Camptothecin is a potent natural product based anticancer agent isolated from an organic extract of the bark of a Chinese tree, Camptotheca acuminata, Decaisne (Nyssaceae). The chemical identification of camptothecin was first reported in 1966 by Wall et al. (1) as a plant alkaloid which showed strong potency against a number of cancer cells derived from leukemia, small cell lung cancer, and colon and rectal cancer. This communication describes the drug discovery and development process of camptothecin from Camptotheca acuminata at the NCI in collaboration with Monroe E. Wall's group of the Research Triangle Institute and other laboratories facilitated by NCI support. This led to the eventual development of several potent camptothecin analogs, 9-amino camptothecin, topotecan, irinotecan, and rubitecan, which have been approved for cancer therapy against diverse cancer types including different leukemias and lymphoma, small cell lung carcinoma, colon and rectal cancer, cancer of the central nervous system, renal cell carcinoma, ovarian and breast cancer in humans. Topotecan and irinotecan are also currently used in a wide spectrum of clinical trials in patients with metastatic cancers. The resolution of camptothecin action mechanism targeting topoisomerase I provided vital information in cancer drug action, and stimulated novel and rational cancer drug design and development.
Yang, S. S., Cragg, G. M., & Newman, D. J. (2001). The Camptothecin Experience: From Chinese Medicinal Plants to Potent Anti-Cancer Drugs. In Drug Discovery and Traditional Chinese Medicine (pp. 61–74). Springer US. https://doi.org/10.1007/978-1-4615-1455-8_7