Study on the Extraction of Ursolic Acid from Loquat Leaf Via Ultrasonic Wave

OBJECTIVE To investigate the effects of different treatment methods on extracting ursolic acid from Loquat Leaf with the aid of ultrasonic wave.METHODS After the precipitates obtained by the treatment of Loquat Leaf with different methods,ursolic acid is extracted by using ethanol as a medium under the ultrasonic wave.The content of ursolic acid is determined with HPLC method. RESULTS The content of ursolic acid in Loquat Leaf is above 0.9%.Some of ursolic acids remain in the precipitates after the different treatments.CONCLUSION Ursolic acid is almost indissoluble in water or oil;the effect of ethanol refluxing extraction is not satisfactory,even increase the extract cycle,the yield of ursolic acid will not enhance obviously;Ursolic acid in Loquat Leaf exists mainly in dissociative form.