Extraction of flavonoids from Glycyrrhiza residues using deep eutectic solvents and its molecular mechanism

•Fourteen deep eutectic solvents (DESs) were used to extract flavonoids from Glycyrrhiza residues.•ChCl-glycolic acid had the greatest capacity for extracting four flavonoids.•Optimal extraction rate was 83.03% higher than that using 60% ethanol.•Molecular mechanism associated with DES-flavonoid interactions were analyzed.•Hydrogen bond strength was significant for the DES-flavonoid extraction process.