Background::
Scutellariae Radix, one of the most widely used herbs in Traditional Chinese
Medicine, exhibits various biological activities due to its chemical components, which stand out
for a number of flavonoids. In this study, Ultrasound-assisted aqueous two-phase extraction (UAATPE)
was employed for the first time to obtain a high extraction rate and high purity of flavonoids
from Scutellariae Radix.
Methods::
The Box-Behnken response surface method (RSM) was utilized to optimize the extraction
conditions with the application of the new aqueous two-phase system (ATPS) composed of ethanol
and ammonium sulfate. The major influence factors, including ethanol concentration, ammonium
sulfate concentration, liquid-to-solid ratio, sonication time, and extraction temperature, were investigated
by the single-factor experiment. The compositional characterization of flavonoids was characterized
with HPLC-UV. Scanning electron microscopy (SEM) was applied to research the surface
morphology of raw material. Furthermore, the bioactivities of the extract obtained by UA-ATPE
were studied in vitro.
Results::
The optimal extraction conditions were as follows: the ethanol content was 26.12% (w/w),
the ammonium sulfate content was 20.02% (w/w), the liquid-to-solid ratio was 40 mL/g, the sonication
time was 5 min with the ultrasonic power of 250 W, and the operating process was performed
at room temperature. Compared with the traditional extraction methods, UA-ATPE exhibited higher
extraction efficiency and better extraction selectivity. The DPPH and ABTS radical scavenging tests
showed that enriched products possessed strong antioxidant activity.
Conclusion::
The study confirmed that the developed method of UA-ATPE could be used as an efficient,
eco-friendly, and low-consumption method for the extraction and purification of flavonoids
from Scutellariae Radix.
