ABSTRACT
OBJECTIVE：To optimize ultrasonic-assisted ethanol-（NH4）2SO4 aqueous two-phase extraction technology of citru- sinol from Desmodium caudatum . METHODS ：Using the content of citrusinol as indexes ，with ethanol volume fraction ， solid-liquid ratio ，（NH4）2SO4 addition amount ，ultrasonic time and ultrasonic temperature as factors ，based on the single factor tests，Box-Behnken design-response surface methodology was used to optimize the extraction technology of citrusinol. RESULTS ： The optimized extraction technology of citrusinol included that ethanol volume fraction was 95.35％，the solid-liquid ratio was 1∶50.35 （g/mL），（NH4）2SO4 addition amount was 4.49 g，ultrasonic time was 48.7 min，ultrasonic temperature was 57.6 ℃. In 3 times of validation tests ，the extraction rates of citrusinol were 0.637 8，0.638 4，0.625 4 mg/g，respectively，which was close to predicted value（0.630 5 mg/g）. CONCLUSIONS ：The optimized ultrasonic-assisted ethanol- （NH4）2SO4 aqueous two-phase extraction technology is stable and feasible ，and can be used for the extraction of citrusinol from D. caudatum .
ABSTRACT
AIM To optimize the two-phase (ethanol-dipotassium phosphate) aqueous extraction for Astragali Radix by central composite design-response surface method.METHODS With ethanol concentration,dipotassium hydrogen phosphate solution concentration and Astragali Radix feed ratio as influencing factors,together with extraction rates of total flavonoids and total saponins as evaluation indices,the technology optimization was accomplished by central composite design-response surface method.RESULTS The optimal conditions were determined to be 27.97％ for ethanol concentration,22.03％ for dipotassium hydrogen phosphate solution concentration,and 1 ∶ 58.85 for Astragali Radix feed ratio.The extraction rate of total flavonoids reached 74.13％ (concentrated in the upper layer),while that of total saponins reached 81.34％ (concentrated in the lower layer).CONCLUSION With good predictability,this simple and accurate method can be used for the extraction of total flavonoids and total saponins in Astragali Radix.
ABSTRACT
AIM:To explore the extraction mechanism of the separation-purification of baicalin in aqueous two-phase systems. METHODS:By experiment,nonionic surfactant PEG-K_2PHO_4-H_2O two aqueous phase system was selected to phase-forming conditions,and the effect of temperature,pH,salt composition on partition of baicalin PEG/salt system. RESULTS:The extraction rate of baicalin in aqueous two-phase system was up to 98.6%. CONCLUSION:The two aqueous phase system for baicalin extraction is easy to operate has good reproductivity,and can be applied in mass production.