Optimization of ultrasound-assisted extraction of camptothecin from Camptotheca acuminata seeds

Abstract

Naturally occurring camptothecin (CPT) is an important source of chemotherapeutic agents. The extraction from Camptotheca acuminata is still the main approach to obtain CPT compared with total synthesis. In the present study, ultrasound-assisted extractions (UAE) of CPT from C. acuminata seeds with alkaline solutions were investigated and CPT yield were determined by High Performance Liquid Chromatography. The conditions of alkaline species and concentrations, extraction time, extraction temperature and ultrasonic power were optimized. Results show that both Na₃PO₄ and Na₂CO₃ solutions gain good extraction yields, whereas Na₃PO₄ solution has stronger basicity and need higher concentration than Na₂CO₃ solution does, thus aqueous Na₂CO₃ is more beneficial for the extraction. The optimal condition was ultrasonically extracted with 0.5% aqueous Na₂CO₃ at 50°C and ultrasonic power of 400 W for 60 min. Comparing with UAE with ethanol, the extraction with 0.5% Na₂CO₃ solution achieves higher yield. Moreover, aqueous Na₂CO₃ as a solvent has various advantages including non-toxicity, inflammable, non-corrosive and low cost, which ensure this UAE method is a superior method with high utilizing prospect.

Keywords

camptothecin / Camptotheca acuminata / ultrasound-assistant extraction

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