A novel and efficient ultrasonic assisted-reflux synergistic extraction (UARSE) method for extracting camptothecin (CPT) and betulinic acid (BA) from Camptotheca acuminata Decne. fruits has been developed in this study. The advantages of the ultrasonic and reflux extraction methods have been combined in the UARSE method and used to extract CPT and BA for the first time. The parameters influencing the efficiency of UARSE were optimized using the Box-Behnken design (BBD) to obtain the maximum extraction yield of CPT and BA. The optimal extraction conditions were as follows: 225 W for the ultrasonic power; 24 min for the extraction time; and 32 mL/g for the liquid-solid ratio. The extraction yields obtained by UARSE were 2.386 ± 0.112 mg/g for CPT and 17.192 ± 0.808 mg/g for BA, which were 1.43-fold and 1.33-fold, respectively, higher than by using heating reflux extraction (HRE) and ultrasonic-assisted extraction (UAE). In addition, the 24-min extraction time using UARSE was 80% and 60% less than those provided by HRE and UAE, respectively. Therefore, UARSE can be considered a rapid and efficient method for extracting CPT and BA from the fruits of C. acuminata Decne.
Keywords: BA; CPT; Camptotheca acuminata Decne.; UARSE.