An improved process for the isolation of anticancer agent camptothecin from <i>Mappia nimmoniana</i> bark using an ionic solvent that dissolves cellulose

Camptothecin, a potent anti-cancer alkaloid originally derived from <i>Camptotheca acuminata</i>, can also be efficiently extracted from the bark of <i>Mappia nimmoniana</i> (J. Graham) Byng & Stull using an innovative green chemistry method, uses an ionic liquid that dissolves cellulose. Camptothecin is the starting material for the commercial semi-synthesis of anticancer drugs topotecan and irinotecan. The described method is helpful for the commercial production of camptothecin. In this study, the ionic liquid 1-butyl-3-methylimidazolium chloride ([bmim]Cl) not only enhances the extraction efficiency of camptothecin from the plant bark but also reduces the dependence on harmful organic solvents, thus promoting a sustainable process. Without chromatography, the product is enriched to > 85% purity. Furthermore, optimised conditions with [bmim]Cl at 50 mg/mL for 16 h provided comparable efficiency to 500 mg/mL for 2 h or 1 g/mL for 30 min, demonstrating the potential for scalable, cost-effective production. This approach offers a promising alternative for the large-scale industrial production of camptothecin.