10,11-(Methylenedioxy)-20(S)-camptothecin 10,11-Methylenedioxycamptothecin 10H-1,3-Dioxolo(4,5-g)pyrano(3',4':6,7)indolizino(1,2-b)quinoline-8,11(7H,13H)-dione, 7-ethyl-7-hydroxy-, (7S)- 135415-73-5