounds from plant matrices.