Development of an ionic liquid-based ultrasonic/microwave-assisted simultaneous distillation and extraction method for separation of camptothecin, 10-hydroxycamptothecin, vincoside-lactam, and essential oils from the fruits of Camptotheca acuminata Decne

Abstract

An ionic liquid-based ultrasonic/microwave-assisted simultaneous distillation and extraction (IL-UMASDE) method for isolating camptothecin (CPT), 10-hydroxycamptothecin (HCPT), vincoside-lactam (VCS-LT), and essential oils (EOs) from Camptotheca acuminata Decne fruits was developed. The important parameters were optimized using single-factor and central composite design experiments. The optimum conditions were 0.75 M 1-octyl-3-methylimidazolium ([C8mim]Br) as the extraction solvent, a liquid-solid ratio of 13.7 mL/g, an extraction time of 33.2 min, a microwave power of 582W, and a fixed ultrasonic power of 50W. The yields of CPT, HCPT, and VCS-LT obtained under the optimum conditions were 2.463, 0.164, and 0.297 mg/g, respectively; these are 1.08-, 1.12-, and 1.04-fold higher, respectively, than those obtained by conventional 55% ethanol heat reflux extraction (HRE). The extraction time for the equilibrium yields of CPT, HCPT and VCS-LT using IL-UMASDE was 33.6%, 58.5%, 63.1%, and 66.8%, respectively, less than the corresponding times using IL-MASDE, IL-ultrasonic-assisted extraction (IL-UAE), 55% ethanol UAE and 55% ethanol HRE. The yield of EOs obtained using IL-UMASDE was 0.793 mg/g, i.e., 1.31-fold higher than that obtained by conventional hydrodistillation extraction (HDE). The components of the EOs obtained using IL-UMASDE and HDE were similar. The extraction time for the equilibrium yields of EOs using IL-UMASDE is 33.6%, 58.5%, 52.6%, and 72.3% lower than those for IL-MASDE, water-UMASDE, water-MASDE, and HDE, respectively. Compared with other extraction methods, IL-UMASDE gave the highest yields of CPT, HCPT, VCS-LT, and EOs and also had the shortest extraction time. IL-UMASDE is a potential green and highly efficient technique for the extraction of CPT, HCPT, VCS-LT, and EOs from Camptotheca acuminata Decne fruits.