camptothecin

Camptothecin is a natural pentacyclic quinoline alkaloid originally isolated from the bark of Camptotheca acuminata (the "happy tree") native to China[2][5][7]. It is a potent inhibitor of DNA topoisomerase I, an enzyme essential for DNA replication and transcription. Camptothecin binds to the topoisomerase I-DNA complex, stabilizing it and preventing re-ligation of single-strand breaks in DNA. This leads to accumulation of DNA damage and ultimately induces apoptosis in rapidly dividing cells such as cancer cells[1][2][5]. Despite strong anticancer activity observed in preclinical studies and early clinical trials—especially against breast, ovarian, colon, lung, and stomach cancers—its clinical use has been limited by poor water solubility and severe adverse effects[1][2][5][7]. These limitations have led to the development of more soluble analogues such as irinotecan and topotecan that are widely used in cancer chemotherapy today[2][5].

Other names

20(S)-camptothecinCPT(S)-(+)-camptothecin