1H-Pyrano[3',4':6,7]indolizino[1,2-b]quinoline-2,14(4H,12H)-dione, 4-ethyl-4,8-dihydroxy-, (.+-.)- 1H-Pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H,12H)-dione, 4-ethyl-4,8-dihydroxy-, (+-)- CAMPTOTHECIN, +-11-HYDROXY- CAMPTOTHECIN, 11-HYDROXY NSC365729