Comparison of modified ultrasound-assisted and traditional extraction methods for the extraction of baicalin and baicalein from Radix Scutellariae

An attempt was made in this study to extract baicalin and baicalein from Radix Scutellariae using modified ultrasound-assisted extraction (UAE), and these results were compared to a commonly used heat reflux extraction (HRE) procedure. The best results were obtained when working at an ultrasonic frequency of 40 kHz, a power of 185 W, an ultrasound cycle of 79% (intermittent sonication), a mean particle size of 0.355 mm, a ratio of solvent to raw material of 10:1 (mL/g), an extraction time of 20 min and three cycles. The optimum extraction temperature and ethanol concentration differ for different flavanone compounds. The extraction of baicalin and baicalein were most efficient at temperatures of 60 and 30 °C, respectively, with ethanol concentrations of 40 and 50% (v/v), respectively. Compared with HRE, the modified UAE method reduced the extraction time, the extraction temperature and the solvent consumption. Moreover, UAE achieved superior baicalin and baicalein yields, is a potential method for industry.

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► A modified UAE was used to extract the bioactive flavonoids from Radix Scutellariae.
► Under optimal process, a higher yield was obtained with UAE than with HRE method.
► UAE can be carried out at lower extraction temperature, time and solvent consumption.
► UAE is efficient for the industries of food, pharmacy and environmental engineering.