Abstract:To establish a green and highly efficient extraction process of total flavonoids from Camellia petelotii，ultrasound-assisted deep eutectic solvents （DESs） technology was employed to extract total flavonoids from Camellia petelotii. With the yield of total flavonoids as the response value，the ultrasonic-assisted DESs extraction process of total flavonoids from Camellia petelotii was optimized by combining the Plackett-Burman experiment and the Box-Behnken response surface method. The results showed that when using ethylene glycol/choline chloride as the extraction agent for DESs，the optimal extraction process was as follows：the molar ratio of ethylene glycol to choline chloride was 4∶1，the ultrasonic power was 180 W，the extraction temperature was 70 ℃，the moisture content was 40%，the liquid-to-solid ratio was 41∶1 （mL/g），and the ultrasonic time was 51 min. Under these conditions，the total flavonoid yield from Camellia petelotii was （10.65±0.26）%. The IC50 values for scavenging DPPH free radicals and ABTS+ free radicals were 32.91 and 221.5 μg/mL，respectively，which were superior to those of the methanol extract. Therefore，ultrasonic-assisted DESs can efficiently extract the total flavonoids from Camellia petelotii in a green manner.