Extraction and composition of three naturally occurring anti-cancer alkaloids in Camptotheca acuminata seed and leaf extracts.

摘要

Naturally occurring camptothecins (CPT) are important sources of chemotherapeutic agents for clinical treatment of cancer. Extraction of CPT from Camptotheca acuminata trees remains to be a cost-effective way in the supply equation compared with a total synthesis. This study conducted a series of experiments to determine efficient solvent for the maximal extraction of CPT and its two derivatives, hydroxycamptothecin (HCPT) and methoxycamptothecin, from seeds and leaves of C. acuminata. Methanol as an extraction solvent demonstrated in seeds a significantly higher recovery of these three alkaloids than dichloromethane and acetone. Methanol concentrations at 70% in water resulted in maximum extraction of all the three alkaloids regardless of the type of plant materials. However, other strengths of methanol, lower or higher, either decreased the extracting power or showed no improvement in the extraction. Seed extract contained all the three alkaloids whereas leaf extract was absent of HCPT. A stable ratio of the three alkaloids was discovered but it was dependent upon seed or leaf extract of C. acuminata, which with various compositions can be produced. Ecological and medicinal implications of the leaf and seed extract characterized with different chemical compositions are discussed.