1H-Pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H,12H)- dione, 10-amino-4-ethyl-4-hydroxy-, (R,S)- 9-AMINO-20-(R,S)-CAMPTOTHECIN 9-AMINO-20-CAMPTOTHECIN NSC629971