Alkaloids [Chemical/Ingredient] Camptothecin [Chemical/Ingredient] Camptothecin 1953 C0006812 Camptothecine M0003242 1H-Pyrano(3',4':6,7)indolizino(1,2-b)quinoline-3,14(4H,12H)-dione, 4-ethyl-4-hydroxy-, (S)- D002166 Camptothecin C26362 An alkaloid isolated from the stem wood of the Chinese tree, Camptotheca acuminata. This compound selectively inhibits the nuclear enzyme DNA TOPOISOMERASES, TYPE I. Several semisynthetic analogs of camptothecin have demonstrated antitumor activity. N0000007999