camptothecin

noun

camp·​to·​the·​cin ˌkamp-tə-ˈthē-sən 

: an alkaloid C₂₀H₁₆N₂O₄ from the wood of a Chinese tree (Camptotheca acuminata of the family Nyssaceae) that has shown some antileukemic and anticancer activity in animal studies

also : a semisynthetic or synthetic derivative of this