Camptotheca

Camptotheca is a genus of flowering plants in the family Nyssaceae. It is represented by a single widely recognized species, Camptotheca acuminata, native to China and widely cultivated in subtropical regions for the production of camptothecin, an alkaloid used as the basis for several anticancer drugs.

Description and habitat: Camptotheca acuminata is a deciduous tree that can reach modest to medium heights in its native range. It has a slender trunk, an open crown, and simple, ovate to lanceolate leaves. The tree produces small, inconspicuous flowers in loose panicles, followed by dry fruit capsules that contain seeds. It grows naturally in temperate to subtropical forests and is cultivated in many parts of Asia and elsewhere for pharmaceutical purposes.

Chemistry and pharmacology: Camptothecin, the principal alkaloid extracted from Camptotheca acuminata, is concentrated in the bark, leaves, and other tissues. It functions as a topoisomerase I inhibitor, interfering with DNA replication and triggering cell death in rapidly dividing cells. This mechanism underpins its use as a lead compound in anticancer therapy. Derivatives such as topotecan and irinotecan have been developed to improve solubility and safety profiles and are used clinically to treat various cancers.

History and use in medicine: Camptothecin was first isolated in 1966 by researchers at the Indian Institute of Chemical Technology (Hyderabad, India). The discovery spurred the development of semi-synthetic derivatives, notably topotecan and irinotecan, which are employed in chemotherapy regimens for ovarian, colorectal, and other cancers.

Cultivation and conservation: Because camptothecin is a valuable pharmaceutical resource, Camptotheca acuminata is cultivated rather than relied upon from the wild in many areas. Harvesting pressure has prompted interest in sustainable cultivation and alternative production methods.