Concurrent Extraction and Purification of Gentiopicroside from Gentiana scabra Bunge Using Microwave-Assisted Ethanol-Salt Aqueous Two-Phase Systems.

A potential method called microwave-assisted aqueous two-phase extraction (MA-ATPE) was developed for concurrent extraction and purification of gentiopicroside from Gentiana scabra Bunge. Formation characteristics of aqueous two-phase system (ATPS) composed of ethanol and 25 kinds of salts were investigated; K2HPO4 (w/w, 21.71%) and ethanol (w/w, 40.72%) were determined to be the optimal compositions of ATPS. Response surface methodology based on Box-Behnken design was used to investigate the extraction conditions, the optimal parameters were summarized as follows: 80°C of extraction temperature, 31 s of extraction time, 11:1 (mL/g) of liquid-to-solid ratio, 100 meshes of particle size and 806 W of microwave power. Under these conditions, the extraction yield of gentiopicroside was 65.32 ± 0.24 mg/g with a recovery of 96.51%. Compared with other four methods, the purity of gentiopicroside in the crude extracts reached 17.16 ± 0.25%, which was significantly higher than that of smashing tissue extraction, microwave assisted-extraction, ultrasonic-assisted extraction and heat reflux extraction, respectively. In addition, the phase-forming salt can be recyclable. Therefore, MA-ATPE was an excellent and alternative technique to the conventional extraction approaches of gentiopicroside.

[Study on extraction process of total flavonoids in Herba Desmodii Styracifolii].

OBJECTIVE: To study the optimum extraction process of total flavonoids in Herba Desmodii Styracifolii. METHODS: Using the extraction yield of total flavonoids as the assessment index, some important factors in the experimental orthogonal design, such as volume of extraction water, extracting time and times, alcohol concentration were studied. The total flavonoids content extracted from Herba Desmodii Styracifolii was determined by Spectrophotometric method at 272 nm wavelength. RESULTS: The optimum ethanol extracting process conditions were as follows: adding 15 fold of water extracting three times, heating for 1.5 hours, the use of alcohol concentration of 50%. Rutin standard sample showed a good linear relationship at the range of 4.36 - 21.8 microg/ml and the average recovery was 98.92%, and RSD was 1.85%. CONCLUSION: The optimum extraction process of total flavonoids in Herba Desmodii Styracifolii is reliable and this method is easy and accurate so that it can be used for the extraction of total flavonoids in Herba Desmodii Styracifolii.