Ultrasonic Assisted Deep Eutectic Solvent Extraction Of Flavonoids From Hovenia Dulcis Thunb

Objective:in this paper,the ultrasound-assisted Deep eutectic solvents extraction of flavonoids（dihydromyricetin,eriocitrin,quercitrin,myricetin）from Hovenia dulcis Thunb.,and the optimal extraction process and antioxidant activity of flavonoids in DES were studied.Method:（1）The HPLC conditions for the determination of four flavonoids in Hovenia dulcis Thunb.were established.（2）The influence of the composition,water content,liquid-to-solid ratio,ultrasonic time,and ultrasonic temperature of the eutectic solvent on the extraction rate of Hovenia dulcis Thunb.flavonoids was investigated by the single factor and response surface design method.（3）AB-8 type macroporous resin was used to enrich and separate the flavonoids extracted from DESs.Calculate the recovery rate,and use the ABTS method and DPPH method to determine the antioxidant activity of flavonoids extracted from the DESs.Result:（1）Optimal chromatographic conditions:Column:Luna C18（250 mm×4.6 mm,5μm）,flow rate:0.6 m L/min,column temperature:30℃,detection wavelength:352 nm,injection volume:10μL,mobile phase:0.1%Aqueous for Formic acid（A）-acetonitrile（B）,elution conditions:（0–5 min,8%B;5–15 min,8–16%B;15–20 min,16-20%B;20–25 min,20–22%B;25–30 min,22-28%B;30–55 min,28–80%B;55–58 min,80-85%B）（2）The best eutectic solvent extracti on parameters:Choline chloride/1,4-butanediol with 23%water content（molar ra tio 1:3）as the extraction solvent,ultrasonic temperature 60℃ultrasonic,time 40min,liquid-solid ratio is 25:3.Under the optimal conditions,the extraction yield of dihydromyricetin,eriocitrin,quercitrin,myricetin was 0.82 mg/g,0.31 mg/g,0.02mg/g and 0.008 mg/g.（3）The results showed that the recoveries of dihydromy ricetin,eriocitrin,quercitrin,and myricetin were 86.46%,77.27%,76.46%and 72.86%.The IC₅₀of DPPH and ABTS were 0.085 mg/m L and 0.028 mg/m L respect ively.Conclusion:dihydromyricetin,eriocitrin,quercitrin,myricetin in Hovenia dulcis Thunb.can be extracted quickly and effectively by using ultrasound-assisted Deep eutectic solvents,and macroporous resin can directly enrich and separate the flavonoids extracted by eutectic solvent,obtain the extract with strong antioxidant activity.This paper provides experience and reference for the future utilization and development of Hovenia dulcis Thunb.