Study on the Supercritical Fluid CO_(2) Extraction of Oleanolic Acid from Hemsleya Chinensis Cogn.

Orthogonal experiments were used to optimize technics of supercritical fluid CO_(2) extraction of oleanolic acid from Hemsleya chinensis Cogn..The effects of pressure,temperature,time,CO_(2) flux,type and volume of entrainer on yield of oleanolic acid were studied.The best conditions of supercritical fluid CO_(2) extraction were as follows: pressure 40 MPa,at 55℃ for 2 h,the dosage of absolute ethyl alcohol as entrainer was 5%, and flux of CO_(2) was 20 kg·h~(-1).The method was simple,safe,selective and efficient when compared with traditional methods.