Method of extracting myricetin from Xanthoceras sorbifolia Bunge

A method of extracting myricetin from Xanthoceras sorbifolia Bunge, the method comprising:

• step 1, baking Xanthoceras sorbifolia Bunge, crushing the baked Xanthoceras sorbifolia Bunge, and sieving the crushed Xanthoceras sorbifolia Bunge to obtain a crude powder;
• step 2, mixing the crude powder with a counter-current extraction solution to perform a counter-current extraction at a low temperature to obtain a filtrate and a filter residue, a mass ratio of the crude powder to the counter-current extraction solution being 1:100 to 1:500, the counter-current extraction solution comprising sucrose ester, sulfonated castor oil and ethanol at a mass ratio of 4:1:500 to 4:1:1000, the low temperature being 25° C. to 35° C., wherein the counter-current extraction is conducted for 20 minutes (min) to 40 min;
• step 3, mixing the filter residue with a solvent to obtain a first mixture, and heating the first mixture to reflux for extraction for 1 to 3 times to obtain an extraction liquid;
• step 4, mixing the extraction liquid obtained in step 3 and the filtrate obtained in step 2 to obtain a second mixture, adding an alkaline auxiliary agent to the second mixture to obtain a third mixture, and adjusting a pH of the third mixture to 8-9;
• heating to boil the third mixture after adjusting the pH to obtain a boiling mixture, reducing a temperature of the boiling mixture to room temperature, and concentrating under reduced pressure to obtain a concentrated solution, the alkaline auxiliary agent being saccharin sodium;
• and
• step 5, separating and eluting the concentrated solution with a monohydric alcohol aqueous solution in a macroporous adsorption resin to obtain an eluent, then drying the eluent to obtain the myricetin.