Study on Extraction Process of Total Flavonoids from Forsythia suspensa by Deep Eutectic Solvents Method
In order to explore optimum extraction process of total flavonoids from Forsythia suspensa,total flavo-noids from different parts of F.suspensa(leaves,fruits and stems)were extracted by deep eutectic solvents(DESs)method.Different combinations of DESs were configured with choline chloride as hydrogen-bond acceptor and urea,ethylene glycol,glycerol,citric acid,glucose,1,2-propanediol and sorbitol as hydrogen-bond donors re-spectively,and extraction rates of total flavonoids by different combinations were determined.Response surface method was employed to confirm optimum extraction process by adjusting molar ratio of DESs,water content of DESs,liquid-solid ratio,extraction time and extraction temperature as single factor variables,and extraction rate of total flavonoids as evaluation index.Results showed that combination of choline chloride/glycerol had the highest extraction rate of total flavonoids.Content of total flavonoids in F.suspensa fruits was the highest,followed by F.suspensa leaves.Content of total flavonoids in F.suspensa stems was the lowest.The optimum ex-traction process of total flavonoids optimized by response surface method was molar ratio of choline chloride/glycerol 1∶2,water content of DESs 21%,liquid-solid ratio 35 mL/g,extraction time 125 min and extraction temperature 70℃.It was feasible to extract total flavonoids from different parts of F.suspensa by DESs method,which could provide theoretical and experimental supports for extraction and deep development of total flavo-noids from F.suspensa.
total flavonoidsdeep eutectic solventresponse surface methodextraction processForsythia suspensa